PDA

View Full Version : Spark's Saga



Richard230
17 January 2011, 1015
For the past several weeks John, my commercial radio station engineering friend, has been helping me attempt to repair my GPR-S (now renamed Sparky, as it rolls off the tongue easier) and get it back on the road – without buying an entire set of new Hi Power batteries (which are not available anyway). We first determined that the Modalis BMS master board had failed. An obvious point of failure was the blackened transistor at the extreme left side of the board. After some searching, my friend found a replacement transistor and installed it on the board. That got the system charging again, but then we found that the BMS was slowly shorting out the batteries under the board and after charging the pack you would return the next morning to find all four of the batteries had discharged below two volts. Without a circuit diagram, which was not forthcoming from Modalis, it was back to the drawing board and we decided to just replace the sucker.

Another very curious discovery was that Electric Motorsport had cut the wires to the 90V to 12V converter, which had blown its 2 amp fuse, and connected the 12 V chassis circuit directly to the four battery pack that was under the Modalis master board. We figured that didn’t help the life of those batteries. All it took was to replace the blown 2 amp fuse which was connected in line to the converter and replace it with a 10 amp fuse. When we hooked up the converter to the main power circuit, the bike powered up and the chassis electrics seem to be working just fine. Neither of us has a clue why the converter was not connected to the power system and why EMS had elected to power the chassis off of four of the batteries, instead of using the converter which was already installed directly under the seat.

The next move was for me to open my wallet and to purchase 24 miniBMS boards and a head-end board from CleanPower Auto. Although they do not take credit cards, they did take my check and I received the boards just two days after they received my funds. We removed the battery packs and then removed all of the Modalis circuit boards. The slave boards still seemed to be performing their BMS function, but with the master board toast and no way to purchase a new one, I gave them to my son-in-law, who might try to sell them on eBay.

Then we performed the somewhat tedious task of hooking up the 24 miniBMS circuit boards (only blowing up one of them when attaching a power cable) and the head-end board. See attached photos of the installation. All seemed well upon completion of the work. The system was now charging steadily until it was cut off by a cell that reached 3.6 volts. This was a big improvement compared to the Modalis system which would cause the charger to cycle on and off every few minutes. For the first time since I owned the bike, Sparky was showing 81 volts, as all of the cells were finally alive and working.

So we installed the bodywork and I jumped on the bike and rode off. It took off with a nice thrust of speed and reached 50 mph quickly. About a mile away, as I stopped for a traffic light, the bike suddenly quit running and after turning the ignition and kill switches off and on to try to reboot it, it still would not move, although all other systems seemed to be working properly. It acted like the “kill switch” was on, no matter if I put it on or off. After about 5 minutes, the bike suddenly and without warning, started up again and I was able to ride another mile, before the same thing happened again. After a few minutes, I was able to ride off again and returned to the shop.

We then checked the operation of the kill switch and brake switches that operate the regen feature of the sepex motor. Everything seemed OK. The regen relay was working and the kill switch seemed to be doing its job. So my friend, who is much heavier than I am, jumped on the bike while I followed on his 1978 Honda CT90 (eek). He was able to ride for five miles without any stalling, although he did use full throttle most of the time and never had to stop for more that a few seconds. When we returned to his shop, he gave me the bike and told me to ride it. As soon as I got on Sparky, it stopped sparking and the main power system would not turn on. Since it was getting dark, we gave up for the day. He told me that the following morning; the bike turned on and ran fine. So we still do not have an explanation for the apparently random stalling when stopped – the power never failed while Sparky was moving. Further investigation is needed, as well as my services to get the bike to stall by showing up.

Personally, I think there is something about me. Dogs hate me and so do electrons. Whenever I get near a dog it barks and lunges at me and when I come close to a piece of electrical equipment it seems to die. The last time I visited Circuit City, their electronic cash register failed just as I arrived at the checkout counter.

So that is the saga so far. I will detail our continued investigations and attempts to get Sparky running (while I am sitting on it) on this thread. Any suggestions are welcome.

Attached are photos of the original Modalis master board, photos of the naked Sparky and the repacked Sparky with the miniBMS boards installed, along with a photo of my friend’s shop.

739741743740742

Richard230
17 January 2011, 1018
Here are a few more photos.

chef
17 January 2011, 1427
Did CleanPower Auto provide instructions on how to interface the Mini BMS's LVC signal to the Sevcon controller? If that signal has a problem it might explain the spurious cutouts. Just speculating here... the voltage level for the LVC signal may not play nicely, there may be spurious noise on the line, the Sevcon may behave differently than the CleanPower Auto guys expected. As a quick & dirty test, disconnect the LVC signal and see how it behaves. But don't leave it disconnected long-term or you'll risk over-discharging them again.

Sounds like you're close to getting the bike back in shape. The final thing left is to program the controller so it doesn't kill the batteries by pulling more than they can handle.

Richard230
17 January 2011, 1523
Chef, my recollection is that CleanPower Auto doesn't mention the Sevcon controller in their published information, but I might have missed something. My friend is reading their entire manual, as well as the Sevcon manual for clues to a potential solution. We did not enable the miniBMS LVC feature because I was worried that the system would cut out under power and that would cause a safety hazard for the rider. I go up and down hills to get anywhere around here and if the the BMS cut the power because a cell dropped below 2 volts for a few seconds it would leave me stranded on a hill in traffic. I would rather the batteries suffer like they have been doing for the past 1500 miles, than take a chance on the power fading at 45 mph while some SUV driver on a cell phone is tailgating me. BTW, the HVC works great when the bike is charging. If I had installed new $$$ batteries I would probably feel differently.

The miniBMS boards have little green lights that are on when the batteries are below 3.6 volts and little red lights come on when the voltage hits 3.6 volts. Charging is then cut off to the pack. After a few minutes, the light may turn green again and then you can cycle the ignition switch and continue charging, until a cell hits 3.6 volts again - but that doesn't get you much added power storage, of course.

