Good morning everyone!
I have a house in the mountains where I had to have the electricity turned off because it was too expensive; I thought about various alternative sources (photovoltaic, wind, ...) but the problem is that in winter the temperature is very cold and the batteries would quickly ruin.
I then thought: can I use my 20,000 mAh powerbank, take the 0 V and 5 V form the USB port, connect them to the previous phase and neutral wires of the now disused 220 V and power some light bulbs? If so, where can I find 5V bulbs?
You don't, in all likelihood. You could of course make 12V from 5V using a boost converter and then use e.g. automotive 12V bulbs for lighting.
One safety concern this would raise is that you'll be modifying low voltage bulbs/fixtures to plug into regular wall outlets. This is an accident waiting to happen once your cabin is converted back to regular voltage by a future owner, and/or someone gets hold of one of your light fixtures and plugs it into a regular socket with 220V. Having said that...
Let's say you need 5 bulbs of a very modest 2W each to provide some light to your house in the mountains for 6 hours per day when you're up there. 5 * 2 * 6 = 60Wh/day, and your power bank is 20Ah * 5V = 100Wh. Even if it actually gives you the 20Ah advertised (which is unlikely), it'll last less than 2 days.
This is assuming all you need is some light; anything involving electric heating (water cookers, dishwashers etc) is evidently entirely out of the question to begin with.
You're probably better off using some kind of deep cycle lead acid battery. Charge it in your regular home and bring it up to the cabin when you're visiting. Or maybe a small generator if you need more power.
It all depends on how much power you need, for how long, what your budget is etc.
Do you heat the house while you are there? Use the heat to generate electricity and use that to light LEDs. Why would you want to use incandescent light bulbs?
Thanks for your quick response.
Don't worry, I will take all the necessary precautions to prevent the 220 V from being connected while the 5 / 12 V is connected.
From a quick search I found these bulbs https://fr.aliexpress.com/item/4001045941579.html? gatewayAdapt=glo2fra
but I don't know if they are reliable...
However 24 hours of light is more than enough for me, I certainly can't use any other electrical load.
For the powerbank -> home network connection, do I just need to strip a USB connector, take the pins and connect them or do I need some other intermediary device?
In winter it gets to -10°C outside and I don't spend money on keeping the heating on because I only use the house from April to October; I left a memory thermometer inside and it showed - 1°C as the minimum for the past winter
I don't know anything about this, however my problem is also the budget, solar panels and accumulators have a cost that is far from the simple cell phone power bank.
Buy one of the 3W bulbs and give it a try. Your power bank is probably very optimistically rated but will probably give a few nights' light. If that works, populate more sockets with 3W bulbs. Get into the habit of turning the light off when you leave a room.
We carry a foldable solar charger for our power bank, works like a champ for 3-week trips in the wilderness. Powerbank with built-in LED array lights our tent, charges our headlamps, and gives us evening campsite illumination; solar charger cost us around $70 CDN, but that was 3 years ago, and prices continue to drop. Charger can also directly charge headlamps and cellphones(has two type-A USB outputs) on no-power campsites, instead of charging the power bank, then charging the phones/headlamps. You really should look around.
"light what needs lighting" instead of "light up the room" takes some getting used to.
But frankly, if I took my cabin off-grid I'd have to think about it; -30C isn't uncommon there, so batteries would take a beating. Since wood is plentiful for heating, I'd probably just go with a propane stove, small fridge, and a small AC generator for the rest. I know, how Jurassic of me. Welcome to the wilds of Canada. When you do the math for a few weekends per winter, the contribution to global warming isn't much.
Assuming you can get 100% of the power out, a 20,000 mAh battery at 5V can deliver 100Wh. Realistically you might count on half of that. I think if you were to calculate how many Watts of power you want, and how many hours of that power you want between charges, you'd find that's nowhere near enough. You need to do that math before you go any further down this path.
Certainly, for example for the bulbs I linked above they use 5 W, with 2 bulbs turned on simultaneously I would have power for 10 hours.
I would like to ask you, to connect the powerbank to the home network, can I take power directly from the 0 V and 5 V pins?
and a couple of matching batteries. Probably less than $100 all-in -- which I doubt you'll be able to do what you're proposing for-- and will work much better.
