Friday, December 9, 2022


RV Electricity – No~Shock~Zone by Mike Sokol – Issue 4


Issue 4 • February 25, 2018
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GFCIs: Do they save lives or just cause frustration?

Many of us have a love/hate relationship with GFCIs (Ground Fault Circuit Interrupters). That’s because while you probably understand that their job is to protect you from electrocution (death from electric shock), they can be a nuisance if they trip while you’re away from your RV and something important shuts down. For example, around 50% of you travel with pets. And if your RV air conditioner shuts down while you’re away for a day trip, your pet’s lives can be in jeopardy. But GFCIs do save lives and are required by modern National Electrical Code for all RVs. In Part I of GFCI theory I’m going to detail exactly how they work and how to test them. Then in a future article I’ll go over how to set up your RV’s power distribution to maximize electrical safety while minimizing nuisance tripping of your GFCIs. Read the full article here.

Let’s play safe out there… 


P.S. And just a quick note that this newsletter is made possible by the voluntary pledges of the readers of We could not bring this to you without their support. If you deem what we provide to you here and at to be of special value and would like to be a part of our effort, please consider pledging a voluntary subscription. More information is here. We will include you in special emails, articles and videos exclusively for our supporters.

Heat your RV with Electricity, not Propane!
SAVE $$$! Until now, the standard for heating recreation vehicles of all types has been to use bottled propane (LPG). With the CheapHeat™ system there’s a better option. Now you have a choice to change the central heating system between gas and electric with the flip of a switch. When you choose to run on electric heat rather than gas, your coach will be heated by the electricity provided by the RV park. Learn more.

Free Gear Contest

I’ve received a few Klein 11-in-1 screwdrivers for free giveaways. Solve this simple electricity equation and be the first one to answer it to win one for your tool kit.

If you have 120 volts AC, how many amperes of current are needed to produce 1,000 watts of power? Here’s an Ohm’s law chart if you need it. Yes, this is a real thing that we use everyday when working with electricity. And no, I do not have one tattooed on my arm. Click on it to see the chart full size.

The contest is now closed. We have two winners: Al Simons from Bass Harbor, ME  and Gary Stone from Federal Way, WA 

Truma AquaGo®: Instant, Constant and Endless Hot Water
trumalogoThe revolutionary Truma AquaGo® hybrid instant water heater provides instant, constant and endless hot water. The Truma AquaGo® is the only RV water heater that can be decalcified to extend product life and maintain performance. And its “Easy Drain Lever” makes winterization simple. Use the Truma AquaGo® to replace any 6 – 16 gallon water heater.  Find a dealer at

Industry Updates

Mastervolt has introduced the  MLI-E 12/1200, a drop-in Lithium-Ion battery for your RV house battery that doesn’t require a complete upgrade of your charging system. Here’s what they say about it:

“Efficient power in a compact case, ideal for automotive applications

“Lithium-ion technology has many advantages over lead-acid, allowing the MLI-E to save up to 70% in space and weight, recharge in less than an hour, and undergo 5000 deep cycles without damage – up to ten times longer than comparable lead-acid batteries. Moreover, the MLI-E uses exceptionally safe lithium iron phosphate (LiFePO4) technology.

“The MLI-E has an integrated battery management system including a safety disconnect, which protects it from deep discharging, overcharging and overheating. Eliminating the need for an external safety relay means the MLI-E is very easy to install. And thanks to its waterproof plastic case, the MLI-E is a straightforward replacement for most lead-acid batteries.”

I talked to a Mastervolt engineer earlier this week about their technology, and I’m convinced it’s the future of portable energy storage. Look for a complete article on this topic from me in the near future. In the meantime, read more about it hereMike

Survey Question
Have you been shocked by your RV? editor Chuck Woodbury and I ran our first survey together back in July of 2010, when we asked this question: “Have you or anyone who has traveled with you been shocked by your RV or another recreational vehicle?” This is what’s generally called “hot-skin voltage” by the RV industry. Here are the results:

  • Yes, seriously:  0.68% (7)
  • Yes, but not seriously:  21.10% (218)
  • No: 78.22% (808)

These results were alarming and what got me interested in writing for the RV industry. More than 1,100 readers responded in 2010, with nearly 22 percent reporting they had been shocked by their RV at some time, and a few of them reporting being seriously injured. If you need a quick refresher on what causes an RV hot-skin voltage, read this article.

