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[Help] My battery is always at 100%
08-26-2015, 03:16 AM
Post: #1
[Help] My battery is always at 100%
When i plug it to charge, even for one minute when it's at 1%, it immediately goes to 100%. I tried taking the battery out and putting it again and it fixed, but when i plug it again to charge, there it goes to 100% again. And the battery doesn't decrease while i use it, it keeps at 100% the entire time until it goes off.
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08-26-2015, 05:43 AM
Post: #2
RE: [Help] My battery is always at 100%
Same problem here! I'm running firmware 8151.

Spybot.
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08-26-2015, 06:40 AM (This post was last modified: 08-26-2015 06:41 AM by Thomas_Sch.)
Post: #3
RE: [Help] My battery is always at 100%
Maybe the thread title could be changed to "[BUG] ...".

It seems, my Prime does have the same behavior (also FW 8151),
so it could be a severe bug in firmware.

Thanks for the thread!
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08-26-2015, 02:42 PM (This post was last modified: 08-26-2015 02:44 PM by Wolfgang.)
Post: #4
RE: [Help] My battery is always at 100%
Opening an at least for three month closed lower drawer:

Prime one:>
> Hardware Rev A, Software 2014 12 3(6975)
> Battery Symbol: 100%
>true voltage: 3.87V
>
>Prime two
> Hardware Rev C, Software 2015 6 17 (8151)
battery smbol at 100%
>true Voltage: 3.93 V

Charging of both Primes is ok, there is no problem.

I think it's a Brain Bug. Roughnecks will surely start an counterattack. ;-)

HP 33C 34C 11C 41CX 32S 28C HP71B 35s 50g Prime Rev. A, C, D. DM 41X, 42. TI 58C, 59, 74, 92-II, Voyage 200, nspire CX II-T, Sanyo ICC 82D and more
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08-26-2015, 06:33 PM
Post: #5
[BUG] [Help] battery stays always at 100%
To Tim, cyrille, ..:
Do you consider this behavior as an error that should be eliminated?
Thomas
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08-26-2015, 08:49 PM (This post was last modified: 08-26-2015 08:51 PM by Tim Wessman.)
Post: #6
RE: [Help] My battery is always at 100%
Are you describing "When plugged in to a cable, the power shows as having the little lightning bolt on it with a full green background?"

If this is what you are describing, then there is nothing that can be done here. The reason why is that the charging circuitry only reports one of 6 levels (roughly 100, 75, 50, 25, "uhoh-i am really low", "i really mean it, I will die soon"). That last one can mean anything from "you have a few miliseconds, to there is still a minute or two left".

It does not report fine values. It also cannot report anything but "I am charging right now" when it is plugged in. So this is a hardware limitation essentially. Note that when it is plugged in, if you tap the corner there is no percentage shown. This is to try and show a difference.

I suppose I could try to add an animation at some point showing the green bar moving.... but apart from that I don't think there is anything else.

Now the charging can sometimes take a while to report the actual battery level. I think the OS is doing some filtering and without enough time it may still be stuck thinking it is full.

Now if I've completely misread what is being discussed, please correct me so I can understand. Thanks!

TW

Although I work for the HP calculator group, the views and opinions I post here are my own.
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08-26-2015, 09:22 PM
Post: #7
RE: [Help] My battery is always at 100%
Hello Tim,

As i understand the first posts, and my Prime also is working now:
In using the Prime with actual FW 8151 without external power supply the battery indicator stays permenently at 100%, and never decreases to 75% / 50% ...
So we don't have the signal to recharge to Prime timely, it will switch off due to empty battery without indicating low battery.

Charging the Prime does work, but also the indicator is immediately at 100%.

@hook, Spybot: is this description correct?

Many thanks!
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08-26-2015, 09:28 PM
Post: #8
RE: [Help] My battery is always at 100%
That's it, this is exactly what's happening.
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08-26-2015, 10:44 PM (This post was last modified: 08-26-2015 10:45 PM by Tim Wessman.)
Post: #9
RE: [Help] My battery is always at 100%
Did it behave differently with old versions of the firmware for you? If you tap the screen or touch a button will the value change or go down?

