Phone charger - can I use?

[patlon]

Sorry if this has been covered before, but I have a 5v, 4A charger. Would it be suitable to power the Pi 4b? The separate lead is ‘substantial’.

[Paul Hutch]

Maybe.

It depends on the voltage regulation specs of the particular charger. Pi's need 4.75 to 5.25VDC to operate reliably and I recommend 4.85v minimum at full load to be sure aging in the connectors doesn't cause trouble a year or so down the road.

With phone chargers the voltage versus current specifications are often incomplete, on cheaper models often they are simply fraudulent. Without information on the specific make, model, and series of charger, and the specific model Pi, it is not possible to determine if it will work reliably.

If you are willing to risk having the uSD card corrupted, losing the data on the card, having to start over setting things up, and in a worst case (> 5.25V output) breaking the RasPi, then you can give it a try.

[RaspbianUser1]

Well it depends, most likely you may get the low voltage symbol (the yellow lightening bolt), I would just recommend buying the official power supply from the pihut or your countries similar store, unless you want a cpu with low clock speed, just buy a official power supply or one that is made for the pi 4b, make sure its the 4b though

[patlon]

Thanks, both. It is more about my big drawer full of leads, chargers etc which I don't want to add to, albeit in due course. Am not sure why the recommended charger would be any more 'robust' than one which came with a reasonably Oneplus expensive mobile which is even labelled as a power "supply", rather than "charger". It is labelled "DASH", but that is just the relatively high amperage, I guess?

[FTrevorGowen]

Thanks, both. It is more about my big drawer full of leads, chargers etc which I don't want to add to, albeit in due course. Am not sure why the recommended charger would be any more 'robust' than one which came with a reasonably Oneplus expensive mobile which is even labelled as a power "supply", rather than "charger". It is labelled "DASH", but that is just the relatively high amperage, I guess?

It's not a question of "robustness" a phone charger (even if labelled as a power "supply") has different current loading characteristics because there is a battery to be charged unlike any Pi and may not be able to provide the requisite 4.65V minimum at 3A. It also depends upon the exact type of USB C charger it is and the type/length of connecting cable. FWIW, see the loading effects of two different cables for a known, good USB C charger: https://www.cpmspectrepi.uk/raspberry_p ... .2FCharger .
Trev.

[Paul Hutch]

It is labelled "DASH", but that is just the relatively high amperage, I guess?

That's a tiny bit more data.

From what little information I could find it appears DASH is a special charging system that a OnePlus phone will only activate when using the special DASH cable. It also appears that without the special cable it will only provide 1.5A and it's nominal power out is 5.2V.

https://forums.oneplus.com/threads/what ... it.456017/
https://forums.oneplus.com/threads/dash ... ls.452836/
https://forums.oneplus.com/threads/dash ... on.725990/

Unfortunately that is still way too little information to be certain it will be safe. If I had that unit I'd monitor the output voltage while drawing various current levels and create the missing information. If I didn't have the measuring capability I'd only try it if I was willing to risk killing the Pi.