The casual discussion of dealing with direct connection to the HV battery scares me a bit. I get that you're all DIY EV enthusiasts with experience dealing with high voltage, high power, but I'd highly recommend staying away from any direct connections to the HV battery. I like the idea of the low voltage "buffer" battery that then automatically connects to the on board charger. As mentioned, you could make it automated.
I'd recommend going with a higher voltage buffer battery, e.g. 48V (14s) Li-Ion, as 24-48V inverters tend to be more efficient (the lower the conversion ratio to 120V, the better, plus reduced I^2 * R losses in your cabling). You can use low cost pseudo-MPPT chargers like the MPT-7210A, for up to 600W of output power, and a boost type architecture, so your panels would operate around 20-30V as is standard, and the MPT-7210A would boost to 48V. I basically did this, though in a very roundabout way, for charging my Leaf, mostly as proof of concept. I had a 160W panel on my patio, charged a 1.8kWH Li-Ion 48V battery with the MPT-7210A, and used a 1.5kW inverter to charge the Leaf via the stock 120V charging cable. The battery got uncomfortably hot by the time it was depleted (it was made of recycled cells, which don't like discharging over 0.5C rate, and I was pushing it at nearly 1C). Here's a post about the solar/battery charger side, and a video about the battery/Leaf charging side if you want more info: https://secondlifestorage.com/showthread.php?tid=4161&pid=22926#pid22926 https://secondlifestorage.com/showthread.php?tid=4436&pid=27117#pid27117 https://www.youtube.com/watch?v=b3f68mS7IOk -- Sent from: http://electric-vehicle-discussion-list.413529.n4.nabble.com/ _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub ARCHIVE: http://www.evdl.org/archive/index.html INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)
