13. HOW CAN I STORE BATTERIES?
Batteries naturally self discharge while in storage, and sulfation will begin occurring when the state-of-charge is 80% or less. Please see Section 16 for more information on sulfation. Cold will slow the process down and heat will speed it up. Here are six simple steps to store your batteries that will protect them from sulfation and premature failure.
13.1. Physically inspect for damaged cases, remove any corrosion, and clean the batteries.
13.2. Check the electrolyte levels and add distilled water as required, but avoid overfilling.
13.3. Fully charge or equalize [controlled overcharge to equalize the voltage and specific gravity in each cell] the batteries.
13.4. Store them in a cool dry place, but not below 32o F (0o C). Depending on the ambient temperature, periodically test the state-of-charge using the procedure in Section 4. When it is 80% or below, recharge using the procedures in Section 9, with an automatic [voltage regulated] charger.
13.5. An alternative would be to connect an automatic [voltage regulated] "trickle" charger to batteries using 13.8 volts and equalize the batteries every couple on months. An automatic charger will keep you from overcharging the batteries.
13.6. Equalize only wet (flooded) or AGM batteries when you remove the batteries from storage, using the procedure in Section 9.