USB to mains power???
Author
Discussion

audi321

Original Poster:

6,176 posts

243 months

Monday 14th December 2020
quotequote all
Hi all. Does anyone know if it’s possible to buy an inverter which would take the 5v output from a USB power bank and invert it to 220v?

I want to power my laptop on site and it only has a mains power cable, but I have a fairly good USB power bank.

Thanks all.

Edited by audi321 on Monday 14th December 23:19

CoolHands

23,607 posts

225 months

Monday 14th December 2020
quotequote all
Yes if you’re 5v puts out about 100amps laugh

SpamDisco

394 posts

154 months

Monday 14th December 2020
quotequote all
Look up something like a "Power Oak", all in one inverter and battery.

drdino

1,330 posts

172 months

Tuesday 15th December 2020
quotequote all
What laptop?

audi321

Original Poster:

6,176 posts

243 months

Tuesday 15th December 2020
quotequote all
Ok maybe USB won’t wash then lol. I’ve a load of 18v Makita batteries which are always fully charged so is there a way of getting 18v to an inverter then?

colin79666

2,224 posts

143 months

Tuesday 15th December 2020
quotequote all
Again, what laptop?

biggiles

2,176 posts

255 months

Tuesday 15th December 2020
quotequote all
USB won't have enough power to charge a laptop.

If you drive to your site, then it's easy to get an in-car charger for any laptop.

Your laptop battery may well last half a day (depends what you are doing). If that's true, and you can charge overnight, buy a spare laptop battery.

What are you trying to do with a laptop, on a site with no mains electricity (240/110v)?

audi321

Original Poster:

6,176 posts

243 months

Tuesday 15th December 2020
quotequote all
It's a Dell, but it's not just a laptop, I would like to have mains power for other things too. I just like the idea of being able to power things on site lol.

I like the idea of these power generators, but are they noisy?

https://www.amazon.co.uk/NOVOO-Portable-Generator-...

sjg

7,682 posts

295 months

Tuesday 15th December 2020
quotequote all
audi321 said:
It's a Dell, but it's not just a laptop, I would like to have mains power for other things too. I just like the idea of being able to power things on site lol.

I like the idea of these power generators, but are they noisy?

https://www.amazon.co.uk/NOVOO-Portable-Generator-...
Just a big battery and inverter really. No noise. Quite a practical solution if you’ll be away from power, I built a similar thing for camping trips.

Just do your maths on how much current needed and for how long to see if it’s suitably sized for your needs.

Nimby

5,724 posts

180 months

Tuesday 15th December 2020
quotequote all
Cheap inverters usually put out ragged square wave AC. This can damage electronic power supplies designed for pure sine wave mains.

audi321

Original Poster:

6,176 posts

243 months

Tuesday 15th December 2020
quotequote all
Ok educate me. Is it Volts x Amps to get the Watts figure?

mercedeslimos

1,889 posts

199 months

Tuesday 15th December 2020
quotequote all
I'd say you're on a hiding to nothing here. I have a 12v-240v inverter for the car for when I've got a power cut etc and have to get things done, and even then it's not the happiest it will power but not charge the laptop.

240v "silent" diesel generator I reckon for your application and get a Tablet that you can charge through a phone charger.

xeny

5,514 posts

108 months

Tuesday 15th December 2020
quotequote all
audi321 said:
Ok educate me. Is it Volts x Amps to get the Watts figure?
Yes. To get significant power at 5V, you start needing lots of current, which tends to melt things.....

audi321

Original Poster:

6,176 posts

243 months

Tuesday 15th December 2020
quotequote all
xeny said:
audi321 said:
Ok educate me. Is it Volts x Amps to get the Watts figure?
Yes. To get significant power at 5V, you start needing lots of current, which tends to melt things.....
Thanks, so at 18v (from my makita batteries) is that going to be more realistic to power 'things'?

biggiles

2,176 posts

255 months

Tuesday 15th December 2020
quotequote all
audi321 said:
xeny said:
audi321 said:
Ok educate me. Is it Volts x Amps to get the Watts figure?
Yes. To get significant power at 5V, you start needing lots of current, which tends to melt things.....
Thanks, so at 18v (from my makita batteries) is that going to be more realistic to power 'things'?
In theory, yes. But even a 5Ah Makita battery is tiny compared to a 12v car battery's Ah.

If you have a vehicle on site, then far better to use that as a power source e.g. a good "sine wave" inverter, which allows you to power your Makita chargers, laptops, whatever. And you have effectively unlimited power, as you can turn the car on to charge up the battery.

megaphone

11,692 posts

281 months

Tuesday 15th December 2020
quotequote all
Many laptops run on 19v DC, check what's written on your laptop PSU. With the right adaptor you maybe/could use a Makita 18v battery, problem is amp hours, you'll end up charging the internal laptop battery as well as powering the laptop, so it won't last long.

Edited by megaphone on Tuesday 15th December 14:27

Troubleatmill

10,210 posts

189 months

Tuesday 15th December 2020
quotequote all
You can charge your laptop from an invertor that plugs into your car cigarette lighter.

Hard wiring the invertor ( with a seperate switch) to the car battery is better.


colin79666

2,224 posts

143 months

Tuesday 15th December 2020
quotequote all
What laptop specifically? Dell only narrows it down to about 20% of the millions of laptops out there. The reason for asking is some new laptops can charge off usb c, that opens up more possibilities.

TonyRPH

13,546 posts

198 months

Tuesday 15th December 2020
quotequote all
You're all overthinking this. (except megaphone)

Most laptops run of either 19v or 12v.

The OPs Makita batteries at 18v would probably run the laptop for several hours.

All that's required is a suitable adaptor cable (ensuring correct polarity) and that's it.

It's so inefficient to convert from 5v / 12v to 220v and then back to 19v for the laptop,

It the laptop is a 12v model, a car battery will run it for days (assuming the OP is running the CPU at 100% and screen at eye dazzling brightness).

Or simply use one of these: https://www.amazon.co.uk/Laptops-50000mAh-Portable...

skilly1

2,905 posts

225 months

Tuesday 15th December 2020
quotequote all