I bought 7 of the BatteryHookup SPIM08HP packs and just wired the first of 5x 48 volt batteries with a 14s Heltec active balancer and a Daly BMS. When I assembled them the donor cells were not balanced with the 36 volt pack cells. On the first charge the Heltec balanced all the cells to within 2 millivolts. Each of the remaining 4 batteries will get their own Heltec and a 100A Daly dumb BMS. All 5 batteries for 12.5 kWh's will connect to a us bar so if one has a problem the others will continue to function. They will be charged with 6kW of solar and a 5KW inverter/charge controller. I'm very impressed with the capacity and power of these cells so far.