Battery Tenders

[tboltmike]

This battery maintenance device I have has a LED that changes from red (charging) to green (maintenance). I will go days on red before changing to green even if the leads are removed just for a few minutes. Even if green it seems to evaporate about 1/2 of water from the battery in a couple of weeks.

Does this indicate that I have a battery problem or is this normal? The battery performs well in that it readily cranks fires the engine.

Thanks, Mike

 

[bruceb58]

Re: Battery Tenders

Sounds like the battery may be bad. The battery tender goes to maintenance mode once the battery gets up to a predetermined volatge which is the volatge of a fully charged battery. If the battery has a bad cell, this voltage will never be reached so the battery tender will continue pumping in its normal charge current current to try to get it there. In the process, you will boil the water out of the cells.

It is possible that the battery tender is not switching to its maintenance mode beciase it is faulty. I would do this...take the battery tender off and let the battery sit for an hour. A fully charged battery will be at around 12.6V. If the battery is at this voltage, the battery tender may be bad.