Google Nexus 4 - Weird battery indicator behavior while charging?

[PsyOr]

I've notice a pretty weird behavior of the battery indicator (precents) while the device on charge, few checks - not permanent, though not serious but intriguing.

I'm using the original charger (1.2A UK with EU adapter) with original usb, Stock 4.2.2 no root or anything else. (The device is 1month old, bought from Play UK)
Also I only could check this with GSam Battery Monitor because its have a history chart so I could check the battery percentage at any given time.

On the app there is 'Chart' menu in this menu there is also option to view 'Power vs Precent Chart' what gives you a deep look into the charging/discharging details (Hour/Voltage/Precents/...).

In several cycles of discharging/charging I've notice a strange behavior of the battery indicator (the precentage) while the device on charge, for example - when the indicator went to 82 it goes up to 83 then goes down to 82, then 83 again, 84, 83, 84, 85, ....93, 100.
In other case - while it was on 81 its up to 82 down to 81 up to 82 and continue regular....

I've found that GSam not showing 29% and 58% so no worry about jumps on these precentages.

Another one: 91, 90, 91, 90, 91, 92, 91, 92, and continue regular.... heres a picture for this session:

Marked in red.
I can confirm that the device's screen was off, no activity or any heat (the battery temperature was cold - also another thing you could check with GSam) at the moment of the 'jumping precentage'.

I want to say that I have no problem with the battery, its working great, just bother about this jumpings...I thought its only on GSam app but when I looked at the stock battery chart I could see these jumps also while it charging...
Pretty weird, if you don't have a app that analyze the battery status you'll never notice it....

There is anyone whos using GSam and can check if he also has this behavior (its on Chart->Power vs Precent Chart) especially happens on charging (not permanent, can be at any percentage)?
Also anyone have any idea why is it happens?
How do I know what is a good/bad voltage while charging/discharging, any idea how to identify thing like that?

 

[PsyOr]

UPDATE:
First I've tried this charger on 2 Galaxy S2 devices, charged them and confirm that there is no jumping or other weird stuff...

So I tried my S2's charger (700mA) and done 2 cycles of discharging/charging with it, no jumping or other strange stuff...seems fine.
I guess its something with the OEM charger (which is 1.2A) and the/this kind of battery, maybe its not a bad thing after all... (someone said something about 'pulse charging', donno if its the idea on this behavior).

Anyway - if someone use GSam and would like to share if he experience this kind of things as I've described with OEM/non-OEM charger, it will be great.

 

[PsyOr]

Well after more then month another UPDATE:

Seems it dosn't matter which charger I'm using, at some point/points on charging the precentage will jump/drop randomally it could be only once per charge and could be more then 5 at once charge...
I still have no idea why is it happens, with other devices I never notice this kind of thing.

Again, if anybody could please check it with his own device if you notice this behavior (let the device charge full/almost full and check the graph/chart:
at stock battery you'll notice drop/jumps
with GSAM its easier- you can go to 'Power vs Precent Chart' and notice it as the screenshot that I've attached at 1st post, or zoom in the chart and see if you notice any drop/jumping of the 'linear' line)

Thanks in advence...