Computer requirements

[Beavermeadow]

Hello, I want to put a solar system on my van so I can use my computer and some led lights. I need advice as to how many panels, Watts I need to use my computer 5 hers a day. Please see power usage attached. Thank you, Beverly Johnson
View attachment 6385View attachment 6386

 

[Kevin D Pem]

Let's see. I round up. 10amps at 24volts. 240watts an hour. we would be better off if we talked about trading off the computer for one that is more energy efficient. Otherwise we are talking about 5 hours= 1200watt hours. Winter hours, about 5 hours would be a minimum of 500 watts of solar and the system to support them. For hours after the sun sets we take the 1200 watts/ 12 volt if your looking for 12 volt system. This means 200 amp hours of battery, I would suggest lithium for a faster more efficient charge cycle. The numbers are rounded up to the system numbers. 19 volts is the computer voltage and 9 amps of power, the difference is for loss or low solar days. The LED lights don't use enough power to even figure in. Depending on the computer power needed You may have better options. many newer laptops use USB for charging at no more than 5 amps. An example is my samsung pro chromebook. It uses USB type C for charging and holds the charge under light use for 6 to 7 hours. My Lenovo also charges with USB-C. I can charge both as well as Saundra's chromebook and tablet on 100Watts of solar.

Now you can see why when considering solar it starts with efficient equipment first.

 

[Beavermeadow]

I need the computer to rum autocad I can't go with a small one. Ill check me desktop (its newer) to see if it uses less power.

 

[Beavermeadow]

I have a system that has 3 100 watt panels and this battery shown below. How long will I be able to use this lap top?

Solar Specific 100Ah 12V Volt Deep Cycle AGM Battery Rechargeable PV System RV

 

[Beavermeadow]

Thank you for your help.

 

[Kevin D Pem]

I have a system that has 3 100 watt panels and this battery shown below. How long will I be able to use this lap top?

Solar Specific 100Ah 12V Volt Deep Cycle AGM Battery Rechargeable PV System RV

2.5 to 3 hrs at 1/2 charge of 100ah battery. however you will also need to know how efficient the inverter is. Assuming you have an MPPT charge controller you won't have much loss with the charge controller. Because I feel a need to have a cushion so I stick with the 500w minimum. The last person I installed 250 watts, the very next year they had me install an additional 250w. 400w will work but I would not find it reliable If I was trying to work with it. Daytime use and the battery will likely work, I was talking night time use, as that is what most people want.

 

[Beavermeadow]

The lap top will run about 2 hours with its battery. Maybe I can get more batteries for the computer and charge them w the solar system. I wonder if I can get a DC to DC charger to charge the computer batteries.

 

[Kevin D Pem]

Yes you can. You can get a buck converter (dc to dc converter} and feed it with the solar panel directly. Most cheap converters will work with a 100w panel. They can be paralleled if you like and avoid a charge controller if you like. The computer has the BMS built into it.

I used them to charge a 180ah Lithium Ion battery bank I put together once for a slide in camper I built to go across county that I pulled behind a PT Cruiser.

P.S. If you should use such a converter and need help P.M. me.