Power inverters

Susquatch

Ultra Member
Administrator
Moderator
Premium Member
No I’ve never measured it, but this truck doesn’t seem to charge as high as my last one. I see a lot more 13-13.5 volts with this truck versus the last truck was

My guess is that this observation is most likely just voltage gauge accuracy. All those old gauges were really crappy by modern standards. Some vehicles are still like that. As far as I know, fuel tank sending units have never changed. These old heated element gauges were almost as good as ruler marks on a soft elastic band.
 

YotaBota

Mike
Premium Member
CL - is your inverter mounted direct to the bulkhead or are you using isolation mounts? The rubber mounts will help a lot in the extending the life of the inverter. Having separate house batteries will also help keep the power fluctuations to a minimum again extending the life of the inverter.
I don't think it's a fair to compare CL's rig to an RV. Most RV's are driven or towed a few hundred (maybe thousand ) kms a year and parked most of the time where as the rig can be driven everyday for hundreds of thousands of kms a year in all kinds of weather. The RV just won't see the use and/or abuse that the rig does.
 

Chicken lights

Forum Pony Express Driver
CL - is your inverter mounted direct to the bulkhead or are you using isolation mounts? The rubber mounts will help a lot in the extending the life of the inverter. Having separate house batteries will also help keep the power fluctuations to a minimum again extending the life of the inverter.
I don't think it's a fair to compare CL's rig to an RV. Most RV's are driven or towed a few hundred (maybe thousand ) kms a year and parked most of the time where as the rig can be driven everyday for hundreds of thousands of kms a year in all kinds of weather. The RV just won't see the use and/or abuse that the rig does.
It’s more of a cabinet, that’s bolted to the floor overtop 1” of insulation. First cobra and first Samlex were bolted to the side of it, second Samlex was sitting loose on top of a toolbox that isn’t bolted down. I can add in some rubber feet for the next transition

I’m starting to learn just how much stuff can break just from hammering on poor roads. I guess I shouldn’t say I get a year out of a power inverter, instead she was good for 150,000 kilometres
 

Susquatch

Ultra Member
Administrator
Moderator
Premium Member
It’s more of a cabinet, that’s bolted to the floor overtop 1” of insulation. First cobra and first Samlex were bolted to the side of it, second Samlex was sitting loose on top of a toolbox that isn’t bolted down. I can add in some rubber feet for the next transition

I’m starting to learn just how much stuff can break just from hammering on poor roads. I guess I shouldn’t say I get a year out of a power inverter, instead she was good for 150,000 kilometres

You are spot on @Chicken lights ! That's an excellent way to look at it!

Let me illustrate. One of the durability laboratories we had during my career was equipped with a variety of Road Test Simulator's (RTS for short). These were giant high velocity Hydraulic fixtures that an entire car or truck was mounted to and then tortured till they broke.

The Idea was to instrument a vehicle with strain gauges, accelerometers, and other instruments and drive it on the worst roads we had at our proving grounds or in the real world, collect all the data, and then use this data to tune the RTS such that the vehicle's instrumentation showed the same responses that it did on the road.

The data was then analysed to remove all the non-damaging inputs so the vehicle only saw the very worst inputs it had ever seen.

As a result, the subsequent testing could subject a vehicle to the equivalent of a lifetime of real world driving on the worst roads in just 2 or 3 weeks, and no driver got their bones smashed up in the process.

You are right, time isn't really important. It's the life cycle that counts. Total kilometers is a much better proxy than years. But the kinds of cycles (road quality, precipitation, humidity, and temperature) that it sees during those km's is extremely important too.

Rubber mounts are a great idea, but their damping response is important too. I find that foam is very effective - perhaps more so than rubber isolators for things like inverters and such.

Or, you could make an RTS for your inverter and use it to minimize the inputs the inverter sees...... Just kidding, but you get the idea.
 
