How long will my battery last?
How long a battery will last depends hugely upon the way it is used and how well the battery is maintained. Both overcharging and undercharging will have serious adverse effects on the lifespan of a deep cycle battery.
In particular you can seriously shorten the lifespan of a battery if it is used in a deep cycle application that it was not designed for. An example of this would if you were to use an automotive starting battery as a deep cycle battery.
General expectations for batteries if deep cycled (these are just approximate guidelines):
- Starting battery (Automotive battery etc) : 3-13 months
- Marine Battery : 1-6 years
- AGM Deep cycle: 4-7 years
- Gel Cell Deep Cycle: 2-5 years
- Flooded Lead Acid Deep Cycle Battery (L16-RE etc): 4-8 years
The main things that you can do to ensure you get the maximum value out of your deep cycle batteries are to keep them maintained. This means keeping them watered to the appropriate level, trying to keep from discharging them more than 50% of their total capacity and having appropriate charging systems in place.
The charging is of special importance because both over and under charging will severely limit the life of your batteries, also if your batteries will see an extended period without being used you should ensure they are routinely checked, cleaned and fully charged before being stored. Also in some cases it can be a good idea to put your batteries on a maintenance charge over long periods of disuse.