Friday, July 6, 2012

DC Charging

This afternoon I changed the profile of my stationary pack from 24 volts to 48 volts. This should allow lower current to do the same charge time. I connected and the PWM went from 93 PWM at 100 current amps at 24 volts to 52 PWM at 100 amps at 48 volts. I then had to lower the current as my tiny anderson connection could not handle 100 amps. The anderson connector got pretty hot to where you could not hold it. So I lowered the current to 50 charge amps. At 50 amps the car pumped in AH's at a pretty good clip and all the connections cooled down to where it was only warm to the touch. I will need heavier cables and an anderson or some other connector that can handle up to like 300 plus amps. The main connections can handle a bit of power. I do not think the inductor can handle that heat. I think I will need to increase the inductor to be able to handle 200 amps. I think that 200 amps will be plenty for fast DC charging. My stationary pack can handle that but my inductor is still getting warm.

So for now, 48 volts will charge up my 72 volt pack just fine at 50 amps. That is far better than my current charger and all that with no extra charger. Just a couple extra contractors and an inductor.

Cool, a small foot print controller and charger in one. Charge from multiple sources. DC stationary pack. AC directly from the wall. It may be possible to charge directly from a generator. Might need to convert it to DC then directly into the cars pack.

My setup testing is going well. It is a known way to charge. My testing is not new but its new for me. It will be new for all other users too but the ability has been built in from the beginning. Even the beta units could charge from a direct DC source. If you have a dumb charger you could connect directly from that DC source but you'd limit your amps to what that source can put out. But NO extra Charger. Just your Synkromotive controller and a couple contractors and inductors. Or you can use your motors field windings for your inductor. That will be tested once again with a bit higher voltage.

Pete :)

No comments:

Post a Comment