The problem with the Sevcon controller is that I can't alter the program parameters that were set by EMS. As it was, EMS claimed to only have one programming gadget and it took them weeks to retrieve it from somewhere so that they could correct the controller so that it would work with their build - or so they told me.

DaveAK
17 January 2011, 1532
The MinBMS can be configured in several different ways. The way I intend to hook it up is such that it reduces throttle by 50% under a LVC warning. This is simply done by hooking it to the 5K throttle via another resistor. It's explained in the manual. I haven't actually hooked up the LVC yet because I haven't got everything back on the bike. I'm not sure if the Sevcon has a suitable input to take the LVC directly.

The Sevcon calibrators are hard to come by. I just managed to get one on eBay finally. I think EMS, Thunderstuck-EV, or Harlan at Hollywood Electrics all have them available to rent. Supposedly the first two just got new stock in after months of them being on order with Sevcon.

chef
17 January 2011, 1601
Yes, what Dave said about the LVC. Properly set up, LVC doesn't completely kill power, it reduces it, alerting the rider and allowing him/her to get home safely (albeit slowly). By not utilizing the LVC, you're wasting half the functionality of the BMS and risking more damage to the cells.

I discussed with CleanPower about using the Mini BMS with the Sevcon controller. They said it would work and that they would provide instructions. Contact them again and give them the exact model of the Sevcon (mine is a PowerPak PP784). As for programming the Sevcon, once again (for the 4th time??) you can rent the gear. It's less expensive than burning out another cell.

Richard230
17 January 2011, 1647
Thanks, Chef. I got the message. I was aware about the result of the miniBMS LVC, but reducing the power amounts to killing it for my type of riding. It would reduce my speed to about 25 mph up hill and that is too low for me. I would like to point out that the Modalis BMS did not have a LVC (at least one that operated) and my batteries survived the treatment. My guess is that the controller was programmed by EMS to compensate for the lack of a LVC. I am going to forward your comments to my friend. The bike is still in his shop. If he thinks that the stalling problem can be solved by reprogramming the controller, then I'll see about renting the calibrator. Right now I don't even know what model of Sevcon controller that I have. In any case, I still think that the controller programming is not causing the stalling problem, as my bike never stalled before and we did not touch the controller or its wiring. My thinking is that we pulled a wire or scraped some insulation, resulting in an intermittent ground, when we were yanking the battery boxes in and out and pulling wires here and there. But then I am just guessing, based upon my previous IC repair experiences. Every electrical problem that I have ever had was caused by bad insulation or corroded contacts or electrical junctions.

frodus
17 January 2011, 1706
Then why even use a BMS? Doesn't sound like you give a crap about those batteries, so why spend the money on protecting them? Balancing is all good and fine, but at the bare MINIMUM you need to do LVC and HVC to protect the batteries. You need to protect the batteries from being overdischarged..... but you don't want to do that at the risk of not having power. Reducing power makes you able to slow down to the side of the road so you can turn the bike off/inspect/recharge..... If you ran out of gas, what does an ICE motorcycle do? It just stops. The LVC is NOT something so you can GET HOME. It's a mechanical/physical indicator that your batteries are too low to continue and you should pull over.

Thank god I don't live around you, I'd rather you pulled off the road slowly than drove home on a pack that could cause problems like overheating/venting/etc and cause you to lose control in front of my vehicle.

ZoomSmith
17 January 2011, 1742
Travis might be on to something. Why not dump the BMS and just display pack voltage for a while? Check your individual cell voltages after each ride.

Your controller probably has an LVC setting too. You might rent the programmer and experiment with the Sevcon LVC, and get a sense of how it affects performance/reliablity. Then put the BMS back on and compare.

Maybe simpler is better?

DaveAK
17 January 2011, 1756
I can't remember exactly how the Sevcon LVC is setup, but basically it's going to reduce power in some way. The MiniBMS can be set up to sound a buzzer when it hits LVC, without affecting power, however if you're half way up a hill and you hit a point where LVC would be triggered, I doubt you'll make it to the top anyway. Something's going to stop you be it a BMS event, controller event or batteries just not having what it takes because they're empty. The order in which I listed them is the preferred sequence.

cycleguy
17 January 2011, 1822
Another very curious discovery was that Electric Motorsport had cut the wires to the 90V to 12V converter, which had blown its 2 amp fuse, and connected the 12 V chassis circuit directly to the four battery pack that was under the Modalis master board. We figured that didn’t help the life of those batteries. All it took was to replace the blown 2 amp fuse which was connected in line to the converter and replace it with a 10 amp fuse. When we hooked up the converter to the main power circuit, the bike powered up and the chassis electrics seem to be working just fine. Neither of us has a clue why the converter was not connected to the power system and why EMS had elected to power the chassis off of four of the batteries, instead of using the converter which was already installed directly under the seat.

This seems odd, why would anyone bypass the dc/dc instead of just replacing a blown fuse. My guess is that perhaps because the dc/dc is NFG, and rather than replace it someone just bypassed it and wired direct to the pack.
You mentioned that your cycle analyst quits when the bike cuts out, do all 12v systems stop functioning? If so, I would look into the dc/dc converter failing.

Also, as soon as you get this problem resolved, you should definitely enable your BMS LVC function. You can set it up to chop the throttle in half as well as to activate a dash warning light at the same time along with the buzzer on the master board. You can adjust the LVC delay by turning the screw on the small blue thing on the master board up to 8 seconds I believe.

chef
17 January 2011, 1858
The MiniBMS can be set up to sound a buzzer when it hits LVC, without affecting power, however if you're half way up a hill and you hit a point where LVC would be triggered, I doubt you'll make it to the top anyway. Something's going to stop you be it a BMS event, controller event or batteries just not having what it takes because they're empty. The order in which I listed them is the preferred sequence.
Yes exactly. By the time the LVC hits, you won't have much juice left in the pack, at least not enough to continue at speed and with enough acceleration. The LVC should be a warning to charge ASAP. But being able to limp home safely sure beats pushing the bike.

