Dan, The ideal thing that comes to my mind and think that would be the most efficient is to use a custom dc-dc step-up power supply. This way you could use the energy stored from the solar battery bank from a wide input voltage range (lets say from 56v to 36v or even 24v) and boost it to your desired voltage. The big the current wanted, the bigger the power supply required.
This could even be a permanent connection that continous transfering the power from one bank to another, but if this is the case; then it means the two packs are inside the EV, right? If so, only a simple relay circuit for your solar Monrning star controller would be needed to switch the charge from one bank to another at several desired conditions. Since both packs are 48volts the solar system array would work fine for charging both. Other option is: two diodes (one Y diode) can be connected to each pack right from the solar controller, so it can charge both packs at the same time but one pack would not discharge the other (diodes would isolate each others battery) Just like the 'car isolator' a big diode works for ICE cars when they are equipped with big sound systems and use more than one 12v batteries. I have designed a small current step-up power supply that can provide up to 1.3amp output and up to 60vdc from a 12-24v source, that for a permanent connection would be a great slow charge solution. I could provide those designs if you want to. But is a very slow power transfering. I think bigger powerful solutions can be found on mouser.com, digikey.com etc. Marco Gaxiola Enviado desde mi iPhone > El 19/04/2014, a las 02:12 p.m., Dan Baker <[email protected]> escribió: > > Hello fellow Evlist users, > I have question around charging the battery pack on an EV from a larger > pack of batteries, same voltage. I'm looking to build a stationary solar > array (48v) and charging 12 x 12 volt 133 amp/hr sealed lead acid > batteries, 4 batteries per bank These are retired but gently used UPS > batteries and I will have about 1200 watts in solar going into a > Morningstar 45 amp solar controller. I would like to be able to charge my > EV boat pack (http://www.evalbum.com/4767) from this pack, UPS batteries > again, but 4 x 12 volt AGM 133 amp/hr. > My questions for the list: how do I transfer the charge from the solar > bank to the EV pack? Can I just use a charge cable directly and the two > banks will equalize? Or would I need to use a charge controller? I have > another 45 amp solar controller I could hook from the main battery pack to > the EV pack but I fear the input amps would exceed it? I remember a while > back someone mentioned they were charging a lawnmower from a truck pack, > wish I could find more info on this. > > Thanks in advance for your help and thanks for all the great contributors > on the list, fantastic learning and information! > Dan > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: > <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20140419/9a609d6a/attachment.htm> > _______________________________________________ > 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) > _______________________________________________ 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)
