So I finally made my laptop solar powered. I thought I would share and maybe inspire some others to have a play in DIY solar.
First off, this is not a bit multi-thousand pound installation on my roof, in fact the total cost is around £200 so far. Second, I doubt I will be able to keep up with demand running the laptop off my current solar setup, but still.
I simply bought a 50W panel and put it in the window of my "man cave". A 50 watt panel is about the same size as a kitchen cupboard door. As this room has the PC and all the hobby gear, including light sensitive beer brewing, and the PC monitor facing the window, the curtains are always closed. The panel sits behind the curtains in the sun. Behind a double glazed window the panel produces at most about 30 watts due to loses in the glass.
That panel connects to a solar charge controller (EpEver Tracer A 10Amp) which has (currently) two 12V sealed lead acid batteries, a 26Ah and a 12Ah in parallel. This much is pretty much maintenance free. Just leave it to do it's thing and the batteries will be fully charged and kept topped up (floating).
I originally started small deciding to power all my USB charged devices powered off solar. My ecigarettes and my phone where first. Then I found I could power my desktop headphone amp, electronics bench supply etc, by charging LiPos and Lithium ION 12V packs made out of laptop cells. Basically anything that will run off a 12V battery started to get solar powered.
So to power USB stuff from the solar charge controller I bought a 5 Amp 5V Buck converter from ebay, which has 2 QC2.0 ports and 2 normal ports. This runs directly off the "Load" output of the solar. It is more than capable of charging 4 USB devices up to 5 amps without even getting warm. Obviously the 12V sealed lead acids have no trouble keeping up with this.
My phone has a bug where by if it isn't on it's charger the alarm is about 50% reliable in the morning. So I bought a 22Ah power bank, which I charge off solar and it charges my phone by the bed overnight for a week (still only uses about 50% of the powerbank) and it's then charged off the solar on Friday.
The sun in Northern Ireland however DOES struggle to keep up with this small demand during Jan, Feb and March. It was only when April came around that I started to see the solar batteries topping out. Several times in January I had to actually switch the system off at night as it consumes around 50mA running the solar system and that draw alone was causing the batteries to slowly decline as there wasn't enough sun light to make up for running the solar system itself 24/7.
With many sunny blue sky days in May the solar system was sitting fully charged most of the day, wasting solar power. So I needed something to take the smile off it's face.
The laptop. I bought a 90W car laptop charger. I charged up one of my largest LiPo batteries, a 5 Amp hour 3 series pack. Hooked it up and bingo... solar powered laptop.
The 5Ah pack will run the laptop for about 3 hours. So my usage pattern is watching about an hour of Youtube videos before going to sleep it lasts 2 or 3 nights. The LiPo is then charged off the solar system (using a hobby charger (Accucell 6 80W).
Charging that 5Ah pack every few days has definately taken the smile off the solar systems face, so when the weather returns to gray and boring I will probably have to go back to mains power for the laptop and running it in winter is hardly likely.
What you need:
A panel - Monocrystaline, 50W minimum, 100W preferable if you have the space. £50.
Lead Acid Battery(s) - Sealed if you want them maintenance free and indoors. The bigger the better, must be "Deep cycle" or "Cyclic use", NOT a car starter battery. You can get 100Ah caravan or boat batteries for about £80, but they require maintenance and could potentially leak on your carpet if you don't have a shed for them. £50-80
Solar charge controller - MPPT type is preferred. Prices vary hugely, but I would avoid the cheapest chinese ones and go for mid range on budget. The EPEver Tracer A was £50 and works perfectly.
Laptop car charger - these are fairly generic, just make sure your laptop doesn't have a smart charger interface such as some Apple ones and a few Dells which ID their charger and won't charge off a generic source (cause they are ****s). £15 on ebay.
You might want to use various intermediate batteries as the lead acids for the solar system are not exactly portable and it's best to leave them connected 24/7. You can use whatever you like here, I choose 12V 3 series LiPo and LiIon packs and a hobby grade lithium balance charger. The charger was £40 and the batteries vary from £10 to convert a new replacement laptop battery to 3S packs to £25 for a 3S 5Ah LiPo from an (Chinese) RC shop.
The USB buck converter is around £8 on ebay.
Various wires, connectors etc.
As an additional, though unnecessary add-on I made a monitoring box which connects to the charge controller via it's RJ45 port and consumes the RS485 protocol and sends JSON blobs of data from the solar system over the network to a Raspberry PI I use as my "weather station" and so I can log the data from it and graph it. This was custom electronics using an ESP8266 micro controller. The specs, designs and concepts for this are free if you want them, I will share the thread on an electronics forum to help you if you wish to implement.