EMS probably set the Sevcon with a pack LVC. The problem with monitoring the pack voltage is that the weakest cell(s) can be run into the ground if the other cells are much stronger. For instance, I think yours is set to 50v LVC (give or take). That's about 2.08v/cell for 24 cells. If 23 of the cells are actually 2.1v, the weak cell will be allowed to go to 1.7v. The problem compounds as the weak cell continues to get driven lower. What the BMS gives you is per-cell LVC, preventing any single cell from dropping below the safe voltage. Ideally the cells should be pretty tight, within a couple Ah's. If you've got a weak link in the pack without per-cell LVC, it's going to get destroyed in short order.

Remember that this scenario is toward the end of the pack's energy output. We (ElMotos) have to pay attention to how much is in the pack and plan accordingly. Best to avoid discharging it all the way, avoiding the LVC problem altogether.

chef
17 January 2011, 1906
This seems odd, why would anyone bypass the dc/dc instead of just replacing a blown fuse. My guess is that perhaps because the dc/dc is NFG, and rather than replace it someone just bypassed it and wired direct to the pack.
You mentioned that your cycle analyst quits when the bike cuts out, do all 12v systems stop functioning? If so, I would look into the dc/dc converter failing.

Also, as soon as you get this problem resolved, you should definitely enable your BMS LVC function. You can set it up to chop the throttle in half as well as to activate a dash warning light at the same time along with the buzzer on the master board. You can adjust the LVC delay by turning the screw on the small blue thing on the master board up to 8 seconds I believe.
That's a very good point! You think the kill circuit runs off the DC-DC?

Richard - You might be confusing hard-acceleration LVC with pack-depleted LVC. With the former, your controller is drawing too much current regardless of the pack's SOC -- reprogram the controller. The Mini BMS's LVC delay will help alleviate single cell LVC from cutting power during acceleration.

Richard230
17 January 2011, 1912
I can set the LVC on the miniBMS head board at any time. I just don't want to make any changes until I can get the bike running properly. Again, I point out that everything was working fine until the Modalis BMS failed and started taking out the batteries under the master board. That is why I don't want to mess with the controller. Not only do I not know what changes to make, I have no reason to believe that any changes to the controller programming are necessary, since it was working OK before I installed the miniBMS boards. While I understand mechanical equipment, I have no confidence in my ability to make changes to electrical stuff, especially when it was working OK in the past. I would prefer to understand what might be wrong and then make one change at a time to see if that fixes the problem. That way if there is no improvement, then I can return to the original design or configuration and try something else next. I don't know how the LVC cutoff on the controller would react to the miniBMS LVC cut off. I don't want one system fighting the other.

I did run the battery pack down to where the controller reduced power to a low level one time. So I know that the controller works to protect the entire pack. It just won't protect individual battery cells. I have installed the BMS to make sure that the batteries are equally charged as there is no practical way to access the batteries after each ride to check their voltage when charging. If I can correct the stalling problem that I have, I will try setting the miniBMS LVC and see what happens.

I ordered the miniBMS without the LVC buzzer feature because I would not be able to hear it under the bike's body work, past road/wind noise and past my earplugs that I wear all the time when riding. In any case, I have no plans to run the pack down more than about 50%, so that should protect the batteries from being damaged.

Regarding the DC-DC converter. It is working fine. The CA, all of the lights and the speedometer stay on when the bike stalls out. The only change is that the CA shows no power draw at all when the bike stalls. When it decides to go, it will suddenly show 0.3 kW draw and then I know that I can take off. The 12V chassis circuit seems to be operating just fine. There are no indications that the DC-DC converter is malfunctioning.

frodus
17 January 2011, 2309
Richard,

Its not unbalanced cells that cause you problems. Its an over-discharged or overcharged cell. The BMS balances cells to keep them all the same so they all charge and discharge the same. This creates a pack that is more predictable.

If you're ignoring the LVC and running PAST the time LVC hits, you WILL damage the low battery.

LVC and HVC is what is protecting the cells, not the balancing.


As far as the DC_DC they might have meant to put an inline switch for storing it long term or something and forgot? No reason to disconnect it other than that I'd think.

billmi
18 January 2011, 0649
I would like to point out that the Modalis BMS did not have a LVC (at least one that operated) and my batteries survived the treatment.

Perhaps I'd misunderstood your previous posts. I thought you had two cells that didn't survive being run without a functioning cell level LCV.

The purpose of LVC is to protect the lowest charged cell in the pack from over-discharging - with out it, that cell will be the first to die as your pack approaches complete discharge. Pack LVC in the controller will protect most of the pack, but it won't protect a cell that has a lower charge than the rest of the cells (either from pack imbalance, or just natural differences in capacity between cells) because that cell will bottom out and keep having power driven through it before total voltage from the pack has dropped to the pack LVC level.


I go up and down hills to get anywhere around here and if the the BMS cut the power because a cell dropped below 2 volts for a few seconds it would leave me stranded on a hill in traffic... reducing the power amounts to killing it for my type of riding

The LVC isn't there to say "Hey, don't forget you will need to recharge soon" it's there to say "One of your cells has discharged to the point that if you continue riding, you are going to damage it." That's why it's got a buzzer (the MiniBMS instructions explain how to wire in a buzzer in a place where you can hear it, instead of using one mounted on the board) warning LED (also how to wire it in a place where you can see it is explained in the instructions) and the optional throttle reduction (also covered in the instructions - it's a throttle interrupt, so it's not limited to a particular brand of controller or dependent on an LVC feature in the controller). The reason it's got auditory, visual, and direct protection circuits is because it's *that* important.

Thinking of the LVC warning light as the low fuel light in an internal combustion vehicle, is a recipe for damage. Although it's function is somewhat similar, its importance is very different - in terms of importance it's more like the oil pressure gauge and warning light. When the warning light comes on and the pressure gauge shows you have no oil pressure, that's the sign to maneuver out of traffic and pull over to deal with the situation. If you chose to keep going because it's inconvenient to stop on a hill, you might make it home, you might not, but the damage you do to the engine will be permanent and affect the vehicle's function in the future.


