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Jolla tablet - battery replacement [answered]

asked 2018-09-03 22:52:15 +0200

jpjolla gravatar image

updated 2018-09-12 02:20:41 +0200

launchpad gravatar image

Anyone know where to get new battery.

JT battery has been deterriating long time and now it has slower down charging too.
New is a must!

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The question has been closed for the following reason "the question is answered, an answer was accepted" by ced117
close date 2018-09-12 19:42:31.190075


Are there replacement instructions ? opening the case does not seem obvious and I would not like to damage it with trial and error. I'm just asking because my tablet has bulged after a small drop and now it has a funny shape so I would like to remove, recycle & replace the battery.

eber42 ( 2018-09-05 08:56:22 +0200 )edit

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answered 2018-09-11 13:30:38 +0200

launchpad gravatar image

updated 2018-09-13 00:50:57 +0200

By last November everything had to go very quick, as the original battery inflated at dramatical rates within 3hrs. The display began to bend while one could actually touch and feel an increasing curvature. Screen areas under higher stress began to fade and whiten. The tablet had to be saved from self-destruction ... So I disassembled the device as fast as I could without having had any chance searching the web for information / hints. While removing the screws, the rear panel literally popped off, as the battery inflated twice to its nominal thickness .....

After researching the web for suitable replacements ( satisfying specs, quality of make and reliability of supplier ) I ended up with a replacement designed for the Acer Iconia Tab 8 - in my case sold by batteriexperten[dot]com :,-3.8V,-4900-mAh.html

Google / Ebay search for "Acer Iconia Tab 8, 3.8V, 4900mAh" will deliver more results / suppliers.

After the replacement arrived it needed to be made compatible to the Jolla device, by reversing the pin order of the battery connector - exchanging both red and black as well as the green and white pins ( using a flat precision tool screwdriver ).

The replacement battery fit perfectly into the tablet. No need to stick it. After discharging it until the tablet shut down I recharged it over a period of about 5hrs with a meter attached. The battery capacity turned out to hold more than 6600mAh by the first charge - about 30% more than specified and almost 50% more than the original battery. Meanwhile, 285 days later, the metered capacity averages around 6000mAh - which still is very acceptable. The tablet plays web radio stations for more than 24hrs, sourcing via WLAN and dumping audio via Bluetooth. The replacement indeed has become a very perceivable upgrade.

The battery capacity reading ( e.g. AIDA64 tool ) never changed from 4450mAh. It seems the tablet does not meter / calibrate this kind of battery information.

No issues with the replacement battery so far, since Nov. 30th 2017 :) ....

Some pictures of the story below - hoping they're useful to you ....

!! NO WARRANTIES !! Recheck within your actual configuration ! Good luck !! :)

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thank you, this looks very interesting !

question : is the Jolla able to correctly communicate with the battery management chip inside the pack ?

e.g.: does it manage to correctly transmit data about its temperature ?

This was a problem when people used HTC battery on the Jolla 1, until companies like Jabatec started producing replacement with a compatible BMS ('s firmware)

DrYak ( 2018-09-12 09:21:05 +0200 )edit

Thanks for the info @launchpad !

ced117 ( 2018-09-12 19:43:09 +0200 )edit

You're welcome @ced117 ! Glad if it will work out just fine for you :) .... Feel free to update / comment if you would have valuable experience worth sharing ;) ....

launchpad ( 2018-09-13 00:09:48 +0200 )edit

Hi @DrYak, refering to your question, the tablet seems not to receive any temperature updates from the battery sensor as I just re-checked it with AIDA64 today: the temperature still reads 23°C as the screenshot from last November above ;) .... The tablet does have problems though in "accepting" the battery if you'd NOT reverse the white and green pins of the connector-piece. If finding some time, I could try to find out more - maybe you're quicker ;) .....

launchpad ( 2018-09-13 00:22:13 +0200 )edit

if you'd NOT reverse the white and green pins of the connector-piece

I wasn't actually thinking that you've botched the connector swapping.

More like, the BMS chip (or more likely the firmware running on it) doesn't quite speak the exact same language that the Jolla Tablet expects (e.g.: "temperature" and "last measured maximal charging capacity" are probably exposed as different I2C registers than expected).

But that's way beyond my capabilities

DrYak ( 2018-09-13 02:32:01 +0200 )edit

answered 2018-09-11 17:32:53 +0200

jpjolla gravatar image

Thank you !!

I ordered one here.

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^ @jpjolla : Glad it helped ! :) Maybe share a note about your experiences then ....

launchpad ( 2018-09-12 02:19:47 +0200 )edit

answered 2018-09-12 18:32:23 +0200

jpjolla gravatar image

Will comment when I have received the new battery.

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An answer announcing a future comment is no good answer. Please remove, or expect some downvotes.

luen ( 2018-09-12 19:57:13 +0200 )edit

Hi @jpjolla,

maybe you're new around here - so I'd be very glad if I could give you a piece of advice, that you usually discuss / comment topics by posting comments via [ » add a comment ] as otherwise the list of "answers" would sprawl out of control ( what in turn would be counter-productive to this site ).

So maybe you would consider copy-pasting both of your "answer-declared" comments into the comment-section of my answer » above .... Then delete your answers here.

The idea behind commenting my answer with your experiences from upgrading your tablet's battery in mind is to verify / refine the reproducibility of my proposal ....

Thank you for your active participation in this forum, I'm glad if I could help and thanks a lot for keeping this community resource neatly structured :)) !!

launchpad ( 2018-09-13 00:04:29 +0200 )edit

Battery received and replaced. With this Battery the Green and White wires needed To he swapped back. No charging if other way around. the battery temperature sensor is working. For opening the tablett, remove the end pieces, under there,there are 4 screws at Top and 3 screws at bottom. THERE IS ONE IMPORTANT PIECE OF ADVICE: REMOVE THE SDCARD FROM DEVICE BEFORE DOING ANY DISMANTLING. I twisted my sdtray ( pins of the board) and no SD is functioning . A I have not used the sd at all, so this is not major issue for me.

jpjolla ( 2018-09-18 20:11:04 +0200 )edit

Ps. regarding the game with comments and answers, I would have corrected it , but the comment from " nitpicker" luen made me keep my original approach. The issue is that when there is 3 messages there is no way some one could get lost , if comment is answer and vice versa. Been around here since I bought jp1, so felt that adding info is more important than hitting the right button ( used Xperia X to comment , browser view is quite small text) ( sorry @launcpad if I am making you feel unhappy, your approach is the correct one , warm and guiding)

jpjolla ( 2018-09-18 20:25:50 +0200 )edit

@jpjolla - by end pieces do you mean the white side panels?

Louis ( 2018-09-30 21:49:36 +0200 )edit

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Asked: 2018-09-03 22:52:15 +0200

Seen: 642 times

Last updated: Sep 13