Nature power inverter won’t run micro

[JPetronek]

Hello, new here. I am not new to solar and rv systems but far from an expert.
I have a toyhauler that came with a 160 watt panel, 30 amp pwm, I installed a 2000/4000 nature power pure sine wave inverter with 3 100 ah 12v flooded batteries.
I know my panel is way under sized, we don’t run huge loads off inverter especially for long times. My main problem and I think I already know why but want to hear from some smarter people- I can’t run my microwave. It’s a 900 watt? Factory unit I believe, it kicks on and after about 5-8 seconds puts inverter into a error. I don’t know why can’t tell code. I’m assuming it’s due to type and size of batteries? I have 2/0 wire going to the inverter and they are only about 3’ long each.

 

[Supervstech]

Most inverters can’t handle the demand of a microwave... the 4000surge is only for a fraction of a second... that 900 watt rating is just the heating coil... the entire mw needs around 2700watts for several seconds at a time over and over during cook time.

The wire size is good, but the inverter just cannot output the surge watts long enough.

You will need a LF big iron inverter, or a 3000watt decent hf model.

 

[JPetronek]

Thanks for the info. That explains a lot. I always knew microwaves were a little different than any other appliance but didn’t know those numbers.

 

[Ped]

Try turning power level to 50-70%

 

[stuart]

I'll take another approach, check the size of the cables interconnecting your batteries. Sure they may be able to push a lot of current but from where the inverter is connected it could be drawing power from mostly one battery, because the interconnecting wires to all batteries is not sized properly. This would cause a momentary low voltage to the inverter during the heavy load that would disappear immediately when the inverter stalls out.

 

[JPetronek]

I have the same cabling from battery to battery as I do to the inverter. I also ran the inverter pos on one battery and Meg on another to try and help balance the draw if that even matters?

 

[Supervstech]

I have the same cabling from battery to battery as I do to the inverter. I also ran the inverter pos on one battery and Meg on another to try and help balance the draw if that even matters?

Ok, but what size and material are the wires?

 

[JPetronek]

Ok, but what size and material are the wires?

2/0 wire. Size of my thumb.

 

[JPetronek]

Copper wire, copper terminal

 

[Supervstech]

I have the same cabling from battery to battery as I do to the inverter. I also ran the inverter pos on one battery and Meg on another to try and help balance the draw if that even matters?

Copper wire, copper terminal

Ok. All 2/0 copper, with copper terminals. Tied into lead batteries. My next guess is the lead terminals may have corrosion or oxidation... what material does the sla cells have? Are they clean and sealed to your lugs?

 

[JPetronek]

Ok. All 2/0 copper, with copper terminals. Tied into lead batteries. My next guess is the lead terminals may have corrosion or oxidation... what material does the sla cells have? Are they clean and sealed to your lugs?

Sadly they aren’t SLA, old style lead acid. Batteries are the next thing on my list after I get solar in and wife off my back. Batteries are brand new though and contacts are clean. They are cheap batteries for now as my originals that came with the trailer failed early from what I suspect as being ran dead to many times from tt being a show model but I couldn’t prove that to make them warranty.
I threw cheap in for now until I get solar built and then upgrade my batteries.

 

[Ped]

Its just pulling voltage down real low and triggering the LV alarm or disconnect on the inverter. Batteries cant handle it. Agm's or Lifepo4 would.

 

[Supervstech]

Sadly they aren’t SLA, old style lead acid. Batteries are the next thing on my list after I get solar in and wife off my back. Batteries are brand new though and contacts are clean. They are cheap batteries for now as my originals that came with the trailer failed early from what I suspect as being ran dead to many times from tt being a show model but I couldn’t prove that to make them warranty.
I threw cheap in for now until I get solar built and then upgrade my batteries.

Ahh... cheap FLA cells... how many? What voltage! Ah ratings? We may have found the weak link...

I guess if I read the first post, this info would all be spelled out for me...

100Ah FLA should handle the load, depends on the chemistry and build design... they may not be able to handle the amperage load...

 

[Ped]

They can only handle about c/6 - 50A

900w - ~70-80A at terminal with inverter loss