Months ago, as a summer storm approached, I began worrying about losing electricity. Though we have 22 panels packed onto our tiny rooftop, that system stops generating when the local distribution lines go down. Well, I wanted to keep working on my laptop and phone, and I needed the internet for that, so how do we prepare? I know, quite a first world problem!

I would need the router and the hub running, plus the ability to charge up the laptop and phone. I don’t store much in my freezer, and figured I’d be fine with candle power for when the house lights went out. 

We planned to use the e-bike batteries we had on hand, so we only needed to invest in an inverter. One of the batteries was rated as 48 Volts 13 Amps, providing us 624 Watts (48 x 13). 

The inverter we ordered was the AIMS Power model PWRI150048S. This inverter would convert the 48V DC from the battery to 110V AC; with 3 110V outlets, 1 USB outlet and max output of 1500 Watts. The price? $286. 

Remembering that Volts multiplied by Amps equals Watts, I began listing my electricity requirements and saw that they were well within the wattage that this inverter could handle. 

  Volts  Amps  Watts 
router 12 4.6 56
hub 12 3 36
laptop 14.5 2 29
phone 5 1.2 6
      127

We could keep the above devices running for almost 5 hours (624 divided by 127). A second battery could double this. Note that the laptop and phone each have their own battery, which we could use for much longer once fully charged. Also, we could conserve by turning off the router when not actually using the internet! 

To compare, I’ve listed some other devices I may want to keep running during a power outage. 

sample devices  Volts   Amps   Watts   hours  Watt hours  Kilo Watt Hours (kWh) 
100 Watt bulb     100 1 100 0.1
40 Watt bulb     40 2.5 100 0.1
9 Watt bulb     9 11 99 0.099
fan, portable 120 0.4 48 24 1152 1.152
TV, 32″ flat screen 120 0.6 72 2 144 0.144
microwave oven 120 9.0 1080 0.25 270 0.27
toaster oven, small 120 n/a 650 0.25 162.5 0.1625
tea kettle 120 n/a 1500 0.25 375

0.375

I hope this helped you think through a battery backup system for your needs. Since this exercise, I’ve splurged on a Yeti 400 with a briefcase panel from Goal Zero. Happy to lend this out within my circle, in exchange for your story! 

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