# Interest group forums > Energy and Resource Conservation Forum > [Opinion] Electric Charge Machine

## Taps

Good Day

I recently purchased an electric charge machine/invertor to charge and use a battery to counter load shedding. Please advise which size of a solar battery can i buy that i can use on 70 watts TV and 2 x 4.5 Watts electrical bulb. I expect at least 5 hrs of battery use.

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## GCE

Hi 
Without knowing input voltages of your inverter  your most important factor when choosing a battery is Depth of Discharge (DOD) cycles . 

Most solar VRLA batteries sit around a comfortable 20% DOD - Lithium batteries around 80% 

With your requirements listed you are wanting 400 VA ,excluding the losses of the inverter which vary according to the make and size,  of battery usage during the 5 hours - 

A 100VA VRLA battery would be borderline and sit at around 33% of DOD excluding the inverter losses - I would use at least 200VA 

Ask the supplier to give you the DOD graph to see what would work best on the batteries they are supplying

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