Winter Battery Storage

Batteries naturally self-discharge while not in use. The rate at which this happens depends on battery type and ambient temperature – cold will slow the process down and heat will speed it up.

When storing your battery over the winter months, you need to minimize the degree of discharge in order to keep it in good working order. That’s because when batteries sit in a partially discharged state, the lead sulfate on the battery plates start to crystallize and harden. (This process is known as “plate sulfation”.) Once fully crystallized, that portion of the plate is no longer capable of generating power. Should too much plate area become crystallized, the battery may no longer be able to generate enough power for your RV needs come Spring.

Here are a few simple storage procedures you can follow that will extend the life of your battery:

1. Remove any corrosion using a mixture of baking soda and water, and then clean and dry the top of the battery. This will eliminate potential discharge paths.
2. Terminals can be cleaned with a wire brush to remove remaining traces of corrosion.
3. If the battery is being stored in a vehicle, disconnect it to avoid self-discharge due to parasitic loads such as clocks, ground faults, etc.
4. Fully charge your battery before putting it into storage.
5. If the battery has removable vent caps, check the electrolyte (battery fluid) level in each cell. If required, add distilled* water to bring the fluid level to just below the filler tube. CHARGE THE BATTERY PRIOR TO TOPPING UP THE ELECTROLYTE, otherwise electrolyte expansion during the charging process could cause the fluid to overflow. *using regular tap water may introduce contaminants that could cause internal corrosion and premature battery failure
6. Keep your battery above 75% state-of-charge at all times. Check state-of-charge every 90 days and recharge if necessary.
7. Store your battery in a cool, dry place with temperatures no lower than 32°F (0°C) and no higher than 80°F (27°C). Do not allow your battery to freeze and NEVER attempt to charge a frozen battery – the battery could explode!
8. Never leave a battery on trickle charge longer than 48 hours, or serious damage to the battery will occur.

How long a battery will last is dependent on a number of factors, including manufacturer, power capacity, usage level, operating conditions, etc. But taking the time to properly prepare your battery for storage and remembering to maintain its state of charge during the winter months will help ensure you obtain maximum possible service life from your battery.