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teddillard
21 March 2012, 0313
We've seen a few examples of modular packs. My questions... why not? Has anyone here played with this idea?

It seems to make perfect sense to me, and N&V and I have had a little discussion on it on my post:
http://evmc2.wordpress.com/2012/03/18/swappable-batteries-tell-me-again-why-not/

My concept is to build a bike with smaller, modular packs. They interchange for fast swap out with fully charged packs. They can be paralleled for adding capacity, by adding more packs (for when you want range, and don't mind the weight...), like that.

Think cordless power tools.

Right now my work on the R5e II is centering around doing this. I have a basic pack now that's 20 lipo packs- 74V 20ah that weighs 25lbs or so. I have an enclosure that would fit in two places- under the motor, and in front of the motor (where my pack is now). It would hot-swap out, 4 pins holding it in place.

I could run the bike with one pack, and thus strip 25lbs off it, and get very short range but good performance. I could run it with both for more practical range. I could swap them out at will, with fully charged packs, either for track purposes or commuting or whatever.

Some working shots:

The mockup of the module:
https://fbcdn-sphotos-a.akamaihd.net/hphotos-ak-snc7/416922_3628720196149_1218396040_33668590_132035102 6_n.jpg

earlier mockups:
https://fbcdn-sphotos-a.akamaihd.net/hphotos-ak-ash4/432072_3439886035413_1218396040_33581163_120665796 5_n.jpg

I'd love to hear some thoughts on this concept. It's basically a "system" design philosophy, similar to the battery modules for any power tool kit (a pretty well-proven model), the same idea as standardizing flashlight batteries, even the same concept as the professional camera systems like Hasselblad, Canon and Nikon. To use that example, the lens is really one of the biggest expenses, so why not make them interchangeable and standardized? Ditto with the batteries on a bike.

If I were a company like Brammo (while I'm at it, if I were rich and good-lookin :D) with a line of ten machines, why wouldn't I want to standardize a battery module? Decide on a basic voltage for your systems. Build a pack that, by itself, could power your smallest bike, make it a hot-swap. For bigger bikes run multiples. You have a little trail bike, you have a nice little 74V pack you can swap out with spares you have in the truck. You have a commuter, you're running 2 or 4 of these. The customer buys the basic bike, adds more modules to their collection as they see fit. You get a big bike like the Empulse, you're running more - maybe 6? I dunno, I'm just throwing these numbers out there. But on a bike like that, you could hot-swap the pack for your sunday runs, or your racing, or whatever.

You could even sell accessory packs that go on the bike like saddlebags for an ultra-high-range configuration.

Not picking on Brammo here, (since everybody's so sensitive lately), but it's a good example of a line of products where this could be implemented. One of the main motivations for me is my new trail bike project... if I have a module that I design well, I can pop the batteries out of my daily ride and into my dirt bike for the weekend. See how neat this idea is?

Even for me there's the economy of scale since I could make one design, have it waterjetted in bunches of 4 at a time, and slap packs between bikes. When you're talking about a manufacturer it seems like a game-changer. You make ten bikes, and one battery module design. Cost of design and production go down, cost of bike goes down, profits go up. (Imagine if Makita made a different battery for every power tool they made.)

This seems to me to be thinking that's "out of the box" for ICE and motorcycles, but totally "inside the box" thinking for electric powered devices - even to the point of it being kind of a "duh" no-brainer.

Here are some other little benefits. Smaller charger since recharge time can be longer. Less stress on the batteries from a slower charge. Smaller BMS or balance charging system. Better balancing. How'm I doin'?

OK, that's my morning thought. Now for my Cheerios. :D

mpipes
21 March 2012, 0539
Makes sense to me Ted.

I can see issues when considering entry level product lines with the higher end product. Maybe the higher end product has a different battery chemistry which is more expensive and doesn't allow the entry level to be as cost competitive. On the other hand if both chemistry packs were built with the same formatting, the higher end bike now has a middle range price point available thanks to the entry level pack. Maybe a pack that fits the entry level well, means on a larger bike you have too many individual packs to swap out. Minor details.

I'm a product designer at work and keeping our products compatible across all product lines is the name of the game. When we can't make something truly universal, we at least stick to the same basic concept - ie: in the field, the installation method may still be the same across all products, or on a steel assembly it's simply one component to swap out to make work on all products.

