Battery Chargers for Antique Cars and Off-Season Storage

Frequently Asked Questions about Off-Season Maintenance

What size charger should I use to maintain my battery?
For standard starting batteries, any one to three amp fully automatic charger will work fine. Starting batteries aren't designed for deep cycling, so they can't handle multiple discharges. Maybe three or four at the most.

Choosing a charger for a deep cycle battery depends on the amp hour of the battery, and whether you want to charge or just maintain the battery. The higher the amp hour of the battery, the more amps you'll need to charge it. For maintaining only, a lower amp charger will work (such as one in the 1-3 amp range).

This chart will help you choose the correct charging amps for many SLA and AGM rechargeable batteries:

You can estimate the charging times with the following formula:

To get the battery all the way to 100%, you'll need to approximately double the charging time from this formula.