Inverter/microwave Excessive Load - Troubleshooting Help Needed

[TucsonJim]

In 2018, I installed three 100 AH Battle Born batteries. I also installed a 2000 Watt pure sine inverter from Kisae that I purchased on Amazon. I connected the inverter to the battery bank with 2/0 AWG wire.

For the first few years, I could power my microwave for 5-10 minutes with no problem. Now, when I try to use the microwave, the inverter shuts down after about 20 seconds and then powers back on. If I hit the microwave start button again, the process repeats.

I thought maybe my 12V DC refrigerator may be drawing enough current to overload the inverter. So I shut off the refrigerator and every other 12V load I could think of. I attached an amp meter to the battery lines and there was no current flow. Next, I repeated trying to use the microwave and got the same 20 second shut down routine.

My next trouble-shooting will be to check for loose or contaminated connections from the battery to the inverter.

I'm wondering if my 5-6 year old Battle Born batteries may not be able to provide the current needed?

Any other suggestions on what to check?

Thanks,

Jim

[ncitro]

TucsonJim While its possible, I would be surprised if the problem was in the batteries. Given the troubleshooting we went through with WondersAwait levelers I would suspect a loose or corroded connection. We progressively worked back from the batteries until we found a decent voltage drop (about .75V at rest) across a connection. When we opened it up we found the connection a little loose and the strands were discolored, stiff and obviously had been overheated.

Does your clamp have a trigger record feature to show you the highest current recorded? I would be curious if its spiking before shutdown or if the inverter is tripping at a "normal" amount of current.

[howson]

Any other suggestions on what to check?

Could it be the microwave? If you have a Kill-A-Watt it's easy to see the power (and amperage) draw.

Heck, it could be the outlet if it's still the standard RV type.

According to the Kisae specs, the max sustained current is 16.6A. That's very close to what a microwave draws. https://www.kisaepower.com/wp-conten..._DATASHEET.pdf

Is there an error code on the Kisae? If it's sensing an overload it should throw an E03.

I also doubt it's a battery issue -- if there was an under-voltage condition the Kisea should show an E01. Easy enough to monitor the battery voltage, too, with your meter.

Just tossing out ideas. No doubt you'll figure this out.

Howard

[Yoda]

In 2018, I installed three 100 AH Battle Born batteries. I also installed a 2000 Watt pure sine inverter from Kisae that I purchased on Amazon. I connected the inverter to the battery bank with 2/0 AWG wire.

For the first few years, I could power my microwave for 5-10 minutes with no problem. Now, when I try to use the microwave, the inverter shuts down after about 20 seconds and then powers back on. If I hit the microwave start button again, the process repeats.

I thought maybe my 12V DC refrigerator may be drawing enough current to overload the inverter. So I shut off the refrigerator and every other 12V load I could think of. I attached an amp meter to the battery lines and there was no current flow. Next, I repeated trying to use the microwave and got the same 20 second shut down routine.

My next trouble-shooting will be to check for loose or contaminated connections from the battery to the inverter.

I'm wondering if my 5-6 year old Battle Born batteries may not be able to provide the current needed?

Any other suggestions on what to check?

Thanks,

Jim

Jim I am far from and expert here, but I think Howard has the place to start. What load is the microwave drawing? As it is so close to the inverter specification it could be just an age thing either the microwave or the inverter.. Also is the inverter venting clear of dust and stuff - could it be overheating?

Of course the ultimate solution is to rip out what you have and put in a Victron Multiplus of the correct size. just saying . I need to do my part in fulfilling the forum goal. just not my money this time.

Keith

[TucsonJim]

Jim I am far from and expert here, but I think Howard has the place to start. What load is the microwave drawing? As it is so close to the inverter specification it could be just an age thing either the microwave or the inverter.. Also is the inverter venting clear of dust and stuff - could it be overheating?

Of course the ultimate solution is to rip out what you have and put in a Victron Multiplus of the correct size. just saying . I need to do my part in fulfilling the forum goal. just not my money this time.

Keith

LOL. Ginnie's first words were "Why don't you just put a bigger inverter in?". Of course, it's not just the inverter. I'd have to rewire from 2/0 to 4/0 if I put in a 3kW inverter.

Jim

[Country Campers]

Jim,

Does the inverter have receptacles? If so run an extension cord from microwave to inverter, eliminates everything in between.

Brian

[Yoda]

LOL. Ginnie's first words were "Why don't you just put a bigger inverter in?". Of course, it's not just the inverter. I'd have to rewire from 2/0 to 4/0 if I put in a 3kW inverter.

Jim

How much 4/0 do you need. I have some spare I could bring to the rally But I really think Blue is in your future, Besides you can power the whole trailer and not need to rewire that much.

Keith

[ncitro]

LOL. Ginnie's first words were "Why don't you just put a bigger inverter in?". Of course, it's not just the inverter. I'd have to rewire from 2/0 to 4/0 if I put in a 3kW inverter.

Jim

Well I mean that would certainly take care of any loose or overheated connections on the DC side lol.

[Scott'n'Wendy]

Put an ammeter on the microwave wire. If voltage is dropping you will see an increase in amperage that would trip the inverter. If amperage is normal for the mwave, then you have an inverter issue. It may be as simple as the breaker being faulty.
If the amperage for the mwave is high, then you will need to track the voltage op of the battery and determine if it is the battery or poor downstream connections.

[TucsonJim]

Put an ammeter on the microwave wire. If voltage is dropping you will see an increase in amperage that would trip the inverter. If amperage is normal for the mwave, then you have an inverter issue. It may be as simple as the breaker being faulty.
If the amperage for the mwave is high, then you will need to track the voltage op of the battery and determine if it is the battery or poor downstream connections.

How would you put an ammeter on an AC wire?

Jim

[Scott'n'Wendy]

You need to make a "special" cord. Using individual wires with regular plug ends. It's handy to have because you can use it for all your 120vac appliances

[StephenO]

How would you put an ammeter on an AC wire?

Jim

If you're not up to making the cable that Scott'n'Wendy mentioned, they also make A/C line splitters.

https://www.homedepot.ca/product/kle...10x/1001012659

Of course, this means you need a clamping multimeter, and if you don't have one already......well, now you have an excuse

[Country Campers]

LOL. Ginnie's first words were "Why don't you just put a bigger inverter in?". Of course, it's not just the inverter. I'd have to rewire from 2/0 to 4/0 if I put in a 3kW inverter.

Jim

No need for the 4/0 just add another pair of 2/0. The Victron states double 2/0.

Brian

[TucsonJim]

Scott'n'Wendy StephenO

Great, another gadget to buy and pack...

Jim

[Yoda]

Scott'n'Wendy StephenO

Great, another gadget to buy and pack...

Jim

Is it not wonderful to have friends like us? ....yep back to my corner