Simplicity, Repeatability, Compatibility, and

teddillard
21 March 2012, 0549
...and? ...and? lol!

Lyconthrous
21 March 2012, 0625
I can see the use of the hot swap pack on the track. But didn't even think of commuting till I saw this thread. If your work was at the end of the range of your EV, then you could keep a pack at work and 1 at home. The cost of an extra charger for each location needs to be factored in. But it does make sense.

protomech
21 March 2012, 0632
For what it's worth, I think Brammo and Zero are both at least thinking in this direction.

Zero has 3 current pack configurations (my best guess, anyhow): ZF3 (18s2p 20ah pouches), ZF6 (18s4p 20ah pouches), ZF9 (18s6p 20ah pouches). ZF3 is the only one that is removable, and it's a 40 lb brick. Maybe harder to work with than your (presumably) smaller hobbyking lipo blocks.

Brammo has a similar lineup for Enertia Classic and Enertia+: 2x BPM 44/70 (12s2p 35ah pouches) in E+, probably 2x BPM 44/35 (12s1p 35 ah pouches). I suspect the Empulse will use a 24s2p and 24s3p configuration of the same 35ah pouches.

One problem is that building a modular pack requires extra packaging space and extra structural support to accept the modules. Sort of like Apple did with their macbook line, using an integrated battery allows you to use more of the packaging/weight budget for batteries.

The choice might be something like a 4x 2kWh modular configuration vs a 9 kWh integrated configuration for the same cost and the same weight/packaging. It might be more complicated than that, too; let's say your motor is 30kW continuous, so if you want to power the bike with 1 module then it needs to do 15C sustained. That means you probably need to use power chemistries and the excess power will go unused when you have all 4 modules in place. (of course you could buy 1-2 power module and 4 energy modules, and just use one set or the other). The integrated pack only has to do 3.3C sustained, so it can use an energy chemistry and possibly gain even more capacity or decrease its weight.

There's definitely a number of people on brammoforum that have brought up the idea of saddlebag pack extenders. And you could do something like an integrated pack base, and plugs to support additional "clip-on" packs. Zero could bring out something like a ZF6 S + a ZF3 removable pack.

CharlesZaden
21 March 2012, 0808
I can see issues when considering entry level product lines with the higher end product.
Yeah this is about the only problem I could see from a production standpoint.
Other than that this idea sounds great to me especially in the context of a trail bike made for quick, hard runs.


If your work was at the end of the range of your EV, then you could keep a pack at work and 1 at home.
yeah I would not sleep well knowing that I had over a grand sitting in my office just waiting for the cleaning staff haha

Skeezmour
21 March 2012, 0922
Well I love that idea :) Wish I had thought to do it.....oh wait I already did and so far it is GREAT! So in it right now sits 72v 32ah with BMS inside the same box. Next pack will be 120v and 30ah with the BMS setup on quick connects. I could go down to 120v and 25ah and get it all inside the box if I so choose. Granted this is a bigger building block than if I was going to try and make a full on retail product out of it.

Look forward to seeing more versions of this concept.

29032904

teddillard
21 March 2012, 0942
Got any shots of it out of the bike?

Skeezmour
21 March 2012, 1019
29082909




I will pull the pack tonight and snap a few more pics. I will also add a few of the pack prior to going in the box.

Fun thing is the entire front pack on the Mustang we are converting for a shop car this week is all built on the modular concepts. Few minutes and the 4 packs of 8s 90ah can be pulled from the car. The back pack can also be pulled quickly but not as fast.

liveforphysics
21 March 2012, 1102
The modular pack concept has been the industry standard in electric bicycles for >10 years. This isn't saying there aren't companies that make the packs built-into the frame and not swappable or expandable, but the standard is packs in sections of extruded aluminum tubing that you slide into a mating socket on the bike.

You have a pack you can charge off-bike or on-bike, it has a socket it mounts upon on the bike, you can add as many sockets for batteries as you can find space for.

It's nice for folks in apartments or folks who don't have the range to make it round-trip, because they can simply remove the pack in 5seconds and carry it into work or school etc to get plugged in and charge for the ride home.

