Help! Battery charging slowly

Help Fairphone 3
39

Hi and thanks. I will have to look into the QC 3.0 issue as I’m running from a 12v system that produces plenty of 5.1v

It may be the case that whereas the QC system not only controls the over charging but without it the phone is at a loss…

The strange this is when I first got the phone it did a 3hr charge and then slow when nearly charged with old cables. Once I bought the FP cables it was similar but now slowing down at 90% etc.

I had read somewhere that proper USBC cables that control the charge have a chip in the cable plug housing.

So thanks for the prod as I can see there are a few things I can look into. Luckily the relatively slow charge is not the most serious issue I have with the phone it was, I hoped, the easiest to resolve :slight_smile:

The question seems to be how the phone demands the current flow and FP have not replied to my question on how the dynamic power unit in the phone works so I can’t make any adjustements to the power supply and I am reluctant to buy an AC power unit and have to convert 12v to 23v back to 5v etc ~ as that requires more gear and more power. So I will stick with what I have until I can learn more.

Thank you again for your input, it’s very thought provoking for me

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40

Further to the above post, so as not to extend it.

Here is a link to Lion battery charging.
How to Charge a Li-Ion Battery Correctly and Safely.

Basically the voltage at the battery is not the issue it is the power unit that regulates the input from the charger be that reduced from 12v DC or 230V ac. The voltage at the battery is likely to be no more than 4.5V (4.4V is standard max )

With some AC chargers (QC 3) they are able to supply up to 20V to the phones power unit, which in turn can convert this to 4.2V with as much as 4A current ~ the maximum out put being 18W.

So you can see why, if you have a QC3 mains charger you would need a good cable to carry 4A at the lower voltage, hence the idea of carrying less current at a higher voltage and then the phones power unit can convert to to the 4A input.

A 3000mAH battery should not be charged at more than 3A that’s 100% in 1 hour, for longevity of the battery it should be a) a little slower and b) only charged to 90% maybe 96% if you want to push it. So charging the FP battery in 1.5 hours would be a quick charge, anything less implies one of the following, a) power source cannot produce 15W, b) the cable or it’s connectors cannot cope with the current if the power supply is low voltage and high current, or c) the phones power unit is playing up due to either hardware or software issues.

So to go over the charging issue again:

Further to get the 3A from a standard 5.1V USB requires a cable that can handle 3A producing a max charge of 15W and would in ideal case take 2 hours to charge, with a poor quality cable this will not work out well.

With 20V from a QC3 unit it only requires the cable to transfer 0.75A to get 15W and in theory would charge a 3000mAh battery in 1 hour.

So as long as the phone power unit is working well the slow charging is down to the cables capacity and the power supplied to it which should be in the range of 20V to 3.6V with power of 18W.

Well I think that is clear enough. I’m writing this on the hoof with no real layout of ideas o I hope this provides some use.

I will edit this over the coming hours/days to make it more succinct

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41

Then, you should know that batteries aren’t build to be charge at 100% every time so they took more to go from 90 to 100 instead of going from 50 to 90. Many suggests keeping it from 20% to 80%, honestly I charge my FP3 from 15 to 20/30 and unplug it from 90 to 95. This is the way to keep your battery nice and happy through the years. I can say to you that I feel this usage improvement in screen time. Al last, cable isn’ t the keypoint during a charging phase, but you must have a right and proper wall charger, plus and very suggested that supports QC3.0. Aukey is a wellknown brand and it costs only 11€. I looked to FP official wall charger but it costs 29€ + 15€ of delivery, and it is not a fair component XD.

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42

I bought my USB charger and cable with the Fairphone and the charging worked correctly, switching to fast charging after a minute or two. Although due to lockdown the charger has not moved from the living room and hardly been used it stopped charging fast just before Christmas. Cannot be damaged!!! Don’t know what to do…

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43

Please, try to toggle plane mode few times, and charge in plane mode, just to see if it have an effect.

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44

Saw the post about airplane mode - was it you? Thanks but I’ve just been toggling and no change. It’s also awkward I can’t see the charging speed unless the phone screen goes to sleep - do you know how to check it when using the phone :slight_smile:

45

Did you tried to then charge in plane mode only ? Sorry, I have no other advice, It was just maybe chance in my case.
You can read my own experience here: [solved] Stuck in "very slow" charging mode

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46

I find if I unplug the phone, cable and charger and move to a different plug then it sometimes works. This morning I have done this five times to plugs that worked in the past and on the fifth time it worked. Frustrating! But thanks for your reply.

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47

The problem seems to have disappeared for me with the latest update (0077).

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48

Lucky you :slight_smile: Not so for me, but I have a ticket in on the issue.

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49

The problem has also been solved for me since the last update (0077)

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50

That sounded like a good and easy advice :wink: but unfortunately didnt work for me. I reset the system but that didnt change anything. Yesterday the phone charged in 7 hours from 20% to 100%…(thats fast at the moment) but now its back on charging maybe 1% in 2 hours. I also tried a new battery…but nothing changed. but thanks for the ideas… :upside_down_face:

51

Be sure to ask for official support before the two years is up.

https://support.fairphone.com/hc/en-us/requests/new

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52

Still charging slow; sometimes FP3 freezes when charging at night; no alarm… months later and still no decent solution.

53

Your initial post of 2nd Jan didn’t state what OS you are using or what version.

On my front, yesterday, out of nowhere the phone started charging at a fast rate 1% per minuite. I don’t know if this is a one off.

I’m using stock Android 10 V0077, since Jan but the issue was there in Oct 20 when I bough the phone.

It’s not a common issue and like you I am hesitant to do a factory reset ~ who knows what may happen then. Software is a complicated set of instructions and this is a unique set of hardware modules, par for the course.

54

I have the normal stock OS. My FP3 also charges fast at times but I could not figure out under which circumstances.

55

I have the same problem as outlined by OP. I am posting this mainly to keep the thread alive.

I have sent a support ticket and with a link to this thread included.

56

Who is OP and therefore what post/problem are you referring to and can you explain your problem in some detail?

What charger and cable are you using?

57

“Original Poster”/“Original Post” or “Opening Poster”/“Opening Post”, so either the user who wrote the first post in the topic, or the first post itself :wink: .

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