First off, this is not a bit multi-thousand pound installation on my roof, in fact the total cost is around £200 so far. Second, I doubt I will be able to keep up with demand running the laptop off my current solar setup, but still.
I simply bought a 50W panel and put it in the window of my "man cave". A 50 watt panel is about the same size as a kitchen cupboard door. As this room has the PC and all the hobby gear, including light sensitive beer brewing, and the PC monitor facing the window, the curtains are always closed. The panel sits behind the curtains in the sun. Behind a double glazed window the panel produces at most about 30 watts due to loses in the glass.
That panel connects to a solar charge controller (EpEver Tracer A 10Amp) which has (currently) two 12V sealed lead acid batteries, a 26Ah and a 12Ah in parallel. This much is pretty much maintenance free. Just leave it to do it's thing and the batteries will be fully charged and kept topped up (floating).
I originally started small deciding to power all my USB charged devices powered off solar. My ecigarettes and my phone where first. Then I found I could power my desktop headphone amp, electronics bench supply etc, by charging LiPos and Lithium ION 12V packs made out of laptop cells. Basically anything that will run off a 12V battery started to get solar powered.
So to power USB stuff from the solar charge controller I bought a 5 Amp 5V Buck converter from ebay, which has 2 QC2.0 ports and 2 normal ports. This runs directly off the "Load" output of the solar. It is more than capable of charging 4 USB devices up to 5 amps without even getting warm. Obviously the 12V sealed lead acids have no trouble keeping up with this.
My phone has a bug where by if it isn't on it's charger the alarm is about 50% reliable in the morning. So I bought a 22Ah power bank, which I charge off solar and it charges my phone by the bed overnight for a week (still only uses about 50% of the powerbank) and it's then charged off the solar on Friday.
The sun in Northern Ireland however DOES struggle to keep up with this small demand during Jan, Feb and March. It was only when April came around that I started to see the solar batteries topping out. Several times in January I had to actually switch the system off at night as it consumes around 50mA running the solar system and that draw alone was causing the batteries to slowly decline as there wasn't enough sun light to make up for running the solar system itself 24/7.
With many sunny blue sky days in May the solar system was sitting fully charged most of the day, wasting solar power. So I needed something to take the smile off it's face.
The laptop. I bought a 90W car laptop charger. I charged up one of my largest LiPo batteries, a 5 Amp hour 3 series pack. Hooked it up and bingo... solar powered laptop.
The 5Ah pack will run the laptop for about 3 hours. So my usage pattern is watching about an hour of Youtube videos before going to sleep it lasts 2 or 3 nights. The LiPo is then charged off the solar system (using a hobby charger (Accucell 6 80W).
Charging that 5Ah pack every few days has definately taken the smile off the solar systems face, so when the weather returns to gray and boring I will probably have to go back to mains power for the laptop and running it in winter is hardly likely.
What you need:
A panel - Monocrystaline, 50W minimum, 100W preferable if you have the space. £50.
Lead Acid Battery(s) - Sealed if you want them maintenance free and indoors. The bigger the better, must be "Deep cycle" or "Cyclic use", NOT a car starter battery. You can get 100Ah caravan or boat batteries for about £80, but they require maintenance and could potentially leak on your carpet if you don't have a shed for them. £50-80
Solar charge controller - MPPT type is preferred. Prices vary hugely, but I would avoid the cheapest chinese ones and go for mid range on budget. The EPEver Tracer A was £50 and works perfectly.
Laptop car charger - these are fairly generic, just make sure your laptop doesn't have a smart charger interface such as some Apple ones and a few Dells which ID their charger and won't charge off a generic source (cause they are ****s). £15 on ebay.
You might want to use various intermediate batteries as the lead acids for the solar system are not exactly portable and it's best to leave them connected 24/7. You can use whatever you like here, I choose 12V 3 series LiPo and LiIon packs and a hobby grade lithium balance charger. The charger was £40 and the batteries vary from £10 to convert a new replacement laptop battery to 3S packs to £25 for a 3S 5Ah LiPo from an (Chinese) RC shop.
The USB buck converter is around £8 on ebay.
Various wires, connectors etc.
As an additional, though unnecessary add-on I made a monitoring box which connects to the charge controller via it's RJ45 port and consumes the RS485 protocol and sends JSON blobs of data from the solar system over the network to a Raspberry PI I use as my "weather station" and so I can log the data from it and graph it. This was custom electronics using an ESP8266 micro controller. The specs, designs and concepts for this are free if you want them, I will share the thread on an electronics forum to help you if you wish to implement.
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Is it to create a consistent reference during switch-over?