Another battery question

[tooth ferry]

2 12 volt batteries. Checked batteries today for first time in about 6 months. 2 cells in one battery showed low (12.2) all other cells showed about 13.5. Trailer has been plugged in to 110 for 3 days which I normally do every 3 weeks or so. Added water even though it didn't look very low to me. Disconnected wiring and cleaned terminals and reconnected and added dielectric grease. The terminal where the 2 low reading cells were had some moderate corrosion but the others had none. Serviceman told me 6 months ago it could be leaking around one terminal but I never saw any water on the battery and the post did not feel loose. Letting it charge for 24 hrs and will check again. If the 2 cells are still low should I take that battery out of the system to prevent further problems.. Maybe time for 2 - 6 volts but what do you do if one of them goes bad and you aren't in a place to get a replacement?

[AZ Traveler]

Tooth,

Better solution is four 6 volt batteries.

[rohrmann]

Originally Posted by tooth ferry

2 12 volt batteries. Checked batteries today for first time in about 6 months. 2 cells in one battery showed low (12.2) all other cells showed about 13.5. Trailer has been plugged in to 110 for 3 days which I normally do every 3 weeks or so. Added water even though it didn't look very low to me. Disconnected wiring and cleaned terminals and reconnected and added dielectric grease. The terminal where the 2 low reading cells were had some moderate corrosion but the others had none. Serviceman told me 6 months ago it could be leaking around one terminal but I never saw any water on the battery and the post did not feel loose. Letting it charge for 24 hrs and will check again. If the 2 cells are still low should I take that battery out of the system to prevent further problems.. Maybe time for 2 - 6 volts but what do you do if one of them goes bad and you aren't in a place to get a replacement?

How were you able to get 12.2 or 13.5 volts on any one cell in a battery? I'm pretty sure, not with a volt meter. If you were using a hydrometer, did you test before or after adding water? If after, you would not get an accurate reading, and probably before it would not be accurate if the cell was needing water.

[The Bone]

Take your batteries ya both of them and have them load tested. Auto Zone will do it for free. As a matter of fact most if not all do it for free. I like to go where they are likely to sell a lot of batteries that way you have a better chance of getting a fresh one.