Last edited:

Chicken lights

Forum Pony Express Driver
1E0AFEFE-A137-479B-87A2-EDBF6CC48298.jpeg 398DCECB-BDA9-4B6F-8003-E00ED5804D90.jpeg E04E4C19-67E0-457C-9FCF-855DDA86D5AF.jpeg Picked up a cheap-ish Dewalt once we was back across the border. Goofy ends on the cables we farmer fixed that

But now the new one won’t turn on :(

I’m giving up for tonight
 

Chicken lights

Forum Pony Express Driver
I got the screen on the new inverter to flicker blue but that’s it, so more junk from China is my guess.

I don’t have time for this I have work to do
 

Susquatch

Ultra Member
Administrator
Moderator
Premium Member
I got the screen on the new inverter to flicker blue but that’s it, so more junk from China is my guess.

I don’t have time for this I have work to do

Ya, best done when you have the time and the patience.

Then again, sometimes I have to buy some junk just so I can develop the courage to buy a good one.
 

Chicken lights

Forum Pony Express Driver
308DCA56-C5B1-4331-B272-DAEE6B145077.jpeg Still no bueno. I’m not understanding this

Sept- Truck running, high idle, wouldn’t run the microwave

Sept- Truck running, low idle, printer plugged in (not printing), laptop wouldn’t power up

Oct 4- First phone call to tech support, 45 minutes on hold, got cut short because I had a meeting, their initial thought was the printer was a power hog (?)

Oct 28- 4 new batteries, alternator was new around May 2022, found 3 bad battery cables, fixed 2, had to leave the 3rd

Still will not run the microwave. Says it’s 1100 watt input, 700 watt output (truck running)

Owners manual says I should be running 2 gauge wire, I have 4 gauge, it’s approximately 6 feet from the batteries to the inverter

Positive for the inverter is on one battery, ground is on an opposite battery

Within 10 seconds of running the microwave, the voltmeter on the dash drops dramatically (truck running), and the error message E06 flashes, connected load is too high

Other than another call to tech support, which I’ll do next week, I’m stumped
 

Susquatch

Ultra Member
Administrator
Moderator
Premium Member
View attachment 27490Still no bueno. I’m not understanding this

Sept- Truck running, high idle, wouldn’t run the microwave

Sept- Truck running, low idle, printer plugged in (not printing), laptop wouldn’t power up

Oct 4- First phone call to tech support, 45 minutes on hold, got cut short because I had a meeting, their initial thought was the printer was a power hog (?)

Oct 28- 4 new batteries, alternator was new around May 2022, found 3 bad battery cables, fixed 2, had to leave the 3rd

Still will not run the microwave. Says it’s 1100 watt input, 700 watt output (truck running)

Owners manual says I should be running 2 gauge wire, I have 4 gauge, it’s approximately 6 feet from the batteries to the inverter

Positive for the inverter is on one battery, ground is on an opposite battery

Within 10 seconds of running the microwave, the voltmeter on the dash drops dramatically (truck running), and the error message E06 flashes, connected load is too high

Other than another call to tech support, which I’ll do next week, I’m stumped

Sounds odd to connect to two batteries unless they are in parallel. Most inverters are 12V not 24V. Not sure what you have there.

The cable size called for is bigger than you are using, but either way, a 2 or 4 cable suggests 12V not 24. Typically lower voltages require bigger cable. I know that isn't intuitive. Just trust me on that one.

What does it call for and what are you feeding it?

Regardless, back to the cable for a second. Big cables need GREAT connections. A poor or small connection will cut the cables capacity out from under it. Cable Clamps don't generally cut it. Needs to be a regular battery clamp bolted onto the battery terminal. Not always easy to do for secondary loads. But you can get battery clamps that will connect two high current loads at once. That's probably what you need here.

The draw too high suggests a short circuit or a load not designed for an inverter - eg a 120V device on a 240v circuit.

Also possible the load doesn't like a square wave power source or something like that.

Do you have a decent multimeter? If you have a good one, you can measure the voltage drop across one of the cables to calculate actual input and output current and voltage. Don't try to use the meter in current mode unless you have a current loop for it - you will fry it.

At any rate, my very first check after looking at wires and connections would be to do voltage and current checks on everything.
 
Last edited:
Top