I would rather the batteries suffer like they have been doing for the past 1500 miles, than take a chance on the power fading at 45 mph while some SUV driver on a cell phone is tailgating me.

While not wiring in the throttle-override is certainly do-able, the LVC warning light and buzzer are still the cue to pull over (in fact that's why the throttle override reduces power instead of cutting it, so you can still pull out of traffic safely) and decide what to do - ride a *short* distance at low speed/power draw to a charging point or trailer the bike to a charging point.

Choosing to do it like you've done for the last 1,500 miles may be more convenient for that trip one home, but I can't imagine the cost and time of locating replacement cells is a very economical, practical or enjoyable in the long-run.

The trick to the whole thing is to make sure the pack is balanced and plan your power use so you don't bleed a cell down to the bottom before you're somewhere you can charge, then you'll won't face an LVC warning on the road.

Richard230
18 January 2011, 0926
Thanks for your comments, Billmi. I know that you are right, but I have this fear of making more than one change at a time when working on a motorcycle. My original plan was to enable the LVC once the bike was running well and see how it functions while riding. My concern is that I have one bad cell that seems to charge and discharge more quickly than the other cells and I didn't want that cell to cause driveability problems while I was testing out the repairs. It seemed that since the bike was running relatively well without a functioning LVC it would not hurt to keep things as designed by EMS, at least until I understood more about the functioning of the systems.

Before I realized what was happening, the Modalis BMS had damaged a total of 5 cells, some of these cells have already been replaced, but one is still bad. I was going to wait until I was sure that I had my bike fixed properly before ordering another used replacement cell. However, I really want to solve the closed-throttle stalling problem first. Once that is done, then I plan to order another replacement used HP cell from Harlan and then enable the miniBMS LVC to protect the entire pack. I just didn't know what the LVC would do when enabled. If I had enabled it I would probably think that was causing my stalling problems and I would likely have thought that the LVC was causing the power interruptions. Of course I would have been wrong, but I know that is not the problem for sure now. I do like the idea of installing a remote buzzer. I hadn't thought of that. I agree that I should install the buzzer where I can hear it.

The other thing that concerns me, is that when I visited EMS in December 2009 to buy the bike, the mechanics had just finished building it and when they took it out for a test ride, they could not keep it running for very long. It kept stalling when the throttle was opened, I was told. It took Todd K a month to resolve this issue and his solution required reprogramming the Sevcon controller. I figure that he knows a lot more about the electrical systems on the bike than I ever will and that is why I am trying to be careful with any changes. I might change something that is necessary for the proper operation of the vehicle and never be able to correct the change because I don't understand the overall functioning of the electrical equipment. My friend knows a lot about electronics, but he has no experience with electric vehicles, so it is a learning process for him too. But without a schematic, it is really tough to figure out what is going on and where to look for a fix.

My bike has had a tough life and it needs to be rebuilt one piece at a time and that is what I am trying to do. If I can solve the closed-throttle stalling problem, I can start bringing the bike back to a more normal configuration.

frodus
18 January 2011, 1019
My concern is that I have one bad cell that seems to charge and discharge more quickly than the other cells and I didn't want that cell to cause driveability problems while I was testing out the repairs.
Driveability problems are a lot better than sinking money into more batteries, imho.



It seemed that since the bike was running relatively well without a functioning LVC it would not hurt to keep things as designed by EMS, at least until I understood more about the functioning of the systems. But it doesn't seem that "things as designed by EMS" worked well with these batteries. I mean, you do have weak/damaged cells, right? That one cell is the weakest part of the pack. Replace it if you can.



I really want to solve the closed-throttle stalling problem first. Once that is done, then I plan to order another replacement used HP cell from Harlan and then enable the miniBMS LVC to protect the entire pack. I just didn't know what the LVC would do when enabled. If I had enabled it I would probably think that was causing my stalling problems and I would likely have thought that the LVC was causing the power interruptions. Of course I would have been wrong, but I know that is not the problem for sure now. I do like the idea of installing a remote buzzer. I hadn't thought of that. I agree that I should install the buzzer where I can hear it.
Now I see where you were going. Debug each system independantly. It sounded like you weren't ever going to use an LVC by your wording. I agree, work out the kinks first, but please do enable the buzzer or an LED. At least that will help you with identifying battery problems while you're testing.

DaveAK
18 January 2011, 1025
Now I see where you were going. Debug each system independantly. It sounded like you weren't ever going to use an LVC by your wording. I agree, work out the kinks first, but please do enable the buzzer or an LED. At least that will help you with identifying battery problems while you're testing.
I agree with enabling the buzzer. This might help you with identifying your throttle problem. With just the buzzer the LVC won't effect any other system, but if it sounds while you're experiencing the throttle problem it's an indication that it's an LVC issue. If it doesn't sound it won't get in the way of debugging the throttle problem as it won't have any effect on it.

billmi
18 January 2011, 1032
Now I see where you were going. Debug each system independantly. It sounded like you weren't ever going to use an LVC by your wording. I agree, work out the kinks first, but please do enable the buzzer or an LED. At least that will help you with identifying battery problems while you're testing.

Yep, especially if running without replacing the suspect cell yet - having the visual and or auditory LVC warning will let you know when you've hit the capacity limit of that weak cell while you are testing. Setting up the MiniBMS LVC buzzer and LED won't affect the rest of the systems. Since you've got the MiniBMS modules on the battery, they're going to trip LVC when a cell goes low - the only difference is that with the buzzer and LED, the head board will be able to tell you that they've tripped.

chef
18 January 2011, 1229
As far as the DC_DC they might have meant to put an inline switch for storing it long term or something and forgot? No reason to disconnect it other than that I'd think.How common are DC-DC's that support 50-80v range? If the voltage strays outside the DC's working range, what typically happens? Does the output voltage sage/surge, or does it just drop out completely?

