Forum Discussion

mlts22's avatar
mlts22
Explorer II
Dec 22, 2014

Multiple inverters?

Would it help with maximizing battery power if one had multiple inverters for their rig?

One would be a 300 watt PSW like the Morningstar SureSine 300. This would be hooked up to an outlet or two and used for low-draw stuff, be it an electric razor, charging cordless power tool batteries, or other items.

Another would be a 2000 watt PSW inverter whose job would be to handle appliances like a Keurig coffee maker or other appliances which use a lot of juice, but have a relatively short duty cycle.

The advantage of having both is that the smaller inverter can always remain on (well, assuming it is being used), so its power overhead is a lot less. The larger one can be turned on/off when needed, as it has a larger (think 200 watts) overhead.

Think this would be a good way to go to maximize battery life when boondocking?

19 Replies

  • Lessee, I start the campfire and change channels with another log. Then I sit back and muse what kind of cocktail would be the ultimate for the evening. A Cuba Liebre? Surroundsound crickets, the distant braying of la burra, a crowing of a cockawhammy rooster who forgot to wind his watch. The crump and sigh of ocean waves, and a flit of whir as a bat wheels and darts.

    And I don't even have to reach for the remote to turn it all off before I arise and go inside. Seven new books to read on the Nook.

    I looked and I looked and I looked. Nothing. I'm going to have to call the manufacturer tomorrow and ask them where I plug in the French Press.

    But the pair of CREE reading lights work like a champ. 2.5 watts each. Forgive me but I forgot the name of the kind forum member who donated the 2 stainless steel swivel wall lamps to me. Rest assured they are worked to death at night!

    My novel "Jeepers! You would not believe the new space port! They are still riveting more plates of solid steel, and erecting sheets of asbestos to protect against blast damage! The Plutonians are getting like the Venusians - smoking cigarettes, always smoking!"

    I need 2015, and a hundred million "mandatory accessories" like I need another hole in my head. This laptop I'm typing on was an over the top purchase. Niner's Galaxy however is worth it's weight in diamonds. I called my Son In Law yesterday and while an outboard engine was roaring fifty feet away from him, I could hear and understand words!

    Damn! Where's the remote? I need to stir the campfire!
  • We have two but they are both big uns. A 2000 watt go power sine wave and a 3000 watt Samlex 3000 sine wave converter/inverter. Having said that we beta test for Samlex so we always have the latest greatest but because it is subject to unexpected removal and install we have to have one as backup. We find that both of them have very little current draw on idle. Frankly, unless you have a residential fridge and need a hot backup I wouldn't bother having a second inverter. Throw another solar panel on the roof instead.

    JMHO.
  • I agree, yes it would be good, and that's something I might do myself. My 2kw Samlex is using quite a bit overnight.
  • smkettner wrote:
    When the large inverter gave out on our big trip last summer we lost some usability but the small stuff was good to go.
    This would be the number one reason for me. If the big one broke you wouldn't be totally assed out.
  • The draw from my 1800w inverter would use noticeable power when inadvertently left at idle and seemed like a waste to charge a phone. Added 300w inverter and cut idle current by 80% for most uses. Large inverter powers the microwave circuit and one added outlet in the kitchen. Small inverter powers the remaining outlets on two convenience circuits. Works for me.

    When the large inverter gave out on our big trip last summer we lost some usability but the small stuff was good to go.

    On edit:
    I carry no generator so no inverter means no 120v power unless I plug in.
  • RoyB's avatar
    RoyB
    Explorer II
    All INVERTERS have a parasitic draw when just turned on and not drawing any power. This is about the same for a 600WATT PSW INVERTER and my 1500WATT PSW Inverter. If you are not plugging anything into them they only draw a small amount of current from the battery. In my case it doesn't allow me any savings in power consumption from my battery bank.

    I have the 600WATT PSW INVERTER for my home entertainment and bedside emergency drop cord receptacles coming from the 600WATT Inverter. This is left on all the time when I am camping. Even when I am at an electric site.

    I also have the 1500WATT PSW INVERTER that is my backup INVERTER and I sometime plug my trailer SHORE POWER CABLE into this unit to fire up my 120VAC receptacles around the trailer. Being only rated at 1500WATTS however I have to throw most of my circuit breakers to the OFF POSITION to keep from overloading the 1500WATT PSW Inverter...

    I'm sure others do it differently...

    Once you establish what you can run form your batteries and know when to re-charge them the next morning during breakfast then it all becomes second nature using what you got.

    I watch my DC VOLTMETER PANEL and make sure I am not dropping below the approximately 50% charge state of my battery bank during the day/night run. It if makes until 8AM the next morning and still reads around 12.0VDC then I am a happy camper. Now I can use my 2KW generator and recharge my battery bank back up to its 90% charge state and do it all over again for the next day/night off the batteries.

    Roy Ken
  • Hi mlts22,

    Most of us do exactly as you suggest. I have a 300 watt MSW that I use for small loads (the laptop and a heating pad for the bed). It is not hard wired. Running it flat out draw about 30 amps, which to some would not be a low load.

    Then I have my 3k Magnum hybrid for when I want to use the high draw appliances. It is hard wired. I have a choice of powering the whole RV with it, or just one outlet in the kitchen area. I have seen it draw 276 amps.

    Some day, if the MSW 300 watt fails I'll find a 300 watt PSW to replace it.

    I do carry a 1000 watt PSW as a back up for the Magnum. So far it has not been used.
  • Not sure if it helps or not
    But that is exactly my rigs configurations
    Works great for us
    MS Sure Sine 300 and a Prosine 2k watt unit
    The larger unit has way to high an idle current draw for my liking
    Only ever turn the larger unit on to use the Microwave
  • An even better way would be to ditch the Keurig and make your coffee in a camp percolator on the range top.

    The propane range uses NO electricity. And I would suggest that cobbling together multiple inverters, or running ANY inverters for any purpose is going to cut substantially the useable battery time available.

    If you are determined to use these things, then in theory, what you propose might be a good idea. At the same time, I'm not at all sure you wouldn't be better served just adding one or two more batteries to the battery bank. It depends on what devices you want to use.

About Technical Issues

Having RV issues? Connect with others who have been in your shoes.24,240 PostsLatest Activity: Apr 26, 2025