TW

Although I work for the HP calculator group, the views and opinions I post here are my own.
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08-27-2015, 02:04 AM
Post: #10
RE: [Help] My battery is always at 100%
Running my own discharging test,
there are now 75% at battery Symbol.
Current voltage 3.76 V

I say: No reason to alert.

@hook:

Try to charge your Akku with smartphone Samsung S3. It's the same.

HP 33C 34C 11C 41CX 32S 28C HP71B 35s 50g Prime Rev. A, C, D. DM 41X, 42. TI 58C, 59, 74, 92-II, Voyage 200, nspire CX II-T, Sanyo ICC 82D and more
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08-27-2015, 02:37 AM
Post: #11
RE: [Help] My battery is always at 100%
I didn't know if this was happening in the previous updates, it's brand new and the first thing i did was update it.
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08-27-2015, 06:12 AM
Post: #12
RE: [Help] My battery is always at 100%
(08-27-2015 02:37 AM)hook Wrote:  I didn't know if this was happening in the previous updates, it's brand new and the first thing i did was update it.

How long did you use your prime previously, (approx. _ hours / _ days with display on?)
what did you do with your prime? (only calculations, also running programs?)
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08-27-2015, 06:58 AM (This post was last modified: 08-27-2015 07:00 AM by Digitaldreams.)
Post: #13
RE: [Help] My battery is always at 100%
Forgive me if wrong...

When new or upon a battery change, the software that determines the battery level needs to be 'calibrated'. In reality it means that you have to leave the calculator on charge for a considerable time EVEN IF IT REPORTS 100%. I'm sure the user manual suggests this. It is not possible to directly measure the charge level of this kind of battery hence an algorithm is used taking into consideration charging current, drain current and past history. As it charges, in the background the software repeatedly records the increasing level as '100%' (hence 'calibrating'). This is why it is often reccomended to leave it on charge for a considerable time when new so that the actual 100% can be recorded.

Tim....similar devices using similar batteries have algorithms that show % levels in increments of 1% both when charging and discharging. I don't see why it can not be implimented here. You could go further and include a 'leave on charge !' Indication if the algoritm senses levels increasing beyond it's recorded 100%...Many laptops also have hidden engineer functions to reset the battery calibration when batteries decay or are changed.

Regards
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08-27-2015, 01:23 PM (This post was last modified: 08-27-2015 01:24 PM by Tugdual.)
Post: #14
RE: [Help] My battery is always at 100%
If I'm not mistaken, only the current is changing during a charging phase while a (constant) voltage source is applied. Thing is that the Prime seems to detect only voltage, which by definition reaches a pick during recharge. An alternative would be to programatically disconnect the voltage source and measure battery voltage to give an indication of charge, not the sure the hardware permits that.
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08-27-2015, 01:55 PM (This post was last modified: 08-27-2015 01:59 PM by eried.)
Post: #15
RE: [Help] My battery is always at 100%
(08-27-2015 06:58 AM)Digitaldreams Wrote:  Forgive me if wrong...

When new or upon a battery change, the software that determines the battery level needs to be 'calibrated'. In reality it means that you have to leave the calculator on charge for a considerable time EVEN IF IT REPORTS 100%. I'm sure the user manual suggests this. It is not possible to directly measure the charge level of this kind of battery hence an algorithm is used taking into consideration charging current, drain current and past history. As it charges, in the background the software repeatedly records the increasing level as '100%' (hence 'calibrating'). This is why it is often reccomended to leave it on charge for a considerable time when new so that the actual 100% can be recorded.

Tim....similar devices using similar batteries have algorithms that show % levels in increments of 1% both when charging and discharging. I don't see why it can not be implimented here. You could go further and include a 'leave on charge !' Indication if the algoritm senses levels increasing beyond it's recorded 100%...Many laptops also have hidden engineer functions to reset the battery calibration when batteries decay or are changed.

