Electric Motor Werks actually says you can do this with their charger (http://emotorwerks.com/tech/electronics):
"Both non-PFC and PFC units can be used to charge your battery from a DC source. This feature can be used to charge one EV from another, to use the charger with a separate rectifier (e.g., for 3-phase operation), charger your EV from your solar array / stationary battery, etc. Non-PFC units can be used with DC input above the voltage of the battery being charged (up to ~400 VDC) PFC units can be used with any DC source ~100-400VDC." Anyone have experience with EMW chargers? I'm considering one, because my current (hah!) charging method is to charge five batteries at a time with a 40V/40A lab power supply. That means five days for a full charge of my 24 batteries. :-( Jan > Note that MANY switching power supplies can be run from DC. This means the > best way to charge from another EV MAY be through your charger. > > If your charger has a "universal" AC input, such as "110 VAC to 240 VAC," > then chances are that the first thing the line sees is a bridge rectifier, > which changes AC into DC. The rectifier will "commutate" your DC in the > proper direction, so you don't even need to worry about polarity. Most modern > chargers are over 95% efficient. > > So, the BEST way to assure you get the proper charge for your batteries from > another EV might be to connect your AC charger to the other EV's battery pack > -- assuming it doesn't go over the peak voltage that the AC line would supply > to it. (Generally, 240 * 1.414, or about 340 VDC.) > > You probably cannot do this with a charger that has a voltage selection > switch that lets it operate on either 120 VAC or 240 VAC. That implies that > there may be transformer or other AC-specific component in there. And the > charging current available may be reduced by 50%, since only half the input > bridge rectifier is being used. > > (If you think you may be doing this often, and have the proper skills and > documentation, you might bypass the input bridge entirely to get back the > full charging current capability.) > > Kids, don't try this at home! Unless you're skilled at electronics and have a > schematic, the next step would be to contact your charger's manufacturer to > see if they think this is a good idea! (And for liability reasons, they > likely won't. See if you can talk to one of their engineers, not a sales > droid. And see if you can wrangle schematics out of them.) > :::: Given an infinite source of energy, population growth still produces an inescapable problem. The problem of the acquisition of energy is replaced by the problem of its dissipation. -- Garrett Hardin :::: Jan Steinman, EcoReality Co-op :::: _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
