Mobileread
Can i extend my battery if i do intensive processes( for an ereader) while charging?
#1  Morioh 09-17-2019, 11:22 AM
Hello everyone!
This question has been bugging me for a while and I'm really interested in getting to the answer. I'm in a possession of an android eink reader, been using it for a some time ,and while i'm generally happy with the battery life, when i use it as a tablet/mobile with wifi and even sometimes bluetooth (mostly browsing and opening pages with a lot of animations and dare i say it even watching videos) my poor battery has a hard time dealing and the percentage goes down fast.

From my knowledge generic lithium ion batteries after around 500ish full charge/discharge cycles show noticeable degrading. So for combating this phenomenon an idea came up to me, in which i will do most of the cpu/einkrefresh intensive processes while connected to a charger.
With this i hope that my device will use the power from the power cable instead of the battery.

But here lies the problem, i don't know if tablets/einks are designed to function in that way, or using them while they are charging would only drain the battery even if they are connected to an outside power source resulting in even bigger battery cycle usage.

Since most of the electronics (tablets/laptops/phones/handheld videoconsoles) allow you for an increased performance while charging my theory is probably correct but i'll leave the final answer to the experts here.

Theoretically you could argue that with plugging and unplugging or rough handling and treatment i might damage the power port which will render my device moot, but i'm already covered on this front since i plan to use a magnetic charging cable with a plug and put it on a tablet stand.

Something other i noticed is when you are charging and using electronic devices simultaneously if the power consumption is bigger then the ability of the charger then the battery will start to get used and even negative discharge while still connected to the charger! But this is a most extreme of cases i doubt i'll ever encounter this(benchmarking or 100% cpu usage for long periods) . What about the produced heat? I really don't think think it's anykind of a factor but i've been wrong before.

What do you guys think?
Is this a legitimate way for me to increase the effective hours i can use my device while saving battery cycles so i can use them on reading addictive books.



P.S:
I'm sorry if this is , seemed like the most appropriate subforum to post in.
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#2  j.p.s 09-17-2019, 02:22 PM
It will work normally while charging and there will be a bit less wear and tear on the battery.

I wouldn't want to deal with the cord myself.
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#3  leebase 09-17-2019, 02:42 PM
Use until completely discharged. Charge.

Have an external battery pack for those times you want to read while the charge is happening.
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#4  theducks 09-17-2019, 03:21 PM
leebases advice was the rule when batteries were NiCd. They were notorious for being LAZY (capacity wise) if you did not do full swing usage.

I have never had modern NiMh (common in phones and readers) exhibit that, even when kept 'topped off'

Your charger needs to handle the added load of work and charging.
Using the USB port on a computer is severely power limited and not suitable for this type of usage.
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#5  leebase 09-17-2019, 03:27 PM
Quote theducks
leebases advice was the rule when batteries were NiCd. They were notorious for being LAZY (capacity wise) if you did not do full swing usage.

I have never had modern NiMh (common in phones and readers) exhibit that, even when kept 'topped off'

Your charger needs to handle the added load of work and charging.
Using the USB port on a computer is severely power limited and not suitable for this type of usage.
You are probably right. Old habits

But the "external battery pack" is a real convenience for keeping a device going when the battery is low and you don't want to be tied 3' from the wall outlet.
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#6  theducks 09-17-2019, 04:56 PM
Quote leebase
You are probably right. Old habits

But the "external battery pack" is a real convenience for keeping a device going when the battery is low and you don't want to be tied 3' from the wall outlet.
You got that right!
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#7  barryem 09-17-2019, 08:44 PM
I think it depends on what powers it when it's plugged in, the battery or the charger. I don't have a real answer to that but if I had to bet on it I'd bet that most devices still run off the battery and that the charger is keeping the battery charged. If that's the case you're not accomplishing anything.

Barry
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#8  theducks 09-17-2019, 09:11 PM
Quote barryem
I think it depends on what powers it when it's plugged in, the battery or the charger. I don't have a real answer to that but if I had to bet on it I'd bet that most devices still run off the battery and that the charger is keeping the battery charged. If that's the case you're not accomplishing anything.

Barry
Barry, you are probably correct. Plugging in a USB cord does not interrupt the Battery leads (Remember Battery Eliminators, sold to save your dry cells on your old Boom Box). Your device just charges away at a uniform rate. Device surge draws are made up from the battery.
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#9  AnotherCat 09-17-2019, 11:05 PM
Assuming Lithium-Ion, Lithium-P, etc.

The charge controller in the device is normally managed by the system to provide system current demand first and the difference between that and the charge current available from the external charger diverted to battery charging. So this, for example, allows the device to start even when the battery is completely discharged. In moments of peak system demand if the difference becomes negative, only the extra required over the charger's capacity to meet the system demand is taken from the battery.

The charge controller manages the stepped charge regime as the battery charges and battery float, and may evaluate the charge capacity of the attached charger and, for example, refuse to charge if charge current insufficient or offer a display message that the charger is of low capacity such as many Samsung devices do.

I think this has applied to probably all devices for quite some years now, apart perhaps for some cheaper ones.

A common occurrence where the system uses more energy than the external charger can provide is when using a phone for navigation in a car and the 12v cigarette lighter type charger is an older on (so can only provide 200 or 500mA). In that case the system takes energy from the charger and the shortfall from that from the device's battery - until the battery is discharged.

For many years now I usually run my notebooks when in use with charger attached so that they remain fully charged. I often run tablets and phone sitting attached to a charger for the same reason.
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#10  Morioh 09-18-2019, 11:02 AM
Thanks you for the replies. The subject is now a bit more clear.
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