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run 13,500 air conditioner from batteries?

Is it reasonable to think I can run a 13,500 btu air conditioner from a 12/3000/120 and 6 battleborn lithium in parallel @ 12v? (and of course nothing else at the same time)

After a couple of years acquiring stuff, I have just finished setting up my whole infrastructure in my RV (yah me!). As mentioned I have (6) 12v lithium in parallel, 5' of 4/0 between the battery output and the inverter. I tested the air conditioner and the fan started, but as soon as the compressor started it shut down. I looked at the alarms and saw I had previously set with the VE.Config, the DC low shutoff at 11.5 per a blog on the battleborn website. I lowered that to 11.0 and was able to get the compressor to come on for about 30 seconds before it hit the 11v threshold.

My batteries are fully charged and show 14.6v on the cerbo gx screen (pictured below) before I start the air conditioner. When the condenser turns on the AC loads show 1100'ish to 1300'ish watts, the battery bank shows -1300'ishW and dips to 13.1v and up to -123 amps. Within a short time something else happens that then draws more and it shows -126 amps and the inverter shuts down.

I read on the battleborn specs that their batteries...

"allows for 100 Amps continuous, 200 Amp surge for 30 seconds, and 1/2 second surge for loads over 200 Amp"

Before the air conditioner is turned on:


This is about the highest surge I've seen during compressor startup:


This is when it shuts down:


According to the numbers from the bottom left blue battery icon (the shunt) I have not surpassed these values, but could there be a huge drop on the 5 feet of 4/0 to the inverter?

If so what is the solution? I'm not sure I can fit another 400amp fuse and 500amp shutoff switch to duplex my cables in my battery bank box. I thought 4/0 would handle this very well over 5 feet.


solar->breaker->charge controller->breaker->batteries
the battery out, pos and neg are on opposite ends of the bank to draw from the whole bank
neg->500amp shunt->lynx->inverter
pos->400amp fuse->500amp cutoff switch->lynx->inverter

Thank you

me1 asked
trevor-bird commented ·

9 Answers

Phoenix MultiPlus charging batteries when Air Conditioning Runs

I have an older Phoenix Multiplus Inverter charger 12/3000/120v. I am connected to shower power. When the air conditioning cycles on the batteries are getting charged (bulk, abs ect) which is seemingly over charging them. I thought when shore power was connected the inverter/charger is bypassed. It seems like the inverter is running off of the batteries and charging them when there is an AC load. Or is this part of a battery assist when the air conditioning starts? Any help here would appreciated!

thank you.


rockland asked
Kevin Windrem commented ·

2 Answers

Multipluss II 2x120 not passing through enough power to run the air conditioning from the generator.

New install of a Multiplus II. Generator runs fine and the Multiplus charges the battery bank perfectly. When the air conditioning unit is turned on the multiplus will still run 80 amps from the charger (what it is set at) and the air conditioner for a few minutes. Then the generator shuts off. 5500 onan. It seems the multiplus is not diverting the charge power to run the air conditioning unit and the generator quits. One year old fifth wheel. Generator has never been an issue and was serviced 5 months ago. Am I missing a setting to force power to the load vs the charger?

Thank you.


bishop asked
bishop commented ·

1 Answer

a ~0.4 seconds electricity "blink" every time a 3-phase air-conditioner motor starts

I have a 3-phase off-grid Victron system (no other source of energy, only batteries), 10kva inverter each, the battery bank is 1000AH, connected by a 95mm² cable (2 meters length) to the bus bar.

the bus bar is connected to the inverters with a 70mm² cable (1.5 meters length) each.

as for the AC output, a 10mm² cable (3 meters length).

now for the issue:

the house has various led lights and electric machines such as treadmills, water cooler...etc.

there are 4 air conditioners in the house, one of them is large (see spec image below), and it's a problem! once it's large motor starts (on remote command or after a waking up from power conservation mode) there's a blink on electricity that affects all the led lights (they go off and on again in a span of ~0.4 seconds), the treadmill stops instantly (which is very dangerous!), while other devices aren't affected at all, i.e: computer screens and TVs.

this is very annoying to the owner of the house and extremely dangerous in case of treadmills usage.

I tried the change the "boost power assist" configuration (default was 2, tried 1.5 and 2.5) but it didn't help.

I'm out of ideas and I have to solve this issue asap, your input is highly appreciated.

thank you.


muhamad asked
trevor-bird answered ·

3 Answers

Phoenix Inverter 24/2000 230V to power an Split phase Air conditioning?

Anyone have tried to power up an American Split phase air conditioning with a 230V Phoenix inverter with the 60hz option?. is it possible.?

sebastianlehmann asked
Matthias Lange - DE commented ·

2 Answers

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