Changing from 12 V to 6 V batteries

[02Corvette]

I have a 2018 Thor Quantum 31 ft that came with 12V batteries. I've replaced both coach batteries at the 2 year point because they were bad and originals just don't last. After talking with many people, all suggested I go to 2, 6V batteries because they last much longer.

Here's my problem...After connecting all the ground wires, (2 that I've found), to a bus bar and all the positive wires, to another bus bar, everything works off 12V's. When I plug into 110 power, I get nothing. The volt meter shows 12.5V, but will not power on the microwave or anything else. With the motor running, the motorhome is charging at 13.7, (plus), which should be good.

Prior to changing the batteries, everything was working properly, except the 12V batteries wouldn't last. I've been told the new refrigerators that run off 12V do draw a lot of power.

Anyone have any suggestions on where to start on why I have no 110 power? All circuit breakers are good, even the hidden breaker under the bed isn't tripped. House breaker is good also.

Thank you for any constructive suggestions/recommendations.

Ken

[Chance]

Originally Posted by 02Corvette

.....cut....

Prior to changing the batteries, everything was working properly, except the 12V batteries wouldn't last. I've been told the new refrigerators that run off 12V do draw a lot of power.

.....cut.....

What kind of “new” refrigerator are you talking about? Unless you replaced the refrigerator very recently with a new 12-Volt compressor refrigerator (which are very efficient), you should not run an absorption refrigerator on 12V because they will drain your batteries down at roughly +/- 25 Amps or higher. Yeah, very rapidly.

Or are you talking about having a residential 110V refrigerator powered by a 12V inverter? It’s not clear (to me anyway) what you’re describing. It’s very unlikely you have a true 12V refrigerator unless it was a recent upgrade.

Chances are very high you missed wired something on the 12V side, but in case you’re referring to a residential refrigerator powered by an inverter, that introduces other variables for things to have gone wrong.

I suggest you share a little more information about your motorhome, like model, refrigerator type, whether you have an inverter to run it, etc.



P.S. — It’s also difficult to follow what you’re stating by:

“The volt meter shows 12.5V, but will not power on the microwave or anything else.”

Are you powering microwave from batteries? Or are you saying microwave doesn’t get 110V power from shore connection even though converter (battery charger) seems to be getting power?

[02Corvette]

The fridge came with the M/H when purchased new and isn't my question. The fridge works as designed. An RV dealer told me the new models use more power, which drain the batteries at a faster rate.

I tapped all positive wires together so I wouldn't miss wire them when connecting back to the batteries. Same with the ground wires. Apparently, I still miss wired a wire because I have no power when I plug into my house, 110V.

I don't think there are schematic's for m/h's with all the electronics that are available today. I may have to trace each wire and find out what they connect to and then mark them accordingly, + /-.

[nosticks]

Do you know for sure that you have 110v at the source (where you plugged in).

[Travelin' Texans]

If you wired the the batteries the same as the 12 volt you're only getting 6 volts.
A pair of 12 volts are wired parallel, positive to positive negative to negative. The 6 volts are wired in series, positive to negative with one battery positive to the buss & the other battery negative to ground.

[02Corvette]

I'll recheck that today.

[02Corvette]

nosticks, I will recheck the house power today.

Thanks

[02Corvette]

I have 2 6 volts and wired for 12V.

Thanks, TT

[Travelin' Texans]

Originally Posted by 02Corvette

I have 2 6 volts and wired for 12V.

Thanks, TT

That'll do it!!!
Your welcome!

[Jusjay]

I went from 2 12v which were shot the day I pick up my RV to 4 6v... wired for 12v. I just added a 2000w inverter and rerouted all plugs except frig, microwave and AC to run on the inverter. Next on my list is portable solar. I dry camp a lot and this has been well worth the cost of the upgrade.

[02Corvette]

It turned out to be operator error. All the breakers in the panel were turned off. I looked at them and thought they were all in the on position. Problem solved with the flip of a few breakers, everything works as designed.

Thank you for the responses and suggestions.


Ken

[16ACE27]

Originally Posted by 02Corvette

It turned out to be operator error. All the breakers in the panel were turned off. I looked at them and thought they were all in the on position. Problem solved with the flip of a few breakers, everything works as designed.

Thank you for the responses and suggestions.


Ken

How did that happen if you didn't do it?

[02Corvette]

I shut them all off prior to replacing the batteries just to be safe, didn't want to fry anything. Dumb mistake on my part.

[Chance]

Originally Posted by 02Corvette

The fridge came with the M/H when purchased new and isn't my question. The fridge works as designed. An RV dealer told me the new models use more power, which drain the batteries at a faster rate.

I tapped all positive wires together so I wouldn't miss wire them when connecting back to the batteries. Same with the ground wires. Apparently, I still miss wired a wire because I have no power when I plug into my house, 110V.

I don't think there are schematic's for m/h's with all the electronics that are available today. I may have to trace each wire and find out what they connect to and then mark them accordingly, + /-.

I’ll probably regret this, but here it goes.

Now that you’ve solved your most urgent problem, you should look very closely at why you had problems in the first place that led to your two batteries’ early failure. No doubt inferior quality batteries didn’t help, but simply switching from 12V to 6V isn’t much of an improvement in itself.

I looked at archived Quantum motorhome specs for 2018, and it shows that all 31-foot floor-plans use residential refrigerators. That means it can not operate from propane, which means it has to operate from batteries when not on shore power or generator is running.

Specifications also show that the motorhome comes with a tray with room for 4 batteries, most likely because typical residential refrigerators require more energy than two normal-size lead batteries (whether flooded or AGM, or 6V or 12V) can support for longer periods. If you’re going to camp without shore power, and don’t want to run generator often, you may want to ask around to see how many RVers power their residential refrigerators successfully with only two batteries. I’d guess most have 4 batteries.

If Thor specs are wrong and you don’t have a residential refrigerator, please ignore this suggestion.

[sgtapd110]

Can I ask what 6 volt batteries you installed ?

[carlgorski]

Originally Posted by 02Corvette

I have a 2018 Thor Quantum 31 ft that came with 12V batteries. I've replaced both coach batteries at the 2 year point because they were bad and originals just don't last. After talking with many people, all suggested I go to 2, 6V batteries because they last much longer.

Here's my problem...After connecting all the ground wires, (2 that I've found), to a bus bar and all the positive wires, to another bus bar, everything works off 12V's. When I plug into 110 power, I get nothing. The volt meter shows 12.5V, but will not power on the microwave or anything else. With the motor running, the motorhome is charging at 13.7, (plus), which should be good.

Prior to changing the batteries, everything was working properly, except the 12V batteries wouldn't last. I've been told the new refrigerators that run off 12V do draw a lot of power.

Anyone have any suggestions on where to start on why I have no 110 power? All circuit breakers are good, even the hidden breaker under the bed isn't tripped. House breaker is good also.

Thank you for any constructive suggestions/recommendations.

Ken

I think you misfired. Check wires real close as possible. In future take a picture of hook up before. has to be wire to inviter cross over. when it senses shore power switches. that should be a positive.

[Jusjay]

Lifelines AGM 6V

[Tacouser]

I have a Thor 31W that came with a residential fridge. It came with two 12 volt batteries. I installed solar on the roof and changed out the batteries with 2-6volt 300ah batteries. It will run the fridge all night as long as I dont open and close the door every 10 min.