Keep in mind that EMS uses some fairly cheap parts, aside from the main components such as motor/controller. I doubt he has a high-end DC-DC in there. The one in mine looks super cheap, like something hand-soldered in China.

frodus
18 January 2011, 1254
not sure how common they are.... but the 72V DC-DC I've got on my desk is 55-100V swing. If it strays outside, it just doesn't work if its too low, or it might fry if the voltage goes too high. They don't usually operate outside their spec. A GOOD DC-DC will not let the voltage on the output drop if the input voltage drops. It will draw more current and drop the output current as needed to keep that voltage regulated.

If you have a REALLY wide range, you should use an Aux battery and ensure it won't go overvoltage and use a DC-DC converter + aux battery in parallel in case the input to the DC-DC drops. That way, its redundant. Its what I'm doing.

Richard230
18 January 2011, 1624
Thinking about my problem today, after reading the comments above, it does seem that logically the DC-DC converter might be causing some sort of problem when the throttle is closed for more than a minute or so. I think my next plan is to hook up a volt meter to the 12 volt chassis system and drive around to see what voltage is being produced when the bike is running and when the throttle is closed. Maybe the voltage is too low to activate the relay that powers up the sepex motor. (Keep in mind that I continue to be confused what causes the system to switch from its regen feature to its power operation when the motor comes to a stop. I know there is something going on because I can hear a relay click and see the display on the CA go from a positive 16 amps to around .5 amps, just as the motor stops rotating.) Right now, when the system fails, it will go from a reading of .5 amps to 0.00 amps when stopped without warning and then it will take a few minutes before the system will come on again. It sure seems like something is getting hot and then needs to cool off before working again. And it continues to defy logic that the problem has never occurred when the bike is moving, only when it is stopped.

Attached is a photo of someone else's DC-DC converter (that I inserted and then couldn't figure out how to delete) on the left and a photo of my converter in the middle. You can also see it on the right-side photo of my bike.

chef
18 January 2011, 1820
That's my DC-DC. I can tell by the taps used to power the USB port :)

Richard230
21 January 2011, 1630
My friend, who is helping me with my GPR-S, contacted a Sevcon expert today about the controller and here is the message that he sent me:

1. The Sevcon Powerpak SEM (Model # 632S84622) you have is not RS-232/PC programmable, however other models are, the one on your motorcycle is not.

2. He says we need to get the programmer to pull the error code to try and pinpoint the reason controller is shutting down, After going through what little wiring there is on the bike I am convinced it's most likely not an external wiring issue.

3. The programmer will provide us with Diagnostic information to help trouble shoot the problem. I have a call into the Sevcon Distributor, Alternative Fuels Equipment, 440-232-4111 to try and get a price on the programmer. It's not in stock at Alternative Fuels Equipment and will need to be ordered from Sevcon, and from what I gather the US office doesn't have any ether and it will require an order to the UK.

Anyone happen to know a source for a Sevcon programmer in the US?

cycleguy
21 January 2011, 1701
I can hear a relay click and see the display on the CA go from a positive 16 amps to around .5 amps, just as the motor stops rotating.)

I'm not completely familiar with your setup, but what relay are you talking about?
Are you hearing the contactor shut off? What is the function of the relay you're referring to?

DaveAK
21 January 2011, 1724
Anyone happen to know a source for a Sevcon programmer in the US?
Thunderstruck-EV and Electricmotorsport both were expecting deliveries at the end of last year. They both used to rent units, and I think they still do, as does Harlan at Hollywood Electrics.

I have a used one on its way to me and if you strike out with getting one I'll lend you mine. You'll have to wait a couple of weeks though as I want to play with it first. :)

Richard230
21 January 2011, 1904
I'm not completely familiar with your setup, but what relay are you talking about?
Are you hearing the contactor shut off? What is the function of the relay you're referring to?

When you turn on the ignition key, after about two seconds there is a loud click from a remote electromagnet switch that powers up the system. Normally, what you do is to wait for this click and flip the kill switch on and then the bike will move forward with a turn of the throttle. A much simpler procedure than used by Brammo or Zero.

My problem is that even after hearing the relay click, the bike will not move. This seems to occur when the vehicle has been running for a short while and then if you stop for a minute or so, the bike will not move, until I let it sit for a couple of minutes. Then it will run again. It only happens with the throttle closed for more than about 30 seconds. If you come up to a stop sign, stop and then take off immediately, it will keep running. But you want to avoid traffic lights or you will end up stalling and blocking traffic.

I never had this problem until I took all of the batteries out of my bike and reinstalled them with the new miniBMS system. However, I do recall that when the bike was new, for the first 300 miles something similar would happen, but this was under full throttle. Sort of the opposite of what is happening now. The previous "stalling" occurred randomly for the first 300 miles and then went away. I never did discover what caused that problem or what made it disappear.

Richard230
21 January 2011, 1909
Thunderstruck-EV and Electricmotorsport both were expecting deliveries at the end of last year. They both used to rent units, and I think they still do, as does Harlan at Hollywood Electrics.

I have a used one on its way to me and if you strike out with getting one I'll lend you mine. You'll have to wait a couple of weeks though as I want to play with it first. :)

Thanks Dave. I would like to buy a programmer to use now and to potentially use in the future when the batteries eventually get replaced with something better. I'll give Thunderstruck or EMS a try. My friend didn't mention if he asked the expert your question about the controller. I am meeting him on Sunday and will ask him in person if he remembered to ask.

cycleguy
21 January 2011, 2006
When you turn on the ignition key, after about two seconds there is a loud click from a remote electromagnet switch that powers up the system. Normally, what you do is to wait for this click and flip the kill switch on and then the bike will move forward with a turn of the throttle. A much simpler procedure than used by Brammo or Zero.

