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chef
16 June 2013, 2300
The D&D on my bike protrudes from the faring so a good amount of air moves through it while the bike is moving. With the higher summer temps and sustained highway speeds, the motor gets prettu darn hot. I can't put my hand on it for more than a few seconds without getting burned. It needs better cooling in general, but for now I'm more concerned with the residual heat after the bike has been parked. The motor is hot and sits there with no air flowing across it, baking the batteries closest to it. I've been directing an external fan at the motor when I park it in the garage to help pull the heat away. It's a hassle and I can only do that at home. Any ideas on how to automatically cool the motor when the bike is off? The DC-DC is not powered when the ignition is off. My thoughts are:
1) Add a second DC-DC drawing a vampiric load all the time (boo) to power a fan.
or
2) Use a high voltage DC fan with a temperature cutoff circuit. This probably has some vampiric load too but shouldn't be as much.

teddillard
17 June 2013, 0535
edit: There are no stupid questions, just stupid answers... thus they get deleted lol.

EVcycle
17 June 2013, 0714
and Ted,,,, well never mind. :) :)

I have to do the same thing at the track, but I can do it between every round. I guess the best thing to do is get a small temp device to see if is really too hot

If it is cool by the time you leave work and it is not over hot, I would let it cool on it's own. I have this unit http://www.trailtech.net/tto_temperature.html on the bike that does not use any pack power.

I got the 10mm spark plug unit and strapped it to the outside in a spot that does not get much air so I know it is will be the most accurate.

I was informed that 300 deg F was the limit so I use 250 Deg F to be concerned.

So far just running at around town speed the highest was 120. I will be testing in a week or two so I can report back then.
I also have forced air on the brush side of the motor to help with heat.

yankee1919
17 June 2013, 0751
Hello Chef,

Well, if you run the piss off the machine what do you expect:o. Ok lets get some facts, motor size, voltage and anything unusual? Ride in the morning or evening?
Hate to sound like "common sense" guy but with some details maybe we can help.

Tony
Los Angeles

teddillard
17 June 2013, 0928
lol ED! But seriously - he's not asking how to cool it, he's asking how to power the cooling fan, right, chef? At least that's how I read it after I already posted about fans and stuffz...

I'm not sure there's any other way other than what you've suggested - a separately powered and switched 12V DC/DC powering the fan, or a "pack-voltage" fan. Of course, maybe a small solar panel with an equally small fan... that folds out when you park it. Oh, that has SO been done... :D

4574

Hugues
17 June 2013, 1124
just my two cents here (because i'll probably have the same problem),

how about spraying a small water mist on it ? my guess is that it would take less energy to run the small pump to produce the mist than running a fan, for an equivalent amount of heat removed. Water is so much better than air to remove heat.

That said, you don't want to screw up other things with the water droplets or steam....

just an idea...

Athlon
17 June 2013, 1159
Water spray was the solution I used to cool my air cooled motor when I drove from Italy to Dakar , normally the motor is air cooled but on the car I have a few liter of water and when is needed I just open a tap for a few second and some water is just poured onto the motor.

Anyway I think there is no need to cooling when parked , if the motor is not running temperature will for sure lower dow because there is no current so no more heat is added to the system

chef
17 June 2013, 1923
Spraying with water is creative. I'm a little concerned with oxidation though. It should evaporate pretty quickly, but even so doesn't any amount of contact with water allow for oxidation? Once or twice might be ok, but this would be a twice daily event.


Hello Chef,

Well, if you run the piss off the machine what do you expect:o. Ok lets get some facts, motor size, voltage and anything unusual? Ride in the morning or evening?
Hate to sound like "common sense" guy but with some details maybe we can help.

Tony
Los Angeles
It's a D&D Sepex ES-10E-33 (http://www.evdrives.com/product_p/mot-es-10e-33.htm) running at 85v nominal. It draws about 385A peak during hard acceleration. Highway cruising speeds sucks down anywhere from 6-12 kW. Rushing to get to work against a headwind draws ~12kW, but if I slow down a tad and don't have to fight the wind, that can drop to 6-8kW. I tend to average 120 Wh/mi on highway commutes which last 10-15 minutes. Morning temps are ok, but summer afternoons in TX sizzle.


lol ED! But seriously - he's not asking how to cool it, he's asking how to power the cooling fan, right, chef? At least that's how I read it after I already posted about fans and stuffz...
Yes mostly. I'd like the fan to be controlled automatically so I don't accidentally leave it on overnight and drain the battery. Probably not enough of a draw to do much damage, but if I accidentally left it on and went away for a few days or a week, that could be problematic. I need to figure out where to mount the fan to get optimal airflow through the bike.

A secondary concern is that the motor bakes the cells directly above it. The disparity in temperatures could cause premature wear to the hotter cells. Maybe I'm being paranoid, but having worked with batteries through the years I'm not taking anything for granted. These are chemical devices after all and temperature plays a big part in their lifespan.

Ken Will
18 June 2013, 0433
A secondary concern is that the motor bakes the cells directly above it. The disparity in temperatures could cause premature wear to the hotter cells. Maybe I'm being paranoid, but having worked with batteries through the years I'm not taking anything for granted. These are chemical devices after all and temperature plays a big part in their lifespan.

Can you put reflector sheet between the motor and batteries?

Athlon
18 June 2013, 0959
Maybe at the end the easyest , coolest way can be yust a small 12V solar panel and a 12V computer fan , lot of air , witout any battery issue.

You can also use some NiCd AA battery to store the energy from the solar panel , NiMh can be discharged all the way down and are self balancing so you can leave the panel to charge 10 NiCd AA size battery , when you park you turn on the fan and when the battery is empy the fan will stop. In this way you can use a much smaller solar panel.

Frank
28 August 2013, 0516
Evgizmo (Gizmoev?) installed a fan with a delay timer IIRC for his D&D, I run a small fan off the wall plug when at home to move air over the CE of the motor for 15-20 minutes I also have a small fan installed to move air over the controller heat sink and I run this for 5-10 minutes after arriving at the house when I remove my gear, get the charger going, etc.



Sent from my Nexus 7 using Tapatalk 2

Spoonman
30 January 2014, 0321
I speed read this thread so I may have missed something but is there any particular reason why you couldn't just use a bog standard automotive thermostat from your existing 12V line and to your proposed fan in whatever mounting/offboard arrangement you prefer?

*edit: right so I went ahead and read the first post again (facepalm)
-Relating to "vampiric" loads, your average automotive thermostat is a bimetalic strip based device so there's no quiescent load.
-Regarding the DC-DC, you could readily enough setup a parrallel, ignition independent supply through the thermostat such that it will be shut off and the fan with it, rather than just the fan (your ignition can of course still shutdown any drive related 12V ancilliaries).