Please take our new 2018 survey for comparison. That way we can see if we’re making progress educating the public about the causes and how to avoid hot-skin voltage.



Tools and Other Devices

Power meter
Staff writer Emily Woodbury brought this up in an earlier column, but I’ve used a Kill-A-Watt power meter for years to do a quick check of how much power an appliance is actually drawing. This version from YouThink has a bigger readout that’s easier to read. Power consumption of your appliances is a really important thing to know when boondocking, but is also valuable information for general energy management when plugged into shore power.

Last Month’s Posts

RV Electricity posts in last month’s RV Travel Newsletters:
Does ground size in extension cord matter?
RV Electricity odds and ends.
Can reversed polarity shock you?
Can a 9-volt battery start a fire in your RV?

Last month’s RV Daily Tips Newsletter RV Electricity Tip of the Day:
Care and feeding of your shore power connection – Part 1.
Care and feeding of your shore power connection – Part 2.

Last month’s survey results:







cord-753Don’t come up short!
Sometimes your 50-amp power cord is not quite long enough! That’s when this 15-foot extension cord will come in very handy. Sure, you can use a wimpy orange extension cord with an adapter — and risk burning up the cord, ruining appliances, or maybe even burn up your rig! With this cord along you’ll be all set. Learn more or order.

Q&A’s from Forums

I spend a lot of time on dozens of RV forums answering questions about electricity. Here’s a really interesting one:

From the Forest River Forum: Posted by DirtSquirt

I replaced the valve on my black water flush out system today and noticed that when I touched any metal part of the frame of my trailer, I could feel an electrical current running through it! Not enough to really shock me, but certainly enough to cause some discomfort. It doesn’t matter where on the frame I touch either, it feels the same. What is going on? I have a 2010 Rockwood Roo 23 RS.

A: Read my answer here. —Mike

Camco Store at
There isn’t much you need for your RV that Camco doesn’t have. If you think we’re kidding, then click through to the Camco store on Amazon where you’ll find some of their best-selling products — all for your RV or for you to make your RVing better. Click here and you’ll feel like a kid in a candy store.

Quick Tips

#7) Trailer Troubleshooting
Are your trailer’s running lights not running? Are your turn signals not turning you on? The first step to troubleshooting the problem is to test the 7-way connector on your tow vehicle for proper voltages. While you can use a meter to probe the connections, it’s much easier to use a dedicated tester with LED lights like this one from Curt Manufacturing. Just plug it in, have your significant other work the brakes, lights and turn signals, and watch the LEDs to be sure you’re sending the proper signals to your trailer.

#8) Be Safe and Seen
This may look a little silly at first, but all of my road crew keep a yellow safety vest in their vehicle and put them on whenever they have to step into traffic. You should have at least one of these to keep in your RV just in case you have to get out while you’re on a busy road to check a tire or flag down help. They fold up into a really tight package which can easily live in your glove compartment so they won’t be lost in the general mayhem. Being safe and seen is the latest fashion statement.  

The best book on RV electricity, hands down!
RV Travel contributor Mike Sokol is America’s leading expert on RV electricity. Mike has taken his 40+ years of experience to write this book about RV electricity that nearly anyone can understand. Covers the basics of Voltage, Amperage, Wattage and Grounding, with additional chapters on RV Hot-Skin testing, GFCI operation, portable generator hookups and troubleshooting RV electrical systems. This should be essential reading for all RVers. Learn more or order 

Easy way to add water to your batteries!
Never, ever, let your automotive or RV deep cycle batteries run out of water. Here’s a simple way to keep them topped off for maximum performance and long life. Just use this syringe with distilled water. So easy. Learn more or order.

My Other Life   

Many of you know that one day a week I teach live music production at  Shenandoah Conservatory in Winchester, VA. This week I’m working on the production of the musical Lysistrata Jones. Here’s a picture of some of my students down in the orchestra “pit,” named so because it’s an actual pit located below the stage. I put everyone in headphones, and my student Joey Lisco is in the center mixing headphones for the orchestra so they can hear what each other is playing along with cues from the music director. Not exactly the most glamorous job in theater, but a vitally important one. Imagine what your favorite musical would sound like without any music and you’ll get the idea. 

