brand new battery 12.7 v..not getting power to the coach

[shanedank187]

used a volt tester the battery is brand new and fully charged, but for some reason, its not powering the rv, when i installed the new battery, went camping, turned on a few lights, instantly the lights shut off, when i had one on it was ok, put 2 on it would kill all the power, the weird thing is, when the lights came back on they were bright, not dull, also when i plug the rv into power or generator its fine. what could this be??

[MEXICOWANDERER]

Sounds like a baaaaaaaaaaaaaaaad connection. Start right at the battery. Do not be fooled by "new" looking connections, you have a loose or corroded one somewhere. The negative "ground" connection is infamous for causing this symptom.

Plugging in you create an alternate BATTERY complete with ground.

Your battery has a bad connection. Go for it.

[MNtundraRet]

The battery(s) ground on the "NEG" post of the battery. Did you remember to re-attach the grounding wire?

If you grounded the "POS" post you re-installed the battery(s) back-words. It may blow the fuse on the converter/charger if left that way.

If two 12v batteries, are they connected in parallel? Two 6v volts must be in series.

[Simplygib]

You said...."when the lights came back on they were bright, not dull..." How is it that they come back on? Did you reset a breaker, or do they come back on by themselves after you turn off the extra lights? I suspect a loose connection somewhere if it's the latter. Make sure battery terminals are clean, free of corrosion and connections are tight.

[tenbear]

did you hook up the battery with the polarity reversed? do you have a battery disconnect switch that is off?