On Thursday, March 14, 2013 1:44:45 PM UTC-4, KenK wrote:
I use a deep-discharge battery for power for a light and a fan in the event of an A/C power failure. It looks like a car battery. Anyhow, after years of service, with a small charger, I've started having problems with charger to battery contact. The charger uses the usual claw-type clamp-on connecter. I've tried using one of those sleeve-with-a-wire-brush-inside cleaners to rotate on the battery terminals. Doesn't help for long. Every few days the charger light goes goes from green to red and I have to fiddle with the connections to the battery to resume trinkle-charging. Any suggestions on something to keep the connection working? Any way to clean the charger clamp on maybe? File it? Small problem but annoying. TIA -- "Where there's smoke there's toast!" Anon

Use a marine battery with wingnuts or a more modern car battery that has bolt holes and hardwire the charger. Or those battery terminal clamps that convert a regular battery to the new style.