My problem is that even after hearing the relay click, the bike will not move. This seems to occur when the vehicle has been running for a short while and then if you stop for a minute or so, the bike will not move, until I let it sit for a couple of minutes. Then it will run again. It only happens with the throttle closed for more than about 30 seconds. If you come up to a stop sign, stop and then take off immediately, it will keep running. But you want to avoid traffic lights or you will end up stalling and blocking traffic.

I never had this problem until I took all of the batteries out of my bike and reinstalled them with the new miniBMS system. However, I do recall that when the bike was new, for the first 300 miles something similar would happen, but this was under full throttle. Sort of the opposite of what is happening now. The previous "stalling" occurred randomly for the first 300 miles and then went away. I never did discover what caused that problem or what made it disappear.

Sounds odd to me, if the ignition switch closes the contactor (electromagnetic switch) which connects pack voltage to the controller, why is closing the kill switch necessary to make the bike move. Does the kill switch turn on your 12V system, or is that turned on with the ignition key as well? How does the kill switch disable the controller even though the contactor is closed?

DaveAK
21 January 2011, 2017
Here's what little I know about the Sevcon. Ignition key powers up the controller. The two second delay is the internal pre-charge circuit before energizing the contactor coil, (the click). The kill switch is most likely connected to one of the safety interlocks that forklifts use, such as seat switch or belly switch, although it could simply be connected to the forward direction switch. The controller has a specific start up sequence, which I can't remember off the top of my head. Under certain situations, depending which safety circuit is tripped you have to power off the controller and power on again. I'll dig out the manual later and see if I can find the right section.

Richard, one thing you're going to need to know is which switches are wired in to which inputs on the controller. This will give you an indication of what it's supposed to be doing.

chef
21 January 2011, 2306
Sounds odd to me, if the ignition switch closes the contactor (electromagnetic switch) which connects pack voltage to the controller, why is closing the kill switch necessary to make the bike move. Does the kill switch turn on your 12V system, or is that turned on with the ignition key as well? How does the kill switch disable the controller even though the contactor is closed? What EMS did was wire both the brakes and "kill switch" to the Sevcon's regen signal. Flipping the kill switch causes a momentary buzz due to the regen briefly activating (quits immediately since it detects the bike isn't moving). The kill switch doesn't actually cut power to the rest of the bike's systems, it just prevents the controller from sending forward power to the motor (because regen is engaged).
That signal must also incorporate a power-on safety function. When the bike is first turned on, the throttle is disabled until the regen signal is engaged through either the kill switch or brakes.

Richard230
22 January 2011, 0849
Sounds odd to me, if the ignition switch closes the contactor (electromagnetic switch) which connects pack voltage to the controller, why is closing the kill switch necessary to make the bike move. Does the kill switch turn on your 12V system, or is that turned on with the ignition key as well? How does the kill switch disable the controller even though the contactor is closed?

The ignition switch turns on the 12V chassis power, but the start-up procedure has to be followed in a certain way to get the power circuit going. First you have to have the kill switch off. Then you have to turn on the ignition. Then you wait until the main contactor relay makes its loud click. Then you turn on the kill switch and only then are you ready to ride off. If you don't follow this process exactly, the bike's lights and instruments come on but you go nowhere.

chef
22 January 2011, 1000
Another procedure works: with bike off, set kill switch to running position (that is, kill disabled). Turn bike on, then briefly pull in the brakes. Throttle should activate. It's because the kill switch is tied to the regen signal as I stated above.

Richard230
22 January 2011, 1605
Another procedure works: with bike off, set kill switch to running position (that is, kill disabled). Turn bike on, then briefly pull in the brakes. Throttle should activate. It's because the kill switch is tied to the regen signal as I stated above.

Thanks Chef. I'll give that a try.

I passed along your and Dave's comments to my friend who is stuck with my bike and he liked them. It gave him some more ideas to test.

jazclrint
22 January 2011, 1909
Hey Richard,
I was just an airplane electrician in the Navy, I'm not an engineer by any means, and I haven't followed your adventures with this bike completely. But I'll say this, your trouble shooting method seems very sound, so stick with it. It sounds like to me, and this is just from reading this thread (well mostly) that something is over heating,and/ or maybe over currenting(?), and causing a failsafe to activate. Is it possible that one of your batteries is just done? You mentioned it acted similar but at full throttle when it was new. Maybe that was because the pack was new and everything was settling in? And now you have the opposite problem? I'm the captain of over simplification, so take that as you may.

Richard230
22 January 2011, 1914
Thanks, jazclrint. Join the club. I always try the simple and easy stuff first, even if it doesn't make any sense to more knowledgeable people. Usually though, most problems that happen without warning are usually simple, like a broken wire or a bad contact. Of course, the hard part is finding the problem and sometimes the harder you look the harder the problem is to see.

jazclrint
22 January 2011, 1925
Haha. Tell me about it. Try working on 30 year old Navy aircraft. :D This is why I prefer to teach little kids to play recorders or band instruments. Although troubleshooting why a student can't do something on their instrument when you can see in their mouths is about as hard as trying to find an intermittent fault in an electrical circuit. :D

chef
23 January 2011, 0834
My problem is that even after hearing the relay click, the bike will not move. This seems to occur when the vehicle has been running for a short while and then if you stop for a minute or so, the bike will not move, until I let it sit for a couple of minutes. Then it will run again. It only happens with the throttle closed for more than about 30 seconds.
I wonder if the regen is inadvertently getting activated when your bike stalls. When that happens, are all the electronic systems still functional - speedo, CA, headlights, running lights ... ? If so, next time the bike stalls out, pull in the brakes and listen for the momentary regen buzz. If it doesn't buzz, check the wiring from the brakes and kill switch. On my bike the brake signals go to a small box which somehow makes its way to the controller.

Richard230
23 January 2011, 1620
I wonder if the regen is inadvertently getting activated when your bike stalls. When that happens, are all the electronic systems still functional - speedo, CA, headlights, running lights ... ? If so, next time the bike stalls out, pull in the brakes and listen for the momentary regen buzz. If it doesn't buzz, check the wiring from the brakes and kill switch. On my bike the brake signals go to a small box which somehow makes its way to the controller.

