I got a little inspired by the solar powered EDC post and it made me think about my computing setup. I use a modern smartphone and a higher-end desktop that is almost always on. I also have an e-reader and some ear buds. I often charge the smaller devices with a power bank. It would be interesting to see if I could move my computing from my desktop to a (preferably second hand) laptop and find a means of charging all of these devices without using the electricity from the utility company.
I already have a small 250W solar array on top of my garage with three golf cart batteries. It runs some lights and occasionally charges devices via USB on the controller. The issue is that it is a bit of a hassle to use due to the garage not being well sealed or climate controlled. It’s dusty and there’s grease and other things from my mechanical projects and it’s always very hot or cold depending on the time of year.
The perplexing part of this for me is charging laptops. Inverters are wildly inefficient but I’m not sure of a way to sufficiently charge (or power) a laptop without one. What are some solutions here?
Additionally, what are some solutions for a potentially portable (or luggable, I guess) setup for these devices? Build a battery box myself and keep it charged on the garage array? Pick up one of those larger “solar generator” pre-made battery boxes that are so popular on the big eCommerce sites now? What about small panels I could put in a window or take outside?
I know the energy used by these devices is far less than things like my fridge/HVAC/laundry machines but it’s an interesting rabbit hole for me. Sorry if this has been posted already but I scrolled through a couple of pages and didn’t see a similar question.
Thanks!
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I use two Ecoflow batteries, a smaller 2kAh model and a 4kAh one. I have solar panels on my Garage roof, the big battery lives there. I charge bike batteries directly with the big battery, and use the big one to charge the small one for use in the house.
The setup is expensive overall, but the results are great. The batteries have USB C that can charge laptops and other devices, and the AC outlets are powerful enough for the vaccum cleaner, coffee machine, basically everything in the house that can be plugged into an outlet other than some power tools.
Edit: Actually I haven’t installed the panels yet, I’ve been too busy. When I first posted it seemed like an unimportant detail, but yeah, no. I have been using the little battery for about 18months already with a smaller portable panel that moves around the yard to get the best sunlight, so the details about using the batteries are true. But I’m still unsure how to charge one battery with the other. The AC outlets will work for this, but the conversion losses are a problem, and I’m looking into how to do DC transfer.
The perplexing part of this for me is charging laptops. Inverters are wildly inefficient but I’m not sure of a way to sufficiently charge (or power) a laptop without one. What are some solutions here?
What you want is called a downconverter. It will accept a wide range of inputs e.g. 22-40V and will output the voltage you need. Example. I am powering a small computer from a 48V e-bike battery with one of those.
Check on your laptop power supply what output voltage it has. 19V is common but there are 12V ones as well. You will need to solder a fitting connector. Some can be bought, but more often than not, they cost the same as a second hand supply.
You can always look for a 12V car adapter charger for your laptop. For older 19V input ones (or similar) they are quite cheap and not that inefficient.
Modern laptops with USB-C power-delivery complicate things a bit as they use variable voltage and thus you need a special charger.
About 6 months ago I moved from a big desktop to a laptop with much less compute power. I had to change a lot of my workflow and software because I didn’t realise how much background compute and stuff everything was doing on the desktop.
I do miss some of the features, but overall I feel better about myself and my situation. I feel more in control and aware of what is going on with my hardware and that is satisfying.
I was able to tune the desktop down to about 65-85W usage, but prior to all that, it was pulling like 180W just doing nothing. I found the most gains by turning down my monitor from 100hz to 60hz and turning on eco mode for the CPU in the BIOS. The laptop uses about 10W even under load.
Best of luck with the switch!
Some solar controllers will have USB C out and you can charge modern laptops with that
Otherwise you can get USB C to barrel jack adapters that may work for your DC devices
HTH
