Frustrated with battery install

[docj]

2- specific issue has nothing to do with a/c EXCEPT that if load on system is too high it should have breaker or something to stop it. I’m NOT expecting system to run a/c. I’m frustrated that when a/c was turned on, inverter started steaming instead of flipping a breaker.

That's not how inverters are usually wired into an RV. In my MH my inverter has a 30A breaker in front of it and two subpanel breakers after it. Devices that I want the inverter to be able to power are fed through the subpanel. Other devices, such as the microwave, the air conditioners and the water heater all have their own breakers and aren't fed by the inverter. Your problem came about because the A/C was powered through the inverter which is not the standard practice.

 

[Kevin D Pem]

specific issue has nothing to do with a/c EXCEPT that if load on system is too high it should have breaker or something to stop it. I’m NOT expecting system to run a/c. I’m frustrated that when a/c was turned on, inverter started steaming instead of flipping a breaker

This means you were plugged in? If so your inverter may have had 115ac back fed to the finals of the inverter. If so the inverter may well be toast. A transfer switch should be a part of the circuit.

 

[kangarooelaine]

I'm kind of confused. Did you have an additional inverter and additional batteries installed in addition to the ones you had before? So now you have 2 inverters and 2 battery banks?

No. My motorhome is a 2019 Minnie Winnie 22R. It came with 100 amp hour lead acid battery bank and no inverter.

We replaced those batteries with four 100 amp-hour Go Power Lithium Iron Phosphate Solar Batteries and added a 2000-watt Go Power IC Series inverter charger.

The motorhome has an on-board 4000-watt Onan generator. Originally the house batteries recharged en-route. The tech 'turned that off because it confused the inverter."

The voltage on your display will change depending on which phase of charging (Bulk, Absorb, Float) the inverter is in during the charging cycle. Even after charging they need to settle down for several hours before you can get an accurate reading. As I mentioned, it’s best to test the voltage with a multimeter at the battery terminals. If they test ok, then you know the inverter is properly charging the batteries.
Then you can begin a rundown test, watching the voltage with a load turned on to see how fast the voltage drops. With a 400 hour battery bank you should get approximately 10 hours out of a 20 amp load until the batteries are down to 12 volts which is typically the lowest you want to go before recharging.

As others have mentioned, it may not be with the batteries or charging system, but it’s good to rule it out before proceeding.

We will test soon. This is not a priority for hubby so I may need to cancel another one of my trips before it all gets done. So far it's 3 canceled trips because of this failed project and one trip we refused to cancel but was sub-optimal as a result.

That's not how inverters are usually wired into an RV. In my MH my inverter has a 30A breaker in front of it and two subpanel breakers after it. Devices that I want the inverter to be able to power are fed through the subpanel. Other devices, such as the microwave, the air conditioners and the water heater all have their own breakers and aren't fed by the inverter. Your problem came about because the A/C was powered through the inverter which is not the standard practice.

This inverter appears to be designed to be sort of 'plug and play'. I don't think it's the same as how yours is set up.

This means you were plugged in? If so your inverter may have had 115ac back fed to the finals of the inverter. If so the inverter may well be toast. A transfer switch should be a part of the circuit.

Plugged in when? Not during that first shake down trip when the inverter started steaming.
After, yes. But batteries never seemed to hold a charge.

 

[Sonic]

No. My motorhome is a 2019 Minnie Winnie 22R. It came with 100 amp hour lead acid battery bank and no inverter.

We replaced those batteries with four 100 amp-hour Go Power Lithium Iron Phosphate Solar Batteries and added a 2000-watt Go Power IC Series inverter charger.

The motorhome has an on-board 4000-watt Onan generator. Originally the house batteries recharged en-route. The tech 'turned that off because it confused the inverter."



We will test soon. This is not a priority for hubby so I may need to cancel another one of my trips before it all gets done. So far it's 3 canceled trips because of this failed project and one trip we refused to cancel but was sub-optimal as a result.



This inverter appears to be designed to be sort of 'plug and play'. I don't think it's the same as how yours is set up.



Plugged in when? Not during that first shake down trip when the inverter started steaming.
After, yes. But batteries never seemed to hold a charge.

As I stated, my advice assumed lead acid batteries, much of which does not apply to lithium batteries, so nevermind.

 

[Kevin D Pem]

Plugged in when? Not during that first shake down trip when the inverter started steaming.
After, yes. But batteries never seemed to hold a charge

make sure your charge voltage is correct. the BMS will only charge the cells properly if the charge voltage is high enough.

If the inverter is not designed for this charge voltage it will fail as well.

 

[kangarooelaine]

UPDATE:
The 2nd shop we took it to discovered that the original installation was done with the wrong gauge wire!
There was evidence it caught a small fire and luckily the damage wasn't so severe that it can't be fixed. But currently it's a fire hazard.
I missed out on my Summer travels because that idiot used the wrong type of wire for my install! And now I have to wait for all these repairs before I can use it again.

LESSON:
Make sure you use an installer who knows exactly what they are doing if you add solar or extra batteries.

 

[Joe Hogan]

Just an FYI for next time

wire gauge chart at DuckDuckGo

DuckDuckGo. Privacy, Simplified.

duckduckgo.com

 

[Bob K4TAX]

From my limited knowledge 1 amp = 92 watts. Average A/C is 13 amps, = 1200 watts. Not including the startup surge load.

NOPE! Volts X Amps = Watts. Thus 13 amps X 120 volts = 1560 watts. That's running, not starting which could easily be 2X that amount.

From a 12 volts system, that is basically 120 amps not including inverter efficiency which is about 80% or 1862 watts. So the DC load on the batteries would be near 150 amps. That is a LOT to pull from batteries and the cable from the batteries to the inverter needs to be about the size of your thumb.

I = P watts/E volts Thus I = 1862/13 or 144 amps

I think folks need to look at the numbers and then decide.

 

[Bob K4TAX]

I always say there are 2 types of folks:
(a) those that THINK they know what they are doing.
(b) those that KNOW what they are doing.
Try to be in group (b) or use those in group (b).
'cause there LOTS of folks in group (a).

 

[Rich W.]

Still haven’t heard the brand/model inverter or batteries. My guess is that this substandard equipment and/or poorly designed/wired/installed. Also if you’ve already let the smoke out, the inverter is probably junk. Which would explain the charging issues.

I have a Magnum 2kw inverter and a bank of 6 LA house batteries and it easily hamdles the loads of a residential fridge, coffee maker, toaster, microwave, etc, although not all at once of course. I wouldnt consider trying to start an AC with it.

I built a system on a previous rig with a 3kw Victron inverter and a big bank of Li-ion (Nissan Leaf) batteries that handled an AC for about 7 hours after sundown on a full charge, but this was an elaborate system, around $5-6k (including 1975w solar), designed and installed by my son and me. You can’t buy an installed system like this for under $20k. Probably more like $25k.

Most installers of aftermarket RV power systems and over-priced and under-qualified. It’s one of those unregulated markets ripe for huge profits for sub-standard products and services.

So:
1. Battery brand/model and battery bank size?
2. Inverter brand/model?
3. Can you post some pics of the install?

PS - do not let these guys sell you solar! Yes the extra power would help maintain the battery bank while the sun is shining, but thats not the problem. More on that later if you are interested.