Mostly agreed.

The big issue with off-the-shelf AC fridges is the current draw required for them to start.

If you want to go completely zero-battery, you’ll need to highly-oversized your PV array just to handle the 1-2 second inrush starting current.

Or devise a slow-start function, overriding the AC flow to the compressor. So instead of starting at 60hz, you would start at 1, then 2, then 3hz, etc.

I guess OP means they could add a fridge to their off-grid setup without changing their existing battery budget for their other needs.

One could have a high current lipo connected to the inverter that can supply > 2kw for seconds. A 14.8v 4Ah 50C battery can supply 3kw for 72 seconds, more than enough to even out start/stop and shade cycles.

Or an ordinary (and cheap) lead acid car battery. These are designed for very high, short term loads, perfect for this application.

Some LiPo batteries, like those used in quadcopters, actually have power densities more than an order of magnitude better than lead-acid batteries; I think they can be small enough that they're even cheaper.

If you need high current draw followed by low draw, you could use a flywheel.

I was thinking of a kickstart :)

Or you can just buy a DC refrigerator.

They’ll cost you a lot of extra $$$. Consumer stuff is cheap, but once it’s built slightly differently for the specialized off-grid market, the price skyrockets.

We changed the title from "Fridge 0.2 offgrid, solar powered, zero-battery-use fridge has made it through".