The 12 volt lead-acid battery for my backup sump pump does not seem to last for more than about one year. There is a “maintenance” battery charger that is, supposedly, designed to keep a battery topped off and ready to go should the backup power be needed.

I have heard the rumor putting batteries on the concrete floor will shorten their life. Research on the net suggests a few theories why this is or was true. Thoughts include:

• Batteries on cold concrete floors develop a thermal gradient with the plate near the floor slightly colder than the top. This creates a slightly different potential which can mess with the balance of that cell. The idea that backs up this claim is the notion that submarine batteries bubble air through their battery’s electrolyte liquid thereby maintaining flow of the liquid which stabilizes the liquid’s temperature via mixing.
• Battery housings use to be made of materials that conduct heat more thus making them more susceptible to the previous issue.

Perhaps I should use a flooded battery so I can top it off. Perhaps putting it on the shelf will make a difference. Then again, this battery and the one before it are from Wal-Mart.

Guess it is time to search out Solar Energy suppliers for their design guidance for systems that require batteries.