5 ms·

Seems strange to call it a "zero-battery-use fridge" and then follow it with "It ties into the typical offfgrid system of a solar charge controller, battery ba

Seems strange to call it a "zero-battery-use fridge" and then follow it with "It ties into the typical offfgrid system of a solar charge controller, battery bank, and photovoltaic panels"

dang 8y ago
We changed the title from "Fridge 0.2 offgrid, solar powered, zero-battery-use fridge has made it through".
Scoundreller 8y ago
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.
- realityczeque 8y ago
  Or you can just buy a DC refrigerator.
  - Scoundreller 8y ago
    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.
- nerpderp82 8y ago
  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.
  - abraae 8y ago
    Or an ordinary (and cheap) lead acid car battery. These are designed for very high, short term loads, perfect for this application.
    - kragen 8y ago
      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.
- cuban-frisbee 8y ago
  If you need high current draw followed by low draw, you could use a flywheel.
  - Scoundreller 8y ago
    I was thinking of a kickstart :)

Seems strange to call it a "zero-battery-use fridge" and then follow it with "It ties into the typical offfgrid system of a solar charge controller, battery bank, and photovoltaic panels"

dang 8y ago

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

Scoundreller 8y ago

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.

realityczeque 8y ago
Or you can just buy a DC refrigerator.
- Scoundreller 8y ago
  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.
nerpderp82 8y ago
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.
- abraae 8y ago
  Or an ordinary (and cheap) lead acid car battery. These are designed for very high, short term loads, perfect for this application.
  - kragen 8y ago
    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.
cuban-frisbee 8y ago
If you need high current draw followed by low draw, you could use a flywheel.
- Scoundreller 8y ago
  I was thinking of a kickstart :)