Last Updated on March 12, 2003
Written and compiled By Bill Darden (freely reproducible public domain)
Re-produced here by www.optimabattery.co.uk for your information, and it will be updated regularly.
Batteries naturally self discharge while in storage, and sulfation will begin occurring when the State-of-Charge is less than 100%. 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 tops of the batteries. If the battery is in a vehicle, remove the negative connection from the battery to eliminate the additional parasitic discharge.
13.2. Check the electrolyte levels and add distilled water as required, but avoid overfilling.
13.3. Fully charge and equalize, if required, using the procedures in Section 9.
13.4. Store in a cool dry place, but not so that it will freeze. The freezing point of a battery is determined by the State-of-Charge and the higher it is, the lower the freezing temperature. (Please see the State-of-Charge table in Section 4.) Based on the battery type you are using, connect a "smart," microprocessor based three stage or four stage charger, such as a Battery Tender, BatteryMinder, etc., or a voltage regulated float charger, such as a ChargeTek, etc., to continuously "float" charge your battery. Do not use a cheap, unregulated "trickle" charger or a manual two stage charger which was not designed for float charging or you will over charge your battery.
The following graph from Concorde demonstrates the effect of temperature on float voltage requirements.
TEMPERATURE IN DEGREES C (F)
[Source: Concorde]
13.5. A less desirable alternative to float charging would be to 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. The frequency of testing and recharging will depend on the ambient storage temperature.
13.6. When you remove the batteries from storage, equalize wet (flooded) or AGM batteries, if required, using the procedure in Section 9.
