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[Reaper]

I've finally started building my EV and done some wiring.  Just when I think that I've got the hang of this thing, I go to http://www.electricmotorsport.com/store/ems_ev_parts_batteries_svr.php and find out that particular batteries are capable of delivering high voltage.  Wait a minute, I know batteries are CRUCIAL to the design, but I was under the impression that the only major factors that I had to deal with was whether or not they had enough amp hours, were light enough and were deep cycle.  Now I enter a new category... current delivery.

I was planning on using deep cycle marine batteries for the final run, but I have got a bunch of these batteries http://www.totalcomputing.net/index.asp?PageAction=VIEWPROD&ProdID=2038 on loan to test my circuit.  It's hard to beat free.  I am only trying to get the motor to spin with the throttle at this point.  I would only be activating the circuit for a matter of seconds at a time at best.

My question is, will I damage these batteries or the controller by using these low caliber batteries to test with?  I'd like not to return a bunch of busted batteries.

Thanks for all of the help.  I am finally on my way and I am thrilled about it.

[frodus]

just don't load the motor (disconnect mechanically from the chain/sprocket).... they're rated for a 1hr rate of 4.2A... not that much. They're UPS batteries, not meant for much of a load. I tested with a 18Ah Power Patrol battery when I first converted, Just make sure you're using the controller... don't just drive the motor with those batteries, they'll likely get ruined.

Just set the voltage cutoff higher than you normally would. If its just for a test, it should be ok, just don't do it for long, and don't BLIP the throttle, bring it on smoothly and slowly.

[frodus]

also, those 14Ah batteries aren't going to give you much range, how many are you doing?

[Reaper]

also, those 14Ah batteries aren't going to give you much range, how many are you doing?

Thanks for the response frodus.

I thought I would test with 4 of them.  Really what I am doing is more of a proof of concept.  Since I am using a brushless motor and a Sevcon controller I have to use the controller or the motor won't spin. 

(My boss is very interested in my recreational project for some reason and I'd like to show him some progress).  If the motor spins for 5 seconds, I think that would be more than enough.  In the end, I'll buy batteries that pack a bit more of a punch for certain.  Work donated these batteries to me to use as a test for free, so I thought that I would employ their use.

That brings up another question that I had in mind... since this is just a test, do I have to use 4 gauge wire still?  I am really not planning on heavy current draw.   Besides the heavy battery cable lugs would barely fit on those little things.

[frodus]

just don't beat the crap out of the batteries (suck a lot of current out of them) and you'll be fine with smaller gauge cable.