Trying to calculate power draw when recharging battery

[cmartorelli]

I have a BR1000MS & BR1000G and I am trying to calculate power draw when recharging battery. I see the BR1000MS has a battery charge power of 8 watts but it also has a maxim input current of 12Amps. I am trying to understand if it is OK to have both of these UPS on a 20AMp circuit. Now under normal use with charged batteries they both draw under 150 & 225 watts each. Is it as simple as, if the battery charge power is 8 watts the unit will use a additional 8 watts from the wall to charge the battery.

[Teken · Accepted solution]

For a 120 VAC circuit the 80% power capacity is 1920 watts. 

16 Amps X 120 Volts = 1920 Watts

Based on your stated power draw there are no worries about exceeding the ampacity of the circuit breaker.

If APC states the charger consumes only 8 watts to recharge the battery. Then yes just add in the 8 watts to the connected load total. 👍