[ONE Original Android Development] Gawd:
The slow charging issue is very common with the stock LineageOS kernel, and I think nothing has been changed regarding the charging rate in this kernel too. I made a separate post about this issue as many people were facing it, and it includes the fix (few commits). [MENTION=3292224]franciscofranco[/MENTION] can you please take a look at that post and see if you can merge those into your kernel. Again, not all people face this "slow charging" issue, but almost half of the users do. So it would be really grateful of you to look into it. A few kernels have implemented the "fix" and no user faces slow charging after that.

Default screen off charging rate should be around 1.7A-1.9A and screen on should be about 1.1A, but with slow charging issue, some people (including me) face 100-200mA with screen on and no more than 600mA when screen is off. (Only for a small percent of people the charging is on par, for others it is slow, and for some even slower). And the use of "faulty" cable or charger is not the cause, with everything original and undamaged, the slow charging issue prevails (and I don't know why!)

After that it was found that LineageOS maxed the charging rate limit to 1A, and I quote what the LineageOS team member said, "1A is the rated current limit of the SMB charger chip used (from memory). I declined a similar patch in the past for this reason. Seeing it higher shortens the life of the chip and could possibly cause worse problems" (source Reddit) (thanks [MENTION=5411589]giaur[/MENTION] for posting it there) but still some users reported that it was charging at 1.7-1.9A screen off and 1.1A screen on (if I'm not wrong [MENTION=2091002]jhedfors[/MENTION] was one of them to report). So I really don't get this.

If we do some math, assuming that the phone charges at 400mA (or 0.4A) it would take 7 hours and 45 minutes to fully charge the battery (of 3100mAh). Let suppose the phone charges at 1A (since LineageOS decided to max it out at that, and in fully ideal conditions), and that battery is weared, let suppose to 2600mAh, it would still take 2 hours and 36 minutes to fully charge the device.

If it charges as it came with CM11S, at let suppose 1.8A screen off (battery capacity worn out to 2600mAh), it will take only 1 hour and 26 minutes to charge it completely.

(Please note that I've considered that it charges at the same rate at all battery levels, however in actual there's "trickle charging" which lowers that charge rate when the device is ~85% charged. But we can remove this parameter as we have kept the same conditions for all the calculations above)

And if I remember correctly, [MENTION=4841620]Timmmmaaahh[/MENTION] did a test too, and the result was positive with those commits merged, however charging with stock kernel wasn't that slow for him earlier considering some people like me face worse (he was using Resurrection Remix but charging logic is the same as official LineageOS, and with those commits the charge rate went higher)

So if you could just have a look at it, that'd be great. Thanks again. Your work is much appreciated.

(Edit: Thanks [MENTION=7534963]ab123321[/MENTION], [MENTION=4633983]nikhil18[/MENTION] and [MENTION=4800121]Sultanxda[/MENTION])