Umi Z charge very slow then fast on 3rd party charger

Kuba

Hi,

I just bought my Umi Z and I noticed that it charges fast on original charger and cable, but extremely slow on my old one, that I keep in the office. I mean extremely slow. like from 0 to 5% in 4 hours! I installed app Ampere to monitor charging current and it varies between 300 and 800 mA. Even at this current it should be muuuuuch faster. Note that that charger charges my old Galaxy S3 full in under 2 hours. I know that cable is ok, as it works with original charger, the charger is ok as it charges my old phone fast. Where is the problem? I tried powered on, off, without sim (yea, it sounds stupid but I've read on another forum to try) Nothing worked. Strangely, once so far, when it was around 10% charged (from zero) it suddenly started charging very fast, I mean normal speed and amprere showed current level over 2000mA. On the same 3rd party charger. I have to admit I was trying different things, off, on, powering on/off with and without cable/charging so I can't remember in which situation it suddenly shut off, but it did.

so, have you seen anything like this before? Is there any logic behind this that I'm not aware of? Maybe fast charging kicks in only when charged 10% during full moon? ;-)

I'd appreciate any response from Umi support as well. Guys, it's curious case. Any further troubleshooting you could suggest?

thanks
Kuba

Kuba

Quick update.

I managed (I hope) to reproduce fast charging sequence. I powered the phone off - no change. I remove charger for few minutes and plug it back in. At that time battery was charged to some 5%. Next time I looked it was 21% and going up fast as it should from the very beginning.

Summarising, first 5% took 6 hours (including my on/off, plug/unplug tests), I hope remaining 95% to complete in under 2 hrs. What the heck? Any ideas?

Kuba

another quick update.

I turned the phone on when battery was at 21% and charging. Unfortunately it stopped charging. Half an hour later it's still 21% and I didn't use it, no hungry apps in the background.

Kuba

yet another update

I did alternate power on/off monitoring charging speed and noticed that it charges fast only when powered off. Looks like charging speed is limited by electronics or software. Is it bug? Or maybe UMIdigi intentionally prevents use of 3rd party chargers? Support Team, any ideas?

MarcinP

Kuba replied at 2017-5-23 22:04
yet another update

I did alternate power on/off monitoring charging speed and noticed that it charg ...

Proper charge for Umidigi phones support quick charging needs to be supporting pump express system 5/7/9V 1,65A and 12V 1.25A. So if you using qualcomm charger which is supporting your Samsung will not work correctly in Umidigi phone. Also quick charging could be limited by system at the start and from around 80% to prevent battery damage.
Any battery monitoring apps could not support correctly this latest phones.
If you still using android 6.0 you can open dialer and type in *#*#3646633#*#* you will be transferred to engineering mode - hardware testing - power - charge battery and in ADC you will get charging voltage and FG charging current. Of course you need minus current used by phone while screen is on etc.

Kuba

Hi Marcin,

Thanks for your reply and the info.

There are two aspects of it:
1. charger.
This is not original Qualcomm for Samsung. I bought it separately to have good charging speed for old phone and this is the reason I stick to it now. It's dual port Polaroid with spec (also attached): 2x5V , 2A, . So the charger itself meets the basic requirements and works fine, charging fast, when the phone is powered off and battery over 5%
2.Phone software/hardware
Something throttles charging when powered on. This is a mystery. However, I noticed strange fact that may resolve it or at least put us into right direction in further troubleshooting.
When phone is not charging, FG current consumption is 4mA. When I plug charger in it goes up to 500mA. I will check this reading with original charger when I'm at home tonight, but so far take a look onto attached screenshot. Also, I checked it when charging via my laptop. When plugged in, ADC is around 5000mV but FG consumption goes up to almost 500mA, so this is not Polaroid charger's fault. I also tried iPhone charger and FG reads slightly less - 400mA. Looks like all chargers, or charging process itself boost FG consumption.
Does it make any sense?

Also, with regards to initial and final charging that may be slow to protect battery: when I plug in original charger, it charges it very fast from 0% to 100% when powered off. This polaroid one takes 5 hrs to reach 5% then shoot off  and next 95% takes 1.5 hrs. Strange.

Thanks in advance. Dziękuję :-)
Kuba

Medard22

Considering the rather prevalent problem with expanded batteries I would rather stick witch original charger.

Kuba

This is always the safest option. However, out of billions smartphones and tablets out there, only one maker and only one model was really problematic. (apart from separate, extremely rare cases with other devices), so I wouldn't call this problem prevalent, tbh.  And hey, you don't carry your charger on you all the time. Sometimes, away from home, when your phone runs out of juice, you just need to borrow a charger from a friend to top up. This is normal situation. And my phone doesn't allow it (unless I power it off, wait 5 hrs for 5% charge...) Nonsense. I suspect a failure somewhere. I hope it's software/configuration, so I asked a question on this forum rather than returning is straight away.

MarcinP

Kuba replied at 2017-5-24 17:37
Hi Marcin,

Thanks for your reply and the info.

Hi Kuba
Your charger can handle 2A TOTAL whatever this mean by producer. Is this mean that each can handle 1A (1A *1A is 2A) or only one in same time can handle 2A but if two ports are in use then is splitting to 1A each etc. I don't know.
I can definitely tell you that engineering mode is reading correctly current and voltage.
We not saying that you can't use other suppliers chargers but we not taking responsibilities of any damage or incorrect charging time etc. That why every umi/Umidigi phone is supplied with genuine charger and USB wire.
Proper charging voltage and current is at start 5V and up to 0.5 A when rich correct level is changing at 12V and 0,7A up to around 80% then current is slowly dropping.

Kuba

Hi Marcin,

Thanks for explanation and your patience. This aligns with my findings last night - see screenshot below. Original charger is 12V while mine is mere 5V. These are different leagues. I think I'd need to buy a spare high voltage charger for work, or make sure I recharge before battery drops below 5%. Lesson learned and mystery explained. Big kudos mate :-)

Thanks again
Kuba