Any chance a 400W continuous (800W peak) inverter will run any small chest freezer?

ecwashere

New Member
I'd like to be able to power a small 3.5 cuft chest freezer or similar from a Cobra CPI 475 12V 400W inverter connected to a yet-to-be-built ~13V battery bank. The freezer will be connected to AC most of the time and only connected to the inverter during a prolonged power outage.

Small chest freezers draw ~150W while running intermittently. The obvious hurdle is getting past the startup surge and working with a modified sine wave inverter. This inverter claims it has an 800W peak. I'm planning on using beefy and short cabling between the battery and inverter.

Has anyone been able to get any small chest freezer to work with an inverter with similar specs? I just want some battery powered freezing available so all my meat doesn't go bad and so I can still have some cold beer to share with the zombies.

I did see a thread here where someone failed to do something similar with a mini-fridge and a 300W inverter with unspecified max. I believe chest freezers are more efficient than mini fridges (mostly because the air doesn't fall out when you open from the top), but I'm not sure if they require more or less startup current.

DC chest freezers are probably quieter and more efficient but I don't think the price justifies them for my just-in-case scenario.

If it doesn't work, I'll invest in a higher capacity pure sine inverter and maybe just build a 24V or 48V system. But since is this really the only critical load I need to run, I'm trying to make it work with what I have.
 

snoobler

Solar Honey Badger
Moderator
MSW don't do well with motors. Net effect is a HIGHER current draw. Peak claims on cheap inverters are usually for fractions of a second where they aren't meaningful for the longer duration surge.

I have this little cheapo, and it easily runs a small air compressor.


Compressor:


I powered it through a 120W cigarette lighter port once, and it popped the fuse, so it's higher than 120W :)
 

Pnw_steve

Solar Enthusiast
Probably not.

It may well support "running" current. but will choke on the "sartup" current draw. Also, your freezers compressor may run hot, reducing lifespan, if you use a MSW inverter. I killed a Frigidaire running it for an extended period on an MSW.

I went through a number of inverter looking for a good match for a 10.8 cf refrigerator/freezer. I found some cheaper 1400-1500 watt inverters that wouldn't work. I finally settled on a Xantrex 1000 watt PSW. It has been flawless for 6+ years.
 

ecwashere

New Member
I appreciate the great advice.

I'll get the chest freezer soon because my freezer is getting full. I can test it with a 12V car battery and this inverter to see if it'll even start up. However, based on what you're saying, even if it does run, I shouldn't run it for long periods without a PSW.

I should probably build a 24V or 48V battery system. They inverters were so much pricier when I last checked.

...And yeah, per the manual, the inverter can handle 800W for 0.1 sec.
 

Pnw_steve

Solar Enthusiast
My new rig is getting a Xantrex Prosine 1800/24. I have a couple of them. I don't recall them being very much more expensive than the 1800/12.

The 400 watt msw DEFINITELY does have the capacity to overcome LRC.
 

Pnw_steve

Solar Enthusiast
:) I'll sell you the Xantrex 1000 that I have...... It does come with a travel trailer and pickup truck attached to it though...... :)
 

snoobler

Solar Honey Badger
Moderator
Normally, I would agree, but LF inverters tend to be less efficient and may have higher idle consumption. Given the anticipated surge, I'd just use a cheap HF PSW inverter with rated continuous output above the surge. 800-1000W in this case.
 

Bud Martin

Solar Addict
Bur for emergency during power outage is OK in this case I would think. HFPSW has surge duration of abou 50 milliseconds which is not much.
 

Delmar

Solar Addict
I would run a small UPS. Low-frequency for good starting surge, pure sine, and works autonomously if you lose power when away from home.

I bought this used UPS for $240 on eBay including two new 18AH AGM batteries. Can't get much more simple. Show and Tell. Make sure you get the XL model rated for continuous duty.
 
Top