I want to power my desktop

[AbdulSubhan]

My beginner project I want to learn and start small,
I have a desktop and a monitor that I'd like to run on small battery and charge them on solar. Point me towards guide that help my case.

See the image attached.
Also I can't read the wattage rating of my PC but the monitor takes 28 Watt hours.

Need battery bank enough to power it after sun hours and recharge the next morning.

Don't care about sunny days.

 

[AbdulSubhan]

**I mean don't worry about non-sunny days.

 

[John Frum]

Assuming 12 volts for a small system.

Step 1 - find how much your wattage your loads require.
This tool makes it easy
https://www.amazon.ca/P3-P3IP4400-Electricity-Usage-Monitor/dp/B00009MDBU

Step 2 - compute for inverter efficiency
My desktop pc and monitor draw about 65 watts @ 120VAC.
65 ac watts / .85 inverter efficiency / 12.8 volts nominal = 6.37254902 service amps

Step 3 - computer for battery capacity
6.37254902 amps * 24 hours a day = 152.941176471 amp hours.

You will need...
A small inverter but the small cheap inverters will have lower efficiency.
More than 152.941176471 amp hours of battery capacity.
A charge source to replenish your battery.
Think of the battery like a checking account.
The loads draw on the battery and the charge sources replenish the battery.

 

[corndog]

That's cool you're using a low power computer. It's the best things you can do when it comes to building a solar kit, is to reduce your needs first. I'd round up to 100 watts for the computer and monitor, but how many hours does it need to run for? If it gets dark early, say 5pm, and you wanted to stay up until midnight, then you'd need to account for seven hours of use after sunset, but really you've lost solar power before sunset, so you need to account for some extra transition time, sunrise as well. I'd say ten hours minimum, which 100 watts over ten hours is 1kwh. That means a standard 12v/100ah LifePo4 battery would probably do what you need, especially since you're probably not using your computer from sunrise to midnight everyday. Double the battery if you wanted to use SLA/AGM.

 

[circus]

That's cool you're using a low power computer. It's the best things you can do when it comes to building a solar kit, is to reduce your needs first. I'd round up to 100 watts for the computer and monitor

Are you sure. I just looked it up and if that's the tower model it could have a 300 watt power supply.

 

[corndog]

Hmm, maybe not? I searched what was on the label, "Lenovo Thinkcentre M92p" and found this:

thinkcentre-m-series-tiny

Says there's a 65w adapter, but perhaps there are variants of the M92p?

 

[circus]

Years ago a Kill-a-watt meter could be checked out from the local library. Free. Good luck

 

[corndog]

Well, nothing wrong with reading the tag, but it looks like there are bigger models and I see the numbers now on the label. Looks like it's 8a at 120v, so.....yikes. I'd get a different computer. It would save quite a bit of money over trying to build a solar kit to power it.

 

[Bud Martin]

The tag on your PC gives you 100 ~127V 8A = 800VA @100V AC input , 200 ~ 240V 4A = 800VA @200V AC input.
The lower the AC input the higher the current it needs its output regulated.
It is not rated in Watt because of the Power Factor (power supply is not resistive load), if you have Kill-A-Watt meter, it will show the VA and the Watt the unit consumes. If the PF is 0.85 then the Watt will be 800VA x 0.85 = 680W.

 

[AbdulSubhan]

The tag on your PC gives you 100 ~127V 8A = 800VA @100V AC input , 200 ~ 240V 4A = 800VA @200V AC input.
The lower the AC input the higher the current it needs its output regulated.
It is not rated in Watt because of the Power Factor (power supply is not resistive load), if you have Kill-A-Watt meter, it will show the VA and the Watt the unit consumes. If the PF is 0.85 then the Watt will be 800VA x 0.85 = 680W.

that was quite technical But I have a good reason to believe there's no reason that my PC is drawing anywhere close to 680 watts,
it's a desktop with an only CPU and not GPU, well now I need a meter to actually rate it, Thanks everyone for the replies.

 

[Bud Martin]

That is the max rating, so if you do not fill up your computer will bunch of cards then the power consumption will be less and it can easily be measured with the meter.

 

[A.Justice]

My desktop pulls about 100 watts at idle and it's a beast compared to most. It has a 500 watt power supply, but I've never seen it go over 150w, even when running a performance test.

Most desktop computers have extra power left over for the addition of disk drives, cooling systems, and peripherals.

You really NEED to get the kill-a-watt to proceed from this point.