Это из Q&A от производителя моих батарей (ampere time, батареи 12в с BMS):
Question:
Can these be safely connected to 48v system?
Answer:
"To connect batteries in series or /and parallel, batteries should meet the below conditions:
1. identical batteries with the same battery capacity (Ah) and BMS (A);
2. from the same brand (as lithium battery from different brands has their special BMS);
3. purchased in near time (within 3 months).
For the 48V system you mentioned, we recommend you could refer to the following connection: Connect 4* 12.8V100Ah battery in series you could get a 51.2V100Ah battery system with 100A BMS, which has a total energy of 5120Wh, supports max 100A continuous charging/discharging current and max continuous 5120W load power."