English

Charger / cable after upgrade from fp1 to fp3

Have just replaced my FP1 with FP3. Not very techie I’m afraid so hadn’t realised I would need to use different cable with usb-c.
Will I be able to use my existing usb wall chargers. Neither of them are listed in the Qualcom lists but if this is just about speed I’m not fussed about that at the moment. I’ve got 2 wall charging plugs which have a usb socket - a Samsung travel adapter with output of 5v and 1A and a Huawei same output. Are they safe to use?

Also I’ve been looking at zillions of usb a to usb c cables. Are there any particular types or specifications I should look for? I get a bit word blind with tech so please can you advise as if I was a 5 yr old?
Thanks, Allan

1 Like

Hi Allan, and welcome to the community forum!

Sure! The ones you describe should work :slight_smile:
You just won’t get QuickCharge with these adaptors. But if it doesn’t bother you, they’re suited.

Be sure to use a USB-IF certified cable (see link for details), as you may have problems otherwise.
Otherwise any good quality cable should work. If you want to use it for data transfer, be sure to check it’s a data cable.

4 Likes

@Alex21 Hi Alex.
Not an FP1 to FP3 upgrade but could you describe in detail how the differences in, fast, normal and ‘charging slowly’ are set by the phone?

That would be difficult to answer without knowing the exact specs of electronics involved (maybe something someone else can add), but in principle:

  • phone tries to communicate with the power supply (e.g. using USB-PD, QC, or a similar communication protocol), and they simply negotiate voltage and current to use; definitely used for Quick Charging, not sure if FP3 uses this outside of QC. Then it’s simply charging as fast as it can. Not sure what FP3 displays (don’t have a QC charger), but my old Samsung actually says “Quick charging” then.
  • phone knows it’s not a proper USB port it’s attached to, but there’s some electronics wired to the data lines (e.g. certain resistors, or just a short circuit) indicating to the phone the charger’s capabilities; I don’t know the details, or if it’s being used widely, but it’s technically possible and has been used for some devices.
  • phone knows it’s not a proper USB port it’s attached to (e.g. dumb wall chargers), it MAY draw power (current) until the voltage drops, and thus knows how far it can go in terms of charging speed. MAY, meaning, not sure if it really does, but I can imagine the phone would at least try to adjust its charging current somehow. Or it doesn’t, and just drops to standard voltages (see below).
  • phone identifies a proper USB port, determines if it’s USB2 or USB3, and selects appropriate current (0.5A or 0.9A); you can observe this behaviour when attaching your FP3 to a USB2 port, it says “charging slowly”, but actually barely charges (or even drops charge very slowly when in use), which is not the case with USB3 connections.

Does that explain a bit/ did that help answering your question?
Sebastian.

2 Likes

Tbvh, I don’t know and I would do here only guesswork. So I think it was better said by @swhcz than I could :slight_smile:
Just adding the phone will also charge slowly between 90 and 100% to preserve the battery capacity.

Really? Because the FP3 has a USB2.0 port, so I don’t see why there would be any difference in charging between a USB2 and 3 cable.

FP may be using USB 2.0 standards for data transfer, but charging is a different story, same port, different protocol, in short. Otherwise you’d only be getting 0.5A out of your charger, which would take your phone to charge for 11 hours or so, I guess…

By the way, that’s a necessity for increasing battery life, pumping power into an almost full battery would heat it up, and heat kills the chemistry in it (or would be dangerous right away, depending on what type of battery you’re charging); hence, slower charge = less heat = longer life / no explosions in your living room :slight_smile:

3 Likes

@swhcz Thanks for the ideas, i should probably ask FP support/tech etc. but it’s good to have some ideas to float around with. Thanks again

thanks so much Allan

@swhcz

swhcz

5h

FP may be using USB 2.0 standards for data transfer, but charging is a different story, same port, different protocol, in short. Otherwise you’d only be getting 0.5A out of your charger, which would take your phone to charge for 11 hours or so, I guess…

By the way, that’s a necessity for increasing battery life, pumping power into an almost full battery would heat it up, and heat kills the chemistry in it (or would be dangerous right away, depending on what type of battery you’re charging); hence, slower charge = less heat = longer life / no explosions in your living room

Hmm! I thought that was the case but i just bought a FP IF cable and I have inconsistent results. a) initially i had a slow charge from a 2.4A Belkin USB when at 36% then another time b) using a dumb car 12v/5v adapter at 1A it charged at full rate in 3hrs with no slow charging.

Another thing is given the battery is only 3Ah (3000mAh) it should charge in approx 6hrs plus from the old 0.5A USB2 yet I have

I also have very consistent results with just dumb chargers (I don’t own anything else), but as soon as charger and phone need to negotiate, I can imagine there’s room for errors.

Careful when doing the charging-time maths, consider three things:

  • your phone is running while it’s charging, either in full operational mode, or at least in “charging mode”. That needs power, too, and the abysmal charging times with just 0.5A connected are due to power needs of the phone itself
  • there may (will?) be some loss, the 0.5A may not even fully reach the battery due to, i don’t know, probably laws of thermodynamics
  • since the charging is coltrolled by microcontrollers, they (next to needing power themselves, see my first point) may cut the charge due to whatever reasons (temperature, charged percentage, voltage), depending on their charging curve. We’ve already mentioned the slow-down at 90% charge, that’s one example.

But, rule of thumb, a proper charger should fill up the phone zero-to-hundred in a few hours, I’d say.

Sebastian.

1 Like

@swhcz I agree with your notes, so thanks.