Question about inverter for small air conditioner

[mos6510]

I'm considering running a small 5,000BTU window air conditioner off a 12V inverter connected to a set of batteries. Finding details about LRA without first buying a unit and checking the compressor is an issue. Can someone recommend a 12V inverter that can handle the start up surge and run while connected to a LiFePO4 battery with a 120A Overkill BMS? I'm seeing conflicting information, so any help would be appreciated.

 

[RV10flyer]

How many aH on your 12V battery? How many watts of pv? One is likely not going to cut it. I have about 630 aH 24V LFE battery (split in two for redundancy), two JK BMS, 1000W pv and a Magnum 4000W 120V inverter running a 9000 btu, 22 SEER mini split hp in my van.

 

[mos6510]

No PV or batteries yet. I was planning to run 4S 280aH battery first, to get familiar before proceeding. A 5000 BTU should be running around 450 watts after startup. The real question is whether an inverter connected to a 120A Overkill BMS can handle the startup current. I know inverters rely on internal capacitors to some degree, and they are an expensive thing to get wrong.

Thanks!

 

[time2roll]

I run a 1/2 hp 820 watt water pump with a single 120A Overkill BMS and 1000 watt inverter.

 

[mos6510]

I run a 1/2 hp 820 watt water pump with a single 120A Overkill BMS and 1000 watt inverter.

Do you know what surge current it has for startup and which inverter is that?
Thanks.

 

[time2roll]

I have a GoPower sine wave inverter. IIRC the BMS recorded close to 1400 watts surge and about 100 amps. The actual shut down is 130 amps on the BMS after several seconds to get through a surge. Short circuit will shut down immediate.

 

[rmaddy]

A 120A BMS at 12V means you can support about 1400W so your inverter can't be any bigger than that. Though the BMS might handle a bigger surge for a few seconds to handle the A/C starting up. A 450W A/C is unlikely, I think, to surge more than three times on startup. So you should be OK with a 1200-1400W inverter.

I have a 5000 BTU window A/C being run on a 24V, 2000W inverter without any issues. My A/C hits about 430W when running full blast but I have no idea what the startup surge might be.

 

[Al D]

The general rule of thumb, I've heard, is to multiply the operating current by a factor of 6 to achieve the inrush current.