When I come to a stop, the brakes activate the regen and the system buzzes when it switches over from braking to going. But shortly the CA will drop from a slight draw (to power the motor's magnets?) to nothing and then the throttle will not operate. However, all of the 12V chassis equipment works when that happens. The headlight, the taillight, the brake light, the blinkers and the horn all function normally, the bike just won't move forward - until it feels like it. That is what is puzzling. It will run again, it just wants to rest for a while. At least the power doesn't cut out when I am moving, that could be more dangerous than dieing at a stop - which tends to be sort of embarrassing when the cars behind you want to go and you are blocking their progress.

We did find the device that makes the buzzing noise and activates the regen. It is in a relay-like housing directly under the seat and contains an electromagnet that buzzes close when the brake lever is pulled. It works even when the motive power will not.

cycleguy
23 January 2011, 1740
We did find the device that makes the buzzing noise and activates the regen. It is in a relay-like housing directly under the seat and contains an electromagnet that buzzes close when the brake lever is pulled. It works even when the motive power will not.

Relays shouldn't buzz, just click once to turn on or off. Have you thought about bypassing the relay? In other words, temporarily disable the regen function, perhaps the relay is getting stuck in regen mode and won't allow the controller to recognize throttle input.

magicsmoke
23 January 2011, 1837
Hi Richard, I don't want to muddy your train of thought on this stalling prob but the LVC, regen, throttle things just don't feel right.
Does your harness include a motor temp sensor?
My gut feeling is that the motor is running hot or the sensor is faulty or the Sevcon parameter is wrong.
Based on your saying that this only happens if you stop for a prolonged time, I'm thinking that when the motor is running, the cooling effect of the rotor is disguising the issue, and when stopped the temp will rise and trigger the 'cutout'. Waiting a couple of minutes or so longer and the 'cutout' resets.

If however you don't have a sensor then I'll go and feel something else :)

Rob

DaveAK
23 January 2011, 1858
Hey Rob, there is no temp sensor input into the Sevcon, however, what about internal temp sensors? Is there anything that might cause the controler to overheat when stationary? (This should flash the LED 8 times.)

Richard230
23 January 2011, 1915
Relays shouldn't buzz, just click once to turn on or off. Have you thought about bypassing the relay? In other words, temporarily disable the regen function, perhaps the relay is getting stuck in regen mode and won't allow the controller to recognize throttle input.

Chef also suggested that course of action and we are going to give that a try the next time we mess with the bike.

You are correct, the buzzer buzzes once and that apparently turns on the regen function. I was just fascinated to watch the electromagnet do its thing whenever the brake lever was pulled. It doesn't click though, it actually buzzes.

Richard230
23 January 2011, 1924
Hey Rob, there is no temp sensor input into the Sevcon, however, what about internal temp sensors? Is there anything that might cause the controler to overheat when stationary? (This should flash the LED 8 times.)

Rob, I am sure that the motor is not overheating. I can put my hand on it and the end is barely warm. However, when running on the freeway last year, it would get quite hot. My thermometer would show about 165 degrees when pointed at the inside of the motor (the end of which looks like Swiss cheese). But I haven't had the bike running long enough to warm up that big hunk of wire since I replace the BMS. Also, you don't need to stop for more than a few seconds for the power to shut off. It seems like coming to a complete stop causes the problem - but not every time (just most of the time). Also, when that motor gets hot, it takes forever to cool off, whereas when the power shuts off it "only" takes about 5 minutes of sitting around to come back on.

Dave, I haven't noticed any LEDs on the controller. Where are they located? Flashing LEDs would be interesting.

Attached is a photo of the controller.

chef
08 February 2011, 0011
I guess it's my turn to add to the sordid tale of the EMS Modalis BMS. My 24-cell 40Ah TS pack had been capacity challenged from the start. I didn't know it at the time but the Modalis was rapidly killing the weaker cells by allowing the voltage to go too high (4.2v) boiling off electrolyte. I knew there was at least 1 bad cell but didn't have a good way to test them individually. Luckily I found someone locally with industrial battery capacity testing gear (the company produces LiPo cells). From the results below, you can see that the pack is FUBAR'd :( Only 9 of the 24 are anywhere near the original 40Ah capacity.

Discharge tests were done at 1C and LVC of 2.55v. Two runs for each cell charged at 1/4C to 3.65v. I've grouped them by average capacity. The cells in each group are typically +/- 2Ah from the average.

9 cells @ 35Ah (87.5%)
1 cell @ 31Ah (77.5%)
11 cells @ 23Ah (57.5%)
3 cells @ 16Ah (40%)

Max cell is 37Ah, min cell is 15.7Ah.

Richard230
08 February 2011, 0844
Now what do we do, Chef? I am running out of ideas. Maybe the GPR-S needs to be converted to a gas engine. I think Harbor Freight probably has some IC engines that would fit in the frame. :O

NonPolluter
08 February 2011, 1500
Now what do we do, Chef? I am running out of ideas. Maybe the GPR-S needs to be converted to a gas engine. I think Harbor Freight probably has some IC engines that would fit in the frame. :O

You could also go hybrid. There are two successful implementations that I know of:

A EVT-168 electric scooter who lugs a Honda genset between his feet and charges his batteries at the same time.

A homebuilt electric motorcycle on EVALBUM.com with a gas genset installed in the frame. He rides this 12 months a year in Northern BC.

HighlanderMWC
08 February 2011, 1531
Um, with his batteries I don't think a genset is the way to go.

Richard230
08 February 2011, 1555
I now have a copy of the Sevcon controller hand-held programmer manual. It is titled: Sevcon PowerpaK, SEM Including MicropaK. If anyone needs it, send me a PM and your e-mail address and I will send you the manual.