Skeezmour
21 March 2012, 1259
The modular pack concept has been the industry standard in electric bicycles for >10 years. This isn't saying there aren't companies that make the packs built-into the frame and not swappable or expandable, but the standard is packs in sections of extruded aluminum tubing that you slide into a mating socket on the bike.

You have a pack you can charge off-bike or on-bike, it has a socket it mounts upon on the bike, you can add as many sockets for batteries as you can find space for.

It's nice for folks in apartments or folks who don't have the range to make it round-trip, because they can simply remove the pack in 5seconds and carry it into work or school etc to get plugged in and charge for the ride home.

I'm looking to show the next step for this. A pack that runs my EXR1.0 that can also pop into one of my street bikes or quad then right into my car. To me this is about one of the most exciting parts of electrics. I can buy the major componets and use them in multiple vehichles. The controller going in my street bike will be more than capable of running my BMW 528i when I ever get the funds and time to convert it.

mpipes
21 March 2012, 1309
...and? ...and? lol!

and I apparently drink too much coffee in the rush to get to the gym in the morning... I completely forget where I was going with that.. LOL!

Ken Will
22 March 2012, 0552
I imagine 450 amp plugs are rather expensive, but bolt terminals would only take a few seconds to disconnect/reconnect.
Just use wing-nuts so you don't need a wrench.

A fire-proof container would be nice!

Please design them so 2 will fit in my Honda. (you know the bike:rolleyes:)

teddillard
22 March 2012, 0747
Piece o' cake. I was thinking the big Anderson connectors they use for forktrucks and stuff.

Skeezmour
22 March 2012, 0802
Anderson SB350 will take up to 350 amps continuous and up to 4/0 cable. They also make a smaller SB175 that is plenty for a normal elmoto. I personaly like the Anderson PP series. Individual poles that can be keyed together. That is what I have on my pack for now.

Nuts & Volts
22 March 2012, 0835
Andersons are nice, but they sure are big. The PP series is a really good suggestion thou, cuz we use a couple of the 2-pole andersons that only have one contact in them. They are in a tight space and are a pain in the butt right now.

I like a bolted connections better for a motorcycle to safe space and lower contact resistance.

teddillard
09 March 2013, 1723
bumping an old thread... but here's where I am with this idea:

<iframe width="420" height="315" src="http://www.youtube.com/embed/TVAt4BwnJ4s" frameborder="0" allowfullscreen></iframe>

Hugues
09 March 2013, 2240
Wow, I'm repeating myself here, but one word comes to my mind when I look at this: craftmanship !

teddillard
10 March 2013, 0444
Thank you sir!

I took a bunch of snaps of the pack after a little change - I moved the connector up so that the receiving connector doesn't hang off the back, allowing a more compact mount. Also some detail shots of the brackets. Where you can see my, uh, "craftsmanship". :D Seriously. I can haz MILLING MACHINE? lol.

http://evmc2.files.wordpress.com/2013/03/dsc4032.jpg?w=1000&h=

http://evmc2.files.wordpress.com/2013/03/dsc4040.jpg?w=1000&h=

http://evmc2.files.wordpress.com/2013/03/dsc4043.jpg?w=1000&h=

More photos here: http://evmc2.wordpress.com/2013/03/10/battery-module-detail-shots/#

Red
10 March 2013, 0618
Ted, I like the concept, and as I read through your thoughts I kept thinking of how would a novice emoto rider handle swapping battery packs, considering complexity, weight, and convenience. Think 105 lb college girl. You are certainly on the right track though.

I read this morning that China recently has quietly proposed a carbon tax! The writer of the article (Gwynne Dyer) says that the Chinese have calculated they will lose 38% percent of food production when the global temps rise 2 degrees C in around 25 years.

teddillard
10 March 2013, 0637
That's something I've been trying to keep in mind. These packs would weigh about 10lbs each, so in that respect they're totally handleable. I've been thinking of adding a release lever- something that would cam the pack out of the Anderson connector by squeezing the handle. I'm not convinced I need it though...

Spaceweasel
10 March 2013, 1635
What about this sort of thing: http://www.aliexpress.com/store/product/ebike-battery-36V-10Ah-LiFePO4-Battery-packs/705561_688616156.html

Parallel them 2 at a time to get 72v 10ah. Already designed to fit on a rack.

teddillard
10 March 2013, 1739
uh, $2200 for a 40ah 72V pack of unknown C rate? I dunno... :D