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macrumors newbie
Original poster
Sep 23, 2021

I was wondering if anyone can help me wrap my head about calculating how much I have to work with when it comes to using a battery when camping.

If I use a Rita’s AGM Battery 12v - 120Ah Battery how long would it last while running a 43.5L over 24 hours and charging a 2014 MacBook Air. How long would the battery last before needing to be re-charge via solar?

The setup:


  • 2014 13” MacBook Air (7160 mAh battery / 54‑watt‑hour lithium‑polymer battery / 45W Power Adapter for charging the laptop)
  • 43.5L Fridge Freezer at 0.88 Ah/h @12V (0.88 Ah x 24h = 21.12ah pre day)


  • Battery 12V - 120Ah
  • 200w Solar Grade A (tho wondering how long it can last without the need of solar)


macrumors G4
Jul 30, 2003
I think that adding up the numbers won't necessarily relate to real-world battery life.
I would recommend that you test that out before going camping, particularly to check if a 200W solar panel will be enough to both charge the battery, and run the portable freezer.
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