Same box separated chambers
Hi saptzae,
They could use separated chambers. The sensing AND the preprocessing of the voltages and temperature as you know is highly CRITICAL. The connectors used inside the same enviroment is a weak point. The harness (testability) another issue.
The failure of both batteries perhaps can be explained by the only thing common in both incidents. The battery itself. Heat and electrolyte leakage conpromising this circuitry not adequately located.