Richard230
08 February 2011, 1911
With the help of the programmer manual we now know (sort of) what has been causing the stalling problem. The Sevcon controller says: that I have putting my motorcycle into reverse before forward motion stops - resulting in forward motion being locked out. Why that is happening is another question and why it is happening since we installed the new mini-BMS (and of course took much of the battery packs apart in the process) and reconnected the DC-DC converter, is a mystery at the moment. Hopefully, more messing around will correct the problem. The saga continues.

DaveAK
08 February 2011, 1915
Sounds like you're getting somewhere Richard. Hope you figure it out soon.

chef
09 February 2011, 0107
Now what do we do, Chef? I am running out of ideas. Maybe the GPR-S needs to be converted to a gas engine.That would be sadly ironic. The balance of the universe would be thrown off, angels would cry, and somewhere a puppy would die... :rolleyes:

A new pack would do wonders for your bike. Now that you have a lead on the stalling problem all that needs to be done is replace the pack. I'm putting EIG cells in mine, same as the GPR-S that I got from JK. I'm curious to see how the D&D screams with the Sevcon maxed out @ 425A :D

BTW - on the stalling issue, temporarily disconnect the buzzing relay box that signals regen. If that takes care of the stalling, it's a place to start diagnosing.

Richard230
09 February 2011, 0857
Chef, I think the same thing about the regen circuit. We believe there is something going on that is sending the wrong signal to the controller at the wrong time. We tried the bike out with the regen disconnected and it ran fine, but not for long enough to prove anything, as two of the batteries blew up before we got very far.

As far as putting new batteries into the bike, that is the last thing I will do. I am not going to throw good (and expensive) batteries after bad until I know for sure that all of the bike's problems are completely resolved. I am willing to trash the rest of my current batteries (since they are toast anyway) while we get everything sorted out. Even if they will only hold enough power to run a few miles, that still beats pushing. But I am thinking about installing some backup pedals just in case. :D

Richard230
14 February 2011, 0852
We may be getting closer to solving the stalling problem in my GPR-S. My electrical guru friend now thinks that the problem is a intermittently malfunctioning ignition switch, that is cutting out when the handlebars are turned to the right. When that happens a signal is sent to the controller that the switch has been turned off, then immediately the current comes back on and the controller gets confused and decides to get temperamental due to conflicting inputs and goes on strike for a while. His plan is to buy a new switch. So the story continues.

Hopefully, once that is fixed, we will also be able to find the reason for the last two batteries at the end of the pack getting fried when the throttle is opened for too long. In the meantime we are dialing back the amps, but the problem remains that it takes at least 150 amps to get up the hills in my neighborhood at a reasonable speed to keep up with car traffic. On the other hand, if it was flat around here, I would likely be peddling my bicycle more and riding my electric motorcycle less.

harlan
14 February 2011, 0944
Richard,

I've had a similar problem before with a GPRS. However it wasn't the ignition switch that was causing the problem, it was a bad connection in the connector that hooks the ignition switch up to the rest of the wiring harness.

Richard230
14 February 2011, 1345
Thanks Harlan. That is good to know. I'll pass the information along to my friend.

Richard230
21 March 2011, 1521
I am happy to report that my stalling problem seems to have been fixed - thanks to Harlan's advice. He was right on. After much investigation with the controller programmer, we found that power was being cut off when the bars were turned to the right. When that happened the Sevcon controller would go on strike for three minutes (fortunately it wasn't an Italian controller otherwise it would have been on strike for months) and then reset and power up the motor again. The controller is apparently designed for industrial equipment and that is probably a safety feature to prevent an unexpected equipment start, which could be dangerous when using something like a forklift.

Anyway, after much riding around and poking around, we found a mangled wire where the sun don't shine that was probably damaged during the removal and re-installation of the battery boxes when the Mini-BMS system was installed, which replacing the original Modus system. That wire must have been broken and perhaps was interrupting the current when turning the bars, which likely pulled on the wire and separated it where broken. Then when straightening out the bars, contact would be re-established. At least that seems like a reasonable explanation.

So now I am back on the road, although now with a tired bunch of batteries - no doubt no thanks to a combination of the Modus BMS failure and a probably a too-large and demanding sepex motor.

chef
21 March 2011, 2308
That's good news. The remaining component to address is the battery (and related items such as adjusting the controller to prevent overdraw). CALB (Sky Energy) 60Ah cells would suit your needs... 3C (180A) continuous. LiPo would be even better if you can source them. The hills I've tested the LiPo GPR-S on have shown draws of 170A up a 1/2 mi 10% grade hill and 190A on a steeper but shorter hill. The bike is able to sustain 52mph up Tumbleweed Hill (the 1/2mi 10% grade, bigger than it might sound).

Richard230
22 March 2011, 0749
I am still trying to come to grips with the performance of my original 2008-model, 60V, 50 Ah Hi Power, RT-motor, GPR-S. Not only would it draw a continuous 8.5 kW up hill, but I was able to ride it up two miles of a 6% freeway hill at steady 55 mph. Top speed was 65 mph, about 10% higher than my 72V D&D version. I keep thinking that the performance of that bike was why EMS was happy to trade it in for my sepex-motor model.

harlan
22 March 2011, 0829
Glad to hear you found that gremlin.

The performance out of your Sepex bike was probably at one time as good, if not better than the your RT bike, but unfortunately as you've discovered they weren't really up to the task and are now weak and will have to be retired prematurely.

Richard230
22 March 2011, 0927
I agree. But I am going to let someone else stick new batteries into that chassis. My plan is to purchase a Brammo Empulse when they become available and give the GPR-S to my son-in-law (if he will take it). I now know that I do not have the knowledge or skills to try to salvage the GPR-S and turn it into a good runner. Plus, no matter what is done to that bike, it will never match the Empulse's range or performance. The GPR-S chassis great for a hobbyist as it is simple and easy to work on, but my hobbies were never focused on anything electrical, just mechanical - and motorcycle riding, of course.