Road Signs by Mike Sokol

Planning For Failure
I often hear stories from the churches I teach at about worship leaders who won’t let the sound team “turn any knobs” on the mixing console. The leaders expect a great music mix to happen every week simply because it previously sounded great one time. Or perhaps there was one lucky service where none of the mics had any feedback. The assumption is that if there were no problems last week, there shouldn’t be any problems this week as long as the sound team doesn’t turn any knobs or push any buttons…

Read more.


Editor: Mike Sokol. publisher: Chuck Woodbury. Managing editor: Diane McGovern. Staff writer: Emily Woodbury.

Everything in this newsletter is true to the best of our knowledge. But we may occasionally get something wrong.  So always double check with your own technician, electrician or other professional first before undertaking projects that could involve danger if not done properly. Tips and/or comments in this newsletter are those of the authors and may not reflect the views of

Mail us at 9792 Edmonds Way, #265, Edmonds, WA 98020.

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Roger Spencer
4 years ago

Could you go over connecting AC ground & DC negative on travel trailers? Remember an article about it in the past, but have forgotten.
Thanks for the help!

Ron Richards
4 years ago

I looked on the specks for the mastervolt lithium battery and it said 90AH. How would that work while traveling with a residential fridge ? I’m looking at buying 2- 6 volts which would give me 250 AH. Wouldn’t that be better ?

4 years ago

Hi Mike,
Where can I buy the Mastervolt MLI-E 12/1200 in Canada? I have checked the supplier websites but they only give me a few suggested possible dealers. I can’t seem to actually locate any retail outlets.

Mike Sokol
4 years ago
Reply to  Bill

I’ll pass that on to my contact at the manufacturer and see what they say.

4 years ago
Reply to  Mike Sokol

Okay, thanks Mike.

Mike Sokol
4 years ago
Reply to  Bill

I’m talking to the head guy at MasterVolt on Friday. I’ll report back then.

Bill T
4 years ago
Reply to  Mike Sokol

Great. Thanks Mike. Looking forward to it.

4 years ago

Hey Mike- I live in Winchester and I’m about to embark on a solo multi- year RV Adventure. I could use a person consult. Is that an option? If so, let me know how to arrange it. Thanks

Mike Sokol
4 years ago
Reply to  Bonnie

Winchester, VA? Then that’s right down the road from me and I’m there at least once a week teaching at the University. Shoot me an email at to discuss.

4 years ago

how do I enter one of your contests?
answer to contest is 8.333333333amps

Mike Sokol
4 years ago
Reply to  pete

I’m now up to 140 answers since Sunday morning, 120 of which were correct. This contest/quiz was so popular that I’m going to install an external test program to track everything and give you immediate feedback about your entry. Stand by…

Jim Guld
4 years ago

In your other life, I see the bass player does all the real work. 🙂

4 years ago

Are you aware of a Kili-a-watt meter that would work with our 30 amp RV plug that would let me monitor how much power I use when connected to shore power when parked at home? All I have been able to find seem to be limited to 15 amp.

thanks for helping us keep safe.

4 years ago
Reply to  Mike Sokol

Put me on your wait list if you decide to start building them yourself.

William Fouste
4 years ago
Reply to  Gary

My EMS-PT30X RV Surge Protector gives a readout of amps that are being used in my RV. This is part of its scrolling information display.

4 years ago

The basic calculation results in amps. In a camping (or any) situation, long underrated extensions and/or poor connections to run that toaster or hair dryer could be a consideration at point of end use.

Andrew Messinger
4 years ago

Saw the piece on the Mastervolt MLI-E 12/1200. I use Lithium batteries in a number of applications and in my use they seem susceptible to cold temperatures which degrades output or in some cases simply makes them unusable. Is this the case with the batteries designed for RV use as well?

4 years ago

Hi Mike,

Great question…… My answer is xxx Amps (removed by editor so others can guess without having the answer right here).

I do enjoy your articles and I always learn from your writings. I am a DYI guy. Also if I am thinking wrong please let me know the answer. I hope I win one of the screw drivers.


Bob Ketchersid, New Jersey