I have a 2004 5th wheel. It has two batteries. My problem is they keep going dead. I can hook up to shore power for hours and once I disconnect, they will only hold charge for a short time (they are practically brand new, I replaced the old ones because I thought they were bad, now not so sure). I run the generator and they die. I installed solar panels and they die. I’m guessing I have a short or some other problem and would like a suggestion on where to start looking. I really don’t want to take this to the shop, electrical problems can take sooo long to track down, especially @ &100/hr. If you have any ideas, I would appreciate your help.


I have two concerns about your problem with your RB batteries going dead.

1. Are batteries getting charged?

2. Is there indeed a battery drain in the system?

Since also have, the solar panel option for charging your RV batteries in addition to your 5th wheel converter your batteries should be getting an adequate charge. First lets check out your RV converter battery charging capability. To do this your solar panels will have to be disconnected from your batteries.

Then do the following:

Remove positive (+) and negative (-) cables from your “house” batteries. With your 5th wheel plugged into shore power take a voltage reading at the + and – cables. `(Solar panels also unhooked). You should get a reading of at least 13-13.5 volts. If your’re charging your Rv’s deep cycle batteries from a typical RV converter this is about as good as it gets. (Actually to bring your deep cycle batteries to 100% charge you need 14-14.5 volts in the bulk charge).

If your RV’s converter is putting out under 12 volts in the test your battery charges is no good. As I stated previously since you also have solar panels your batteries should be getting charged.

Is there a battery drain or electrical short in your 5th wheel?

1. Reconnect positive battery cable to your deep cycle batteries.

2. Connect a 12-volt test light, clamp end to battery post, probe end to battery cable.,br>

If test light lights up you have a drain. The brighter the light the greater the battery drain.

How to isolate shorts in 12-volt circuits.

1. Pull all 12 V fuses.

2. Reconnect test light – it should not light. If it light there is a short between batteries and 12 V fuse box.

3. If the above is negative, replace 12 V fuses one at a time and check systems with the 12 Volt test light each time you install a fuse. When the test light lights up you’ve found the faculty circuit.

4. Next, you continue trouble shooting to find the short in the circuit. Could be at an appliance or load (ex. light) or wiring itself but at least at this point you have your problem isolated.

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