Regards

There is no calibration as far I know in that battery indicator. As per the post, the calculator will show 100% before:
  • 8,77 hours of continuous use
  • OR 16.9 days (405.7 hours) of being powered off but with the batteries in place

Tim has already said that there is no granularity in the battery voltage. It is possible to do some trickery, example: show mid-values after some fixed amount of time, but if this is not perfectly implemented it will drive people to another kind of issues and questions.

My website: erwin.ried.cl
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08-27-2015, 02:25 PM (This post was last modified: 08-27-2015 03:10 PM by Spybot.)
Post: #16
RE: [Help] My battery is always at 100%
Thomas_Sch:
That is exactly what I was trying to say, my calculator never shows those 75%, 50%, 25% or "uhoh-i am really low" messages. It always stays at 100%, and after using it for a couple of days, it just turns off (no warnings at all). Showing the 100% icon until it dies.

Tim:
my calculator is been doing the same since I got it, I've already done three OS updates and the situation seems to persist. (right now I'm running FW 8151, HW: A).

Spybot.
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08-27-2015, 02:52 PM
Post: #17
RE: [Help] My battery is always at 100%
@ Spybot, hook, Tim:

Sorry, .. All clear from my side, it was a false alarm (for me!).
I had not tested long enough.
Therefore i started a new test this morning.
Battery indicator is going to 75% and to 50%, after running a little program continous for about 5 hours ongoing.
Checking voltage with "CFO + On" each hour shows the decreasing voltage.
HW: C, FW 8151
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08-28-2015, 06:54 PM
Post: #18
RE: [Help] My battery is always at 100%
(08-27-2015 01:23 PM)Tugdual Wrote:  If I'm not mistaken, only the current is changing during a charging phase while a (constant) voltage source is applied. Thing is that the Prime seems to detect only voltage, which by definition reaches a pick during recharge. An alternative would be to programatically disconnect the voltage source and measure battery voltage to give an indication of charge, not the sure the hardware permits that.
Lithium ion batteries don't show any significant change in voltage until they are almost discharged and then the voltage drops off fairly rapidly. A Coulomb counter would be a better circuit for a more accurate battery fuel gauge. It measures the charge going into or out of the battery instead of the battery voltage and gives a more accurate measure of battery charge with finer granularity.
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08-29-2015, 12:47 PM
Post: #19
RE: [Help] My battery is always at 100%
IF fully charged,, the battery has a voltage of
4,09 V; there is a distance of 0.11V of a really full charged LI-ION.
Not charging up to 4.20V produces more load cycles.

So I had following notices:

4.09V 100%
3.76V 75%
3.74V 50%
3.61V 25%
3.55V 0%
3.48V 0% I Low battery. Please connect calculator to power source

2nd low warning: Critical low battery! Please connect calculator to power source immediately

Calc has gone out, immediately battery voltage metering with extech 520: 3.500Volts.

In addition to John Colvin:

Please take a look to:

http://batteryuniversity.com/learn/artic..._batteries


4.2V 100%
4.1V ~90%
4.0V ~80%
3.9V ~75%
3.8V ~65%


I have a lot of 14500, 18650, 18350 LIO ION protected and unprotected Cells in use for my torches and I have to handle them carefully if I use three or four of them in a 2000 & more Lumens beast.

Here you’ll find a lot of inforrmation:

http://www.candlepowerforums.com/vb/foru...ed891f7e15

@ hook and Sbybot:

Are all 4 pins of battery in touch?. I would open the prime for checking the battery’s and Primes pins.

Regards
Wolfgang

HP 33C 34C 11C 41CX 32S 28C HP71B 35s 50g Prime Rev. A, C, D. DM 41X, 42. TI 58C, 59, 74, 92-II, Voyage 200, nspire CX II-T, Sanyo ICC 82D and more
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08-29-2015, 03:10 PM
Post: #20
RE: [Help] My battery is always at 100%
Wolfgang.
Thank you for that amazing report. I'll have to check on that, I'll report later.

Spybot.
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