Hello I am new to the forum. I came here seeking help as most probably do. I can't find this specific problem anywhere else on the forum. I just purchased a 2012 Surveyor select by forest river. I got a great deal on it. The problem I am having is all the 12v stuff works great when connected to shore power, so I guess the converter is making good 12v power. However it will not charge my battery. Power at the leads at the battery measures 13.6 volts until I connect them to the battery then the voltage just shows the 12.5 in the battery. I have checked and cleaned the battery ground going to the frame on the tongue, as well as three more grounds found down the frame rail of the RV near the rear. The battery is a brand new interstate deep cycle. I have also checked all the fuses in the camper power box. I have ohm'd the grounds I could find to a clean spot on the frame to be sure they are properly grounded. Any thoughts on why the voltage drops as soon as the leads are connected to the battery? The slide out works good when connected to shore power so I know the converter is not just dying under load.
Travel trailer battery won't charge
- Thread starter MLGRV
- Start date
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Rene T
Site Team
MLGRV said:
Welcome to the forum. Someone will have an answer for you shortly.
I know nothing about batteries so this is a shot in the dark. I wonder if one of the cells in this new battery may be shorted out inside the battery. Is it a dry cell battery or a wet cell.
Gods Country
Well-known member
I'm not so sure what you are experiencing is a problem. 13.6V seems correct, and if the battery is charged 12ish also seems correct for a converter that stages the charging, so as not to boil the battery.
ETA: Your converter really isn't a charger, but trickle charges the battery and helps to maintain and keep your battery topped up.
ETA: Your converter really isn't a charger, but trickle charges the battery and helps to maintain and keep your battery topped up.
I understand what you are saying however, I put the new battery in one day let it sit overnight. The next day I unplugged the camper and then tried to run the slide out in but the battery wouldn't do it, I had to plug the camper back in, then it went in fine.
It actually takes days to fully charge the battery. The battery voltage should read about 12.8 volts when fully charged and the converter off. I do suspect that the wiring is inadequate or faulty between the converter and the battery. A battery disconnect switch should be installed and used whenever the trailer isn't connected to power or being used.
So does the converter normally drop the voltage to just a trickle charge once it senses the battery voltage? If that's the case then there has to be a separate charge circuit vs the 12 volt power out put from the converter to the 12v lights and slide out. Is that correct?
Gary RV_Wizard
Site Team
The converter/charger monitors the battery voltage and adjusts the rate of charge while keeping the voltage up, typically 13.6v. Some chargers are more sophisticated than others, but they all keep the voltage up.
If the battery drags the voltage down it is either defective or low on water in the cells. A flooded cell battery needs to have the electrolyte at least 1/8" above the top of the lead plates. Add distilled water if its not at that level. If ts a sealed battery, there is no way to check or add, so replacement is the only option. Double check the connections to the battery terminals - a high resistance connection looks like a bad battery to the charger.
If the battery drags the voltage down it is either defective or low on water in the cells. A flooded cell battery needs to have the electrolyte at least 1/8" above the top of the lead plates. Add distilled water if its not at that level. If ts a sealed battery, there is no way to check or add, so replacement is the only option. Double check the connections to the battery terminals - a high resistance connection looks like a bad battery to the charger.
Rene T
Site Team
lynnmor said:
Can they test each cell to make sure they're OK?
