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Keith avatar image

New Multiplus 2000 Inverter/charger fails while heating RV Water heater

My new inverter fails and starts continously while heating a RV Water Heating. Water heater is 120ac and 10 amps. BMV-712 says it's 1700watts, and current is 144amps. SOC is 94 percent when I I turned on my water heater SOC was 100% and Batteries we're at 13.30 charge

I have 2 Battleborn Lifepro4 batteries

Checked all my wiring and double checked.

I have only allowed it to shut down and start 4 times for fear of ruining it.

Multiplus-IIinverter current draw
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Check the voltage at the terminals of the inverter when the water heater is on. It may just be a bad connection or under sized wires to the inverter causing a low voltage reset. I run my water heater with only a 1500 watt inverter and the water heater is 1450 watts. Voltage drop for me is about .7 volts.

Chedrick, I checked and normal AC voltage and it is 120, and when I turn the water heater on drops to 117 volts. I do have 8awg to my service panel. Any other suggestions?

Sorry I was talking about checking the dc terminals not the ac terminals. With that high of a load voltage will drop from 13v to say 12.4-12.3 with 2/0 wire that I have. If your running smaller wire from the batteries to the inverter the drop in voltage will be more. If your running really small wire it can drop low enough to cause problems and stop working like you were asking about. It was just something to trouble shoot. As far as running it very long your only going to get an hour or a little more (if you have the 100AH batteries) before batteries are at the recommenced depth of discharge. I’m not sure if battle born says you can use 80 or 90% of capacity. Hope this helps

Chedrick, today I replaced my anode in the waterheater, and flushed it out the best I could with my RV pump and hose, probably not the best job but it's all I had to work with. Afterwards I fired it up and it stayed on longer without failing, however my state of charge went from 100% to 75% in less then 10 minutes, and voltage dropped in minutes also, which concerns me. But your thoughts on if it could be the water heater just drawing to much?


If anyone out there is familiar with my issues, please please let me know. I would like to depend on this more then I can. Suburban doesnt show any specs on this SW6DEL water heater, but its suppose to be 120 ac volts and 10 amps. If I am consuming 1750watts, something is wrong.


What model of batteries do you have? The 100Ah or the 50Ah ones?

Specs for the Suburban indicate a 1440 watt element. This will be near to maximum output for the inverter and with the efficiency losses from the inverter, the draw from the batteries will be greater. I would question whether you have sufficient battery storage and inverter power to reliably use this method to heat water routinely. What is your useable total battery capacity?

I have 200 amp battleborn barteries, with a 12v-2000 watt inverter. Seems like it should be plenty isn't it? The first response from Chedrick has a smaller inverter and is working

Chedrick, here is what I have at the batteries, my inverter and my panel. Batteries the volts are 12.77 inverter 12.28 and the DC wires at my service panel in the RV


You have good size wire at 2/0 and it’s not a voltage drop problem to the inverter. When you flushed the water heater did a lot of junk come out with the water? I’ve heard deposits building up on the heating element that can make them have a buzzing sound but never give problems working correctly worth checking I guess. Sorry to say but you only have 200Ah and it uses 144amps an hour so your only going to be able to run it for an hour or a little more before the batteries are at max depth of discharge.

well thank you Chedrick...I learn a little more each time I dig in....Thats the best part. My Anode rod was very corroded, so I imagine my heating element is pretty bad, I have not taken that out yet, but will after I order one. Thanks Again.

  • Chedrick, I have been in Canada traveling and still having issues. My water heater continues to just down my invertor. Same thing when I run just my AC. I hope you or some could let me know who to call for some problem solving. I am attaching some screen shots of my monitor when this happens, when it's on, and current state. Help!


Have you checked the voltage at the inverter with a multimeter when the water heater is on to see if it’s reading the same as the BMV? Other than that I’m not sure I can help you any farther. I have Victron SmartSolar and BMV but my inverter is of a different brand. Hope you figure this out and please post if you do. Good luck

Thank you Chedrick

6 Answers
Stefanie avatar image

The Multiplus 12/2000/80 is rated for a continuous output of 1600 Watt (@25°C). So that might explain the inverter fail with your load.

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blond2silver avatar image

If this is still and on-going issue, and aside from the system wiring, and specifications of your installed system components, I would suggest changing out the electric water heater element (not the anode rod), and replace with a 1000 watt element. Typically, RV water hearters come with a 1500 watt element.

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Svtti123 avatar image

Food for thought.

I also heated hot water with a inverter and a ac heating element at 1400 watts the inverter handled it fine but it was just to hard on the batteries if the sun wasn't shining. So I used a ac varible speed motor control to lower the wattage and that worked great by lowering the wattage to 300 watts with the speed control much much easier on battery. Solar panels easily handle that on a cloudy day. And i heat a tank of hot water every 3 hours. Sunny days i just crank the speed controller up to a point that batteries charge and i still get plenty of hot water.

The only thing i didnt like was my inverter has a 4 amp idle drain on batteries so all night i wasted to much power..... older inverter . Now i installed a 300 watt dc heating element and dont need inverter even on for hot water. I could have went with a bigger dc heating element and used a dc motor speed control but 300 watts @ 3 tanks of hot water a day is more than enough hot water for the 2 of us a day.

You have options and heating elements come in all kinds of watts ac or dc. Just have to decide what is best for you.


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tmartin000 avatar image

Thank you for this question. I will now abandon my desire to use a 2000w Victron unit and now go with a 3000w Victron. :)

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ostersea avatar image

I also think the problem is to smal inverter.


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nebulight avatar image

What size wire do you have on your batteries to the Multiplus?

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I am using 2/0 awg from the batteries to the Inverter.