You can stay connected while off-grid for long periods of time without electricity with a high-capacity lithium Battery. It can be used in place of a generator but provides cleaner power at a lower price. In the case, you need to work or you are running something important off your computer while off-grid, can you rely on a 200Ah battery?

Power for a Computer

The most important factor in choosing the right solar power is to match the supply to the wattage of your computer. How much power a computer needs depends on what components are inside your computer, including the processor, graphics card, and hard drive. 

Older models used up to 300 watts and the new high-performance desktop computer uses around 200 watts of power. So how much solar power will you need for a 200-watt computer? 

We take you through the numbers.

Computer Watt-hours requirements

Electrical energy is measured in Watt-Hours. The length of time the computer operates determines how much power it uses.

Watt-hours take into consideration the number of hours you will be running your Computer. 

To calculate Watt-Hours you multiply the Wattage of the device or appliance and multiply by the number of hours you use the device. 

Watt-Hours = Watts X Hours 

If you want to use a computer for 1 hour, you will need 200 Wh of energy. 

This number will help us determine how many solar panels we’ll need and the number of batteries as well. 

How Many Amps does a Computer Draw

A 200-watt desktop computer will need around 1.67 amps to run when using it from the standard 120V outlet. This is the number of amps that it will be drawing from the inverter. Depending on the DC voltage of the inverter you can calculate the number of amps the desktop computer will be drawing through the inverter.

In order to get the amps the inverter will need from the battery to run the TV you will need to convert the Wattage to Amps via the voltage of the battery bank. The voltage in a battery bank is usually between 12v and 24v depending on how you wire the system. 

200Wh/12v = 16.67 Ah 

You’ll need a battery bank that can support 17 amps in one hour for a 12v system. 

How Many Amps Can a 200Ah Battery Support?

Amp-hour rating in batteries gives the charge in amps that can be drawn from a battery over a particular time given in hours.

A Deep Cycle Battery battery is intended to produce the charge for a long period of time like 20 hours. So for a 200 Ah battery, it should produce at least 10 amps over a 20-hour period. 

However, you can go higher or lower depending on the appliance you are using.  Deep cycle batteries are recommended to be discharged at 20% of their capacity so for a 200 Ah battery the max discharge per hour would be 40 amps meaning it can last 5 hours.

How many watts can a 200 Ah Battery provide?

You can use the following formula to determine how many watts can be drawn from a battery.

Watts = Volts x Amps

So if your battery is 12v and has a 200 Ah capacity, then you can draw 2400 Watts from it. This is for the full battery cycle. With the 40 amps max draw it means you can get 480 watts max per hour. You can push this to 50 amps or 600 watts per hour with LiFePO4 batteries. 

How Long Will a 200Ah Battery Run a 200-Watt Computer?  

Our 16 amp consumption is within the safe parameters of 40 amps or 480 watts per that the battery can provide. It actually can deliver more than this. 

So with 2400 watt-hours available. How long will it run a computer 

2400/200 = 12 hours

Because of efficiency losses and the fact that you can fully discharge a battery, this will come around to around 9 hours. 

You can actually add other appliances like a TV to the battery bank. If you don’t need to use it for as many hours and you also have a source for recharging the battery.