Gel batteries can be stored in sub-freezing temperatures as low as -25°F without freezing as long as they are fully charged prior to storage. The self-discharge rate of fully-charged batteries is so low in these conditions that they will not require charging for many months; however, if your gel batteries are frozen … they will not always recover.

To attempt recovery the following is the best plan of action:

1) Bring them inside and let them sit at room temperature for two days. (They must reach 60°F).
2) Charge the batteries normally. (Follow standard safety procedures).
3) Run a capacity check either through a quality discharge tester or by operating your power wheelchair in a controlled environment.
4) If you don’t get enough run time then repeat steps 2 and 3.