Monday, January 24, 2022


Ask Dave: Plugging in your RV at home

Answers to questions about RV Repair and Maintenance from RV expert Dave Solberg, author of the RV Handbook and the managing editor of the RV Repair Club. This column appears Monday through Saturday in the RV Travel and RV Daily Tips newsletters. (Sign up for an email reminder for each new issue if you do not already receive one.) Today Dave discusses plugging in your RV at home.

Dear Dave,
I keep my camper plugged into a 20-amp outlet when it is in the driveway. Before I leave on a camping trip, I attach a charger to be sure the camper battery is as charged as possible. Should I unplug the shore power while using the charger? —John

Dear John,
This is a common practice with RV owners during storage and when getting ready for an RV trip. Something I stress in my seminars and RV Repair Club live events is to have a qualified electrician install a dedicated line with circuit breaker for your rig.

Typically owners bring their rigs to the driveway and plug into an outlet either outside or inside and think nothing of it. What they don’t see is that most garage outlets are “ganged” or wired to other outlets. All of them are on a 10- to 15-amp circuit breaker. That means there could be a refrigerator, air compressor, or other appliances that are also drawing from that circuit and can overload it. Since you indicated it’s a 20-amp outlet, I hope it is dedicated to just that plug.

To better answer your question, I would like to know what kind of converter/charger your rig has. If it’s a conventional converter, it will sense the battery condition and put a 13.6-volt charge to the batteries until they reach 12.6 volts and then go to a maintenance charge of 13.2 volts. This will keep your batteries charged but not conditioned. That’s because sulfur coats the plates during discharge and needs to have a bulk or conditioning charge of approximately 14.4 volts to break up the sulfation.

What type of aftermarket charger are you using?

Another question is what type of aftermarket charger are you connecting just before using the camper? If it’s a traditional portable charger, then it’s doing nothing more than your standard on board converter and I would not even use it. If it does have a multistage charger, then I would shut off the main switch at the distribution center and just use that.

A product that I have been using for storage and getting ready to leave is BatteryMINDer®. It throws high impact waves into the system to break up sulfation, which means less gassing and water needed. You can find them here:

Two other things to throw out there is make sure you are not running the roof AC units and refrigerator on that 20-amp circuit. Know your amp draw, as each roof AC can draw up to 14 amps and the refrigerator 8 amps or more. Second, which has nothing to do with the amp draw and charging but is an issue with refrigerators. Make sure the unit is level in the driveway before cooling the absorption refrigerator down. If it’s out of level, it can ruin the cooling unit –  which is an article for another day.

Read more from Dave here

Dave Solberg worked at Winnebago for 15 years developing the dealer training program, as marketing manager, and conducting shows. As the owner of Passport Media Creations, Dave has developed several RV dealer training programs, the RV Safety Training program for The Recreation Vehicle Safety and Education Foundation, and the accredited RV Driving Safety program being conducted at rallies and shows around the country. Dave is a leading expert in the RV industry and author of the “RV Handbook” as well as the Managing Editor of the RV Repair Club.


BatteryMINDER on Amazon


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5 months ago

Dave –

The original question was
“I keep my camper plugged into a 20-amp outlet when it is in the driveway. Before I leave on a camping trip, I attach a charger to be sure the camper battery is as charged as possible. Should I unplug the shore power while using the charger?”
This is like saying “I have water bucket, and I use a small hose to keep it constantly full. I attach a big hose to fill it even more just before I need it. Should I remove the small hose when I attach the big one?”
I’m not sure what the writer thinks is happening. Seems to me that if the small hose keeps the bucket full to the brim, adding a big hose won’t fill it up any further.

5 months ago

Dedicated 20 amp line for RV.

Steve Comstock
5 months ago

Dave, I am a little puzzled by your answer. I read the original question to mean, “should the battery be isolated from the converter to use another charging source on it?” I have the same question, actually. Since I run my RV’s electrical system from a 20- or 30-amp home source, in order to charge the battery with my desulfating charger, it seems it should be necessary to isolate the battery from the converter to do so. I am interested in your answer.

5 months ago
Reply to  Steve Comstock

Same here, the original question was not addressed. I use a Victron Smart charger but I always disconnect shore power first, but as the original question refers to this I would like to know too.

5 months ago
Reply to  Brian

Dave did answer the question as well as he could without knowing what type of onboard system is installed.
Thanks Dave for your informative articles.

5 months ago

I’m anxious to see your article for another day about absorption refrigerators. Ours works when it feels like it. I’ll probably replace it with a 12 volt, just don’t know when.

Rock & Tina
5 months ago

If the converter installed in your RV is multi stage then the best answer is to just use shore power and no aftermarket charger.