I'm planning to make an outdoor battery that doesn't need heating when charging at low temperatures in winter, some distance from the house for better fire safety. Yes I know with LFP handled properly the risk is minimal, but there are several adjacent houses in a row so any fire could spread to neighbors which might be very costly (not covered by insurance), not enough land for a separate garage to put batteries in.
I've just ordered 16pcs of 3.1V 230Ah Na-ion cells (it will take 2 months to ship from China as I couldn't find any EU stock yet), and found locally a hermetic outdoor battery box that fits 15S pack in 3 rows by 5 (or even 18S 3x6 but that would be too high voltage for typical 48V inverter). Na+ max charge voltage is higher than LFP so 15S should be a good match for typical 48V inverters. It's a compromise as it will never be discharged below 20-30%, so it's really about 150-170Ah usable capacity before the inverter shuts down at about 40V.
Does anyone have any recommendations for a good BMS to use with 15S Na-ion pack? I'm thinking about JK BMS PB2A16S20P v19 as I'm already familiar with it, used at another location (with 16S LFP and Deye 3.6K-SG03LP1-EU), with custom settings modified from LFP defaults to better match Na+ cells. Basically just protection and balancing, with the wider Na+ voltage range the SOC should be reasonably accurate based on voltage alone with no BMS-inverter communication. Does anyone here have better recommendations, or perhaps there are already BMS designed for Na+ available? (OK even if only from China, the BMS if ordered soon should arrive before the cells anyway.)
I've just ordered 16pcs of 3.1V 230Ah Na-ion cells (it will take 2 months to ship from China as I couldn't find any EU stock yet), and found locally a hermetic outdoor battery box that fits 15S pack in 3 rows by 5 (or even 18S 3x6 but that would be too high voltage for typical 48V inverter). Na+ max charge voltage is higher than LFP so 15S should be a good match for typical 48V inverters. It's a compromise as it will never be discharged below 20-30%, so it's really about 150-170Ah usable capacity before the inverter shuts down at about 40V.
Does anyone have any recommendations for a good BMS to use with 15S Na-ion pack? I'm thinking about JK BMS PB2A16S20P v19 as I'm already familiar with it, used at another location (with 16S LFP and Deye 3.6K-SG03LP1-EU), with custom settings modified from LFP defaults to better match Na+ cells. Basically just protection and balancing, with the wider Na+ voltage range the SOC should be reasonably accurate based on voltage alone with no BMS-inverter communication. Does anyone here have better recommendations, or perhaps there are already BMS designed for Na+ available? (OK even if only from China, the BMS if ordered soon should arrive before the cells anyway.)
