How Do I Decode The Compatibility of Mobile Chargers?

jetblack on 24/05/2021 - 07:23
Last edited 24/05/2021 - 11:21 by 1 other user

How do I decode the compatibility of mobile chargers (is there a good site anyone knows of that explains it)?

The official 25W charger for my phone gives a max of 9V/2.77A but it only came with a 15W charger, while I have an old 18W charger with Max 9V/2A.

Ignoring that charging speeds will differ, can I simply compare the 2 and say neither the amps nor the volts on the old charger exceed what the official charger can deliver, therefore it's OK?

If I'm looking at after market chargers, how do I know what would be fine? The PDO and PPS acronyms are throwing an added level of confusion into the mix…

• 

  aussiepom on 24/05/2021 - 08:10

  I think (and I am not an expert) that as long as the volts match and the amps is in the right sort of range you should be OK. (bigger A = faster charging)

  https://root-nation.com/en/articles-en/tech-en/en-how-to-cho…

  • 

    Chandler on 24/05/2021 - 20:41

    bigger A = faster charging

    Not necessarily. "Bigger A" can result in faster charging if the device can handle the higher current.

    Fast-charging on most phones also varies the voltage, not just the current. The charger would need to support this, and is usually to a particular specification i.e. Qualcomm Quick Charge (QC), USB Power Delivery (USB-PD). Quick Charge you would want to check the version is correct, whereas USB-PD you would (also?) want to check the wattage is sufficient.

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  avoidfullprice on 24/05/2021 - 08:35

  +2

  Ignoring that charging speeds will differ, can I simply compare the 2 and say neither the amps nor the volts on the old charger exceed what the official charger can deliver, therefore it's OK?

  If you ignore charge speed, all USB charging capable phones will charge slowly at 5V/0.5A based on the old USB spec. The charging protocol would negotiate higher power rating depending on the charging protocol of the phone and the charger.

  So for quicker charge speed, step back and Look at your phone. What is the make and model? They will determine the charging protocol relevant. Good guide is https://en.m.wikipedia.org/wiki/Quick_Charge

  • 

    Krankite on 24/05/2021 - 08:44

    +2

    TLDR; It's complicated but you won't damage your phone unless you are using a cheap chinese knock-off and get unlucky.

    • 

      avoidfullprice on 24/05/2021 - 08:56

      +1

      Oh gosh, some of the "genuine" eBay ones melt the plastic covering! The safety risk we take by paying only fraction of the actual genuine charger.

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  AndyC1 on 24/05/2021 - 08:59

  You are better to google "phone charging standards explained" and read up your self as allot of people do not know how they work due to the technicalities of the standard and implementation.

  For example I know of devices that work on some fast chargers, but not on others due to the hardware interfaces not adhering to the standard correctly….

  • 

    jetblack on 24/05/2021 - 09:29

    It blows me away how bad the 'standards' for USB-C are getting. I've got a bunch of cables but it's virtually impossible to know what each is rated for, with the wrong cable easily making a good charger redundant.

    For the most part I'm really just concerned with not screwing up my battery life, while getting a decent charge rate (not necessarily fastest rate)

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  trongy on 24/05/2021 - 09:04

  +3

  Modern phones communicate with the charger and negotiate the optimal voltage and current that both are compatible with. They do this by following the USB Power Delivery (USB-PD) specification. There's also a proprietary standard called Quick Charge from Qualcomm and Apple used to use its own charging protocol for its devices and chargers.

  If your phone and charger and USB cable support USB-PD, you won't have to worry about damaging the phone even if you connect a 65W charger to your phone. If your phone doesn't support USB-PD, but does support QC 3.0 for example, look for a charger that supports the same communication protocol.

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    jetblack on 24/05/2021 - 09:30

    Very helpful response, thank you!