Sarahps33 wrote:
For example my laptop says 20v/2.25a on the charger.
For each device like this I went to this website for a quick calculation: https://www.batterystuff.com/kb/tools/dc-to-ac-amperage-conversion-run-through-an-inverter.html
And I'd turn it into 12v DC - giving me the amp draw.
In the case of my laptop it was converted to 4.14a
I took those amps and multiplied it by how many hours a day I would use it.
The most I'd ever use it in one day would likely be 7hrs.
4.14a x 7hrs = 28.98a
So that tells me how many amps I'd use from that laptop a day, right? Am I doing it right so far? Lol.
The rating is the maximum. That would be high usage such as streaming a movie and charging the battery at the same time.
For the 7hrs use it may only take that power listed for 2 hours to re-charge.
A compressor fridge will be a challenge. May need 500 to 700+ watts solar to be off-grid continuous.
Propane fridge uses very little battery power (~500 miliamps) to run the controls while the cooling energy comes from the propane.
