Evaluate a fully charged battery if one of the batteries is not installed correctly. Four fully charged single cells of the same brand, type, size and service life are connected in series, one of which is reversed. The resulting module is connected through a 1 Ω resistor until the vent opens or until the temperature of the reverse battery returns to ambient temperature. Alternatively, a stable DC power supply can be used to simulate the conditions applied to the reverse battery.
Result: no fire, no explosion.