Need help getting correct battery AH for off-grid
Hello,
I will be making a few off-grid one-day trips and wanted to make sure I am buying the correct battery for my needs. The battery will be a deep cycle AGM. The Amp Hours (AH) I'll need per day will be 20.57 (see chart below for how I arrived at this number).
Does this look correct to you? If so, is the rule of thumb to multiply the needed AH by 2 so as not to damage the battery? That would mean a 50 AH battery would work...assuming my calculations and other assumptions are correct.
The battery would be charged with house current, and the pure sine inverter (600w) would be less than 3ft from the battery, connected with 6-gage wire.
So, will a 50 AH deep cycle AGM battery meet my needs? Thanks!
EDIT: I can't space out the chart. I measure the Watts with a Kill-A-Watt, calculated the Amps (assuming 120V), added 20% to the Amps for each item to account for inefficiency which gives Adjusted Amps, and multiplied the Adjusted Amps by Hours of use per day to give Amp Hours (AH).
I will be making a few off-grid one-day trips and wanted to make sure I am buying the correct battery for my needs. The battery will be a deep cycle AGM. The Amp Hours (AH) I'll need per day will be 20.57 (see chart below for how I arrived at this number).
Does this look correct to you? If so, is the rule of thumb to multiply the needed AH by 2 so as not to damage the battery? That would mean a 50 AH battery would work...assuming my calculations and other assumptions are correct.
The battery would be charged with house current, and the pure sine inverter (600w) would be less than 3ft from the battery, connected with 6-gage wire.
So, will a 50 AH deep cycle AGM battery meet my needs? Thanks!
EDIT: I can't space out the chart. I measure the Watts with a Kill-A-Watt, calculated the Amps (assuming 120V), added 20% to the Amps for each item to account for inefficiency which gives Adjusted Amps, and multiplied the Adjusted Amps by Hours of use per day to give Amp Hours (AH).
Item Watts Amps Waste Factor Adjusted Amps Hours AH
--------------------------------------------------------------------------------
Water Pump 9 0.08 1.2 0.09 22 1.98
6” Fan 15 0.13 1.2 0.15 16 2.4
Laptop 1 80 0.67 1.2 0.8 9 7.2
Laptop 2 80 0.67 1.2 0.8 4 3.2
Hotspot 10 0.08 1.2 0.1 16 1.6
Cell Phone 5 0.04 1.2 0.05 3 0.15
Tablet 11 0.09 1.2 0.11 4 0.44
Lights 30 0.25 1.2 0.3 12 3.6
-------------------------------------------------------------------------------
TOTAL AH: 20.57
