Small portable inverter to save electricity

[Jerry Dixon]

Is there any battery saving advantage to using a small portable inverter plugged into a 12 volt receptacle in an RV?

[ependydad]

Versus what?

[Jerry Dixon]

Versus using the RV's built-in inverter. I hear it drains batteries 10 times faster than using 12 volt appliances.

[TURBS]

What are you going to plug into it?

[A32Deuce]

It all depends on the load as to how much it draws.

[dontay]

We carry a 400w Xantrex inverter. Use it for charging small 110V only things like shaver, tooth brush, camera, etc. It draws about 1-2 amps with no load. The 1500w built-in Xantrex in our old motorhome drew about 7-8 amps with no load.
Plus I can carry it in the Jeep to recharge the camera, etc. during the day and on trails.

[AquaMan]

I don't know about 10x faster, but there is a loss factor when using an inverter. Most are around 80% efficient, meaning there is a 20% loss. Larger inverters usually have a fan also that has additional draw.

[TURBS]

Am I wrong in thinking that it really doesn't matter if you have a 1000 watt inverter or a 5000 watt inverter if you plug the same thing into either it's going to draw the same?

[doc73]

I would have thought, but the poster a few up said they knocked a few static amps off by using a smaller inverter..

[TURBS]

Originally Posted by doc73

I would have thought, but the poster a few up said they knocked a few static amps off by using a smaller inverter..

Sounds reasonable.

[Skyliner]

I'd check the no load draw on the inverter. My 1500 watt Samlex pure sine wave inverter draws about 3/4 amp with no load.

[Jerry Dixon]

I am thinking about getting one of these and wondering if it will draw less from the battery opposed to using the built-in inverter. Amazon.com : BESTEK 300W Dual 110V AC Outlets Power Inverter Car DC 12V to 110V AC Car Inverter with 3.1A Max Dual USB Charging Ports for Smartphones, Tablets and More : Vehicle Power Inverters : Car Electronics

[pdqparalegal1]

I have a small inverter plugged into the antenna booster to plug a flat screen TV into at rest ares to watch over the air TV. No problems so far, but it's short term.

[A32Deuce]

That TV plug has bigger wire feeding than the 12 volt outlet in the dash. Use one of them to run your inverter.

[Kaadk]

If you can, I'd skip the inverter all together. Turbs post before was right that the appliance will have the same draw, no matter what it's plugged into, so the only thing you can do is mitigate the amount of loss that comes from doing too many conversions. To charge a cell phone, in most cases you can go:

12V DC -> AC -> 120V AC -> DC -> 5V DC (using an inverter)

or:

12V DC -> 5V DC (using a cigarette lighter style USB adapter like this)

which route would lead to more loss?

So, first look at what you actually need AC for. Then, whether or not you can replace those with AC less appliances. For example, somebody mentioned a shaver. I replaced my plug in shaver with battery powered one that runs on Double AAs (Like this).

Then, if you still really, really need an inverter. In theory, a smaller inverter might be more efficient. Or it might not. Smaller often means cheaper often means more cutting corners... so it's also possible that the smaller inverter can cause a higher percentage of loss than the larger inverter, if it was more cheaply made.

[Bushbunch]

Square wave AC, am I correct? Some motors will not run on square wave AC.

[doc73]

Sine wave is better. Modified Sine wave are the cheaper units generally

Sent from my SAMSUNG-SM-G870A using Tapatalk

[the old geezer]

Originally Posted by dontay

We carry a 400w Xantrex inverter. Use it for charging small 110V only things like shaver, tooth brush, camera, etc. It draws about 1-2 amps with no load. The 1500w built-in Xantrex in our old motorhome drew about 7-8 amps with no load.
Plus I can carry it in the Jeep to recharge the camera, etc. during the day and on trails.

if you are plugging in a 110v charger to an inverter to charge tooth brush cameras etc you are wasting energy, use a 12v adapter direct to the small appliance. I think that is what the op was trying to find out.
A friend of mine uses an invertor from the 12v power point, then plugs his phone charger into it, but the phone could be plugged directly into the 12 volt with the correct connector.

[frugalbk]

A lesson learned the hard way. Plugged a higher voltage appliance into my 750 watt inverter plugged into my dash 12volt receptacle. It didn't trip the inverter's circuit breaker but pulled enough amps through to blow the fuse for the 12volt receptacle. Checked all the fuse panels couldn't determine which fuse was blown. FR documentation actually was incorrect. Finally found out from repair shop that there is an in-line fuse on the dash 12volt receptacle, only 7.5 amp. Switched to 15 amp now. Cost $$ me to have the shop technician to diagnose.

[Skyliner]

I would not waste my money on a modified sine wave inverter. I actually destroyed a laptop by using a MSW inverter. I've also found that you may experience noise when using MSW inverter on TVs and DVD players.

You can get a decent pure sine wave inverter at a reasonable price. I'm partial to the Samlex brand because I"m on my 3rd PSW inverter with them and they all ran great in my last 2 campers. My only regret with purchase is selling the modified Samlex inverter with each of my previous campers. I modified them so fan is connected to a thermocouple switch which means my fans never come on unless I'm running the microwave or a hair dryer.

With less than 1 amp draw on standby, I've decided against using a smaller inverter for low power uses in my camper. If you have an older inverter that draws a lot of power on standby, then a smaller PSW inverter is a good option.