Went to extend the slide today and only heard a click sound. Tried the generator and it won't start unless I start the engine. I am plugged into shore power at home (30 amp). I've check circuit breakers and fuse panel and all seems well. The inverter is sending 14v but when I check the volts at the disconnect switch I only get 7.4 volts. The batteries are worse at 1.9 volts. Two questions, why would there only be 7 volts at the switch but 14 at the inverter? Also, I thought if I was plugged into shore power that the coach would use that instead of house batteries for the slide and fridge etc.... A little lost here. The only thing I did recently was replace the ends of the starter battery cables. Everything seems ok there.

I'd disconnect your batteries and inspect them for damage, check the water levels and try charging them with a regular automotive charger.Worst case scenario is one or more of the batteries is ruined, and has formed a short circuit. This is bad because it will heat up the battery something fierce, and could cause rupture, making a big mess.It could also be something simple like a corroded terminal on the switch, or on a battery, not letting the full voltage through.

Thanks for the feedback. Clearly I do not fully understand how my RV house batteries are wired or charged. I did a little more testing. I can start the generator after starting the RV. When I test the voltage at the batteries with the gen running I get the 14 volts I expected but on 30 amp shore power I only get 7amps. My circuit breaker is a 50 amp model so I'm using a 30amp shore power adapter. Is it possible that what ever charges my batteries is only delivering 1/2 the power due to only using on 120v line when using 30 amp power? This would be very disappointing if the house batteries do not charge fully on 30 amp service.

flapbreaker wrote:Thanks for the feedback. Clearly I do not fully understand how my RV house batteries are wired or charged. I did a little more testing. I can start the generator after starting the RV. When I test the voltage at the batteries with the gen running I get the 14 volts I expected but on 30 amp shore power I only get 7amps. My circuit breaker is a 50 amp model so I'm using a 30amp shore power adapter. Is it possible that what ever charges my batteries is only delivering 1/2 the power due to only using on 120v line when using 30 amp power? This would be very disappointing if the house batteries do not charge fully on 30 amp service.No 1/2 output is not possible by using a 30 amp 120v supply. You posted that you are seeing "7 amps" at the battery when your RV is powered by shore power. I'm going to assume that you meant 7 volts. If you are using a meter and seeing 7 volts measuring across battery terminals, you have a battery problem. It may be that you had a charging problem previously, and that caused the battery to fail with a shorted cell.

Did some more checking. sorry for my confusing information. I realized earlier that I incorrectly measured my batteries. Since they are in parallel I did it wrong. Having said that, I have confirmed a voltage at the batteries of 11.4 wether I'm plugged into shore power or not. If I start the generator then I do get 14 volts and can open the slide out. So it appears that the converter may not be sending out a charge??? I'll go do some prodding around on that.

Sounds like the converter is not charging as you indicated but it may be the batteries are so discharged with a bad cell or shorted and the converter cannot keep up. I would remove the batteries and put a volt meter directly to the battery cables and get a reading. If you are seeing 13.8-14 + volts it is the batteries not the converter. Good luck.

Battery trouble - 7.4 volts to house batteries...

flapbreaker
Explorer
Apr 10, 2014
Thanks for the feedback. Clearly I do not fully understand how my RV house batteries are wired or charged. I did a little more testing. I can start the generator after starting the RV. When I test the voltage at the batteries with the gen running I get the 14 volts I expected but on 30 amp shore power I only get 7amps. My circuit breaker is a 50 amp model so I'm using a 30amp shore power adapter. Is it possible that what ever charges my batteries is only delivering 1/2 the power due to only using on 120v line when using 30 amp power? This would be very disappointing if the house batteries do not charge fully on 30 amp service.
GordonThree
Explorer
Apr 10, 2014
I'd disconnect your batteries and inspect them for damage, check the water levels and try charging them with a regular automotive charger.

Worst case scenario is one or more of the batteries is ruined, and has formed a short circuit. This is bad because it will heat up the battery something fierce, and could cause rupture, making a big mess.

It could also be something simple like a corroded terminal on the switch, or on a battery, not letting the full voltage through.

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Battery trouble - 7.4 volts to house batteries...

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