that is kindof what I had in mind, I just picked up a HF kit off CL its only 45 w 3 panels of 15w each, I haven't opened it up yet but I assume each is 12v and they are supposed to be hooked up in parallel,
what I was going to try is take 2 panels and wire them in series for a nominal 24 v, but that would only be 30w max output, 1 amp shunts should handle it. question is what would be better? 8 lifepo4 at 3.6v which I consider full is 28.8v, it perfectly mimics the lead acid commonly used for this application, I think 14.4v is pretty common for a dump voltage, and I got 8 funky pouches leftover from my old pack no good for EV but something to tinker with, maybe a pack for my boy's 200w razor, at 20 ah, well whatever is left of it that is about 500w, those panels will never fully charge them, it would take like 15 hours, especially if they already have high resistance, but if they were full with 8 shunts fully on, 28.8w I honestly don't think those panels can push much more.
I also have a bunch of 18650 laptop cells I want to do something with, but those would add up to 32.8v full, unlikely those panels will ever fully charge a decent size pack, I wonder if I should use them, and those TC parts for LVC, what were the values? 3v I think on the instructions for lipo, what was the next one up? for I am mostly interested at a cell level to make sure one or the other doesn't get too far off, but granted this is just a small scale experiment, ultimately I am looking for a couple decent panels, there is an outfit locally that sells 230w at cost about $170, now those would push too much for the shunts to keep up, thing with solar can be disconnected unlike wind, not sure how those circuits operate but if it anything like the LVC, NO, maybe I can have it run a relay, I'm told a mosfet would be better, I honestly don't really know what a mosfet is, I read about it once, I need to go back on it, same on the lvc side it could disconnect the load to protect the batteries.
I am thinking if I go for lifepo4, on a larger scale, with 4x230w panels in series, and the Zephyr I already built, in theory I should be able to charge my 4kw pack in about the same time I do off the wall, ( without the charger, maybe its a bad idea), and it had been suggested to me out of the old pack scrap the bad cells and make it a 3kw, or I guess I could buy a few pouches, and have 2 packs, they are not that hard to swap.
so which one should I try, lifepo4 or lipo? that is the question, I know at some point there were some custom panels made, like 32 cell instead of 36 and while they would never overcharge a lead acid, they never did any good either, I am thinking a decent size 8s lipo will have a similar behavior on a standard panel, temporary manual balancing may be required, so I am inclined towards lifepo4 for an experiment but the cells I have are too large for these panels, maybe at say 6 hours a day X 30w, I should build a couple 200wh lipo a 4s? packs for the gokart, charge 1 a day, and manually balance them on the bottom? cell logs have an alarm don't they? save the Zephyr balancing board for a decent size setup?
but I am not smart enough to make a decision on my own