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Charge without BMS!!
#11
The only bms I would use with solar would be the chargery bms8. Its what I use, when the battery is full it will use a contactor/relay to disconnect the solar panel from the controller stopping the charge.

The cheap bms that use mosfet will produce voltage surges if they decide to stop the charge. Voltage surges will destroy anything connected to the battery.

I use this bms on my 4s lifepo4 but will easily work on a 3s li-ion , the cell voltage is fully programmable. I had it for the past year running 24/7 its proven very reliable in charging lithium. I also have an overvoltage protection relay as a "deadman switch" but that hasn't activated in months, the bms by itself does a good job. This bms is perfect when you want max performance of your system, I like fast charging my 220ah lifepo4, for that I have to set the bulk setting on my mppt to 15.5 volts, anything less and my battery will never reach 14.6 volts. When charging lithium you will find out if the bulk is set too low, you won't get max amps into the battery. You only have limited sunlight, so you need max amps when you can get it.

You can find the chargery bms8 100 amp model on ebay for about 95 dollars, for a 3s60 or 80p its worth the price. It doesnt come with the contactors but on my system I been using a 4 dollar 30 amp automotive relay, it works excellent since I never use more then 20 amps. You can buy 200 amp relays for less then 20 dollars.

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#12
1000w seem to be your max? IF so then at 3s IF we det max current to 1a per cell you would need.

1000/9v (minimum volt dictates max current)
111cells per pack. Ie you need 3s111p to be able to comfortable work with above setup.

So you bms should also cope with that. I would go with an bms that do Up to 150a internally or can run external contactor.
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