Battery Purpose?

coondog-JAY

Senior Member
Joined
Apr 2, 2014
Posts
148
Location
SW Ontario
Does the battery serve a purpose if the trailer is always plugged into shore power?

I guess my main question is will the fridge still run if it is being towed but the battery isn't present? Does the battery need to be present for the fridge ignition or will it use 12v from the tow vehicle in lieu of??
 
you need a battery present when towing to power your break away switch by law

when camping if hooked up to shore power the battery doesn't do anything except get charged by the converter
 
I think the battery has to be connected for the fridge to run off shore power. Not 100% certain on that. I know it had to be connected on my old camper. Not sure about the new one. The battery needs to be connected for your break-away switch to engae the brakes.
To the main question, I think the fridge will run off the TV 12 volt system, but again, I don't believe your break-away switch will work.
 
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snip....... I guess my main question is will the fridge still run if it is being towed but the battery isn't present? Does the battery need to be present for the fridge ignition or will it use 12v from the tow vehicle in lieu of??
Good question, never tried it....., but your correct the fridge circuit board does require a 12V power source to function.

Bob
 
+1 to the above mentioned legal requirement for the breakaway brake switch; it requires the battery.

To the other question, I'm not entirely sure if the TV will run some of the systems in the trailer. My jack will run off the TV without a battery attached, but long ago, someone had mentioned that the wiring from the TV that supplies voltage to the trailer to recharge the battery in tow may not be up to the challenge of running anything substantial. The fridge would be adding voltage to that line, not a whole lot, but you never know, it could be enough to cause a problem in the tow vehicle.
 
I frequently run my fridge on shore power with no battery. I often remove the fuse linking the battery to the 12v system when charging the battery off the converter and am still able to run the fridge.

When running the fridge on propane the 12v system provides the power for the control unit, nothing more. On pop-ups, the smaller fridge units can be completely powered by a 12v battery, but that won't work for the larger hybrid units.

Hope that helps!
 
it will run off of the TV's 12volt when towing and the converters 12Volt when camping on shore power. It does not use the onboard trailer battery but as I said it is law that you have an operable battery onboard solely for the purpose of powering the break away switch
 
snip.....someone had mentioned that the wiring from the TV that supplies voltage to the trailer to recharge the battery in tow may not be up to the challenge of running anything substantial.....
Good point, because I believe there is only about 1-2 amps coming from the TV 7-pin connecter to the TT battery.

On Edit: My understanding is that the 7-pin connecter can supply a maintenance charge to the TT battery, but can't add an additional charge (wire size to small). But have had others state that it can charge the TT battery at a similar rate as the TV battery (?).

Also, on some vehicles the 12V power at the 7-pin is terminated when the ignition key is removed.

Bob
 
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Everything works on the Eagle when I pull the main fuse. As mentioned in an earlier post, I would leave it in should there be a 120VAC disruption in power and the battery charge controller starts up again, it could cause a spike in the low voltage circuit, without a battery as a buffer.

Just my thoughts,
Don
 

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