1uke_
Posts: 74
Joined: Thu Jul 07, 2016 9:19 pm

Is it OK to use a 6 port usb desktop charger to power multiple pis?

Fri Aug 30, 2019 4:39 pm

Hello,

I have fallen in love with the Pi and use it to power multiple services on my network, but I find I am fast running out of plug sockets.

I wondered if it is safe to use a 6 port usb desktop charger to power multiple pis? They plug directly in to a wall socket.

Here is a couple of examples of the item I am talking about

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rpdom
Posts: 15574
Joined: Sun May 06, 2012 5:17 am
Location: Chelmsford, Essex, UK

Re: Is it OK to use a 6 port usb desktop charger to power multiple pis?

Fri Aug 30, 2019 4:44 pm

It's difficult to say.

By definition "chargers" don't have to supply a stable 5V at the rated current. Most battery powered devices will charge from anything over about 4V and it doesn't need to be very stable.

The Pi needs a steady supply at between 4.75V and 5.25V. Which is why most people will recommend using something classed as a Power Supply instead of a Charger.

You may have success with those devices or may not. It is hard to say.

W. H. Heydt
Posts: 11064
Joined: Fri Mar 09, 2012 7:36 pm
Location: Vallejo, CA (US)

Re: Is it OK to use a 6 port usb desktop charger to power multiple pis?

Fri Aug 30, 2019 4:51 pm

In addition to what was said above... The device needs to be able to supply 5v at the desired current (3A for a Pi4B, 2.5A for a Pi3B/B+, etc.) at the same time. Don't just go by the single port maximum. Check the power rating for the whole unit. To power 6 Pi4Bs you want it to deliver 18A at 5v.

drgeoff
Posts: 9915
Joined: Wed Jan 25, 2012 6:39 pm

Re: Is it OK to use a 6 port usb desktop charger to power multiple pis?

Fri Aug 30, 2019 5:12 pm

W. H. Heydt wrote:
Fri Aug 30, 2019 4:51 pm
In addition to what was said above... The device needs to be able to supply 5v at the desired current (3A for a Pi4B, 2.5A for a Pi3B/B+, etc.) at the same time. Don't just go by the single port maximum. Check the power rating for the whole unit. To power 6 Pi4Bs you want it to deliver 18A at 5v.
Those figures include up to 1.2 Amperes external load on each RPI - USB devices and things powered from the GPIO header. If you are not connecting devices which can draw that maximum from each and every RPi, the total PSU requirement can be relaxed accordingly.

However the caveat that chargers are not power supplies still applies.


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