Upgrade Battery on a InfoTMIC X210 M7206/m799ca

 

As we've all noticed, the battery life in the m7206 is terrible. It lasts about 40 minutes out of the box.
It can be improved somewhat by disabling the phone process running in the stock firmware but it is still only 60-90 mins max.

Replacing the battery with a higher capacity model is quite easy and it will give you a massive improvement in battery life.
The battery that I've used in this tutorial is a 3000mAh 3.7V Lithium Polymer. The battery that I purchased is available on ebay,
I can't link to it here as it's against the rules.
I suggest that whatever battery that you fit to it, you make sure that it has short circuit/over discharge protection. This will be
stated on the ebay auction/website that you purchase it from.

Once you've fitted the new battery, you should follow leeh33's tutorial to remove the excessive battery drain caused by the phone
process in the stock firmware.
http://www.techknow.t0xic.nl/forum/index.php?topic=1129.0

After fitting this battery, my tablet lasted 4hrs 15mins of constant use with wifi turned on all the time. This was with web browsing and
playing games. The screen brightness was also reasonably high. Wifi used 41% of the battery life. I would estimate 7 hours or more of
battery life with wifi turned off, more if you turn down the screen brightness.


WARNING: Lithium Polymer batteries are EXTREMELY volatile, so take your time and be careful when replacing it.
Do not accidentally puncture the battery pack, and do not short the wires coming from the battery or the connections on the board.

The battery used in this tutorial is 3.7V. if you use this tutorial for a similar tablet, make sure that the battery is 3.7V and not 7.2V.
The best way to be sure is to measure the voltage between the 2 wires from the battery after it is fully charged. A fully charged 3.7V
pack will read 4.1-4.2V.
If your charging adaptor is 5V, the battery is likely 3.7V. If the charging adaptor is 9V or more, measure your battery voltage to be
sure of the correct one to purchase.


Here's how to change the battery:

Step 1) To open the casing, you need to remove 4 small screws located in the 4 corners of the tablet.
To get at the screws use a scalpel/razor blade or a small flat screw driver to lift the black sticker in each corner of the tablet.
Don't completely remove the sticker because it will be difficult to put it back correctly if you do.
I've marked the location of the screws with yellow dots in this photo:




Once you have removed the screws, use a credit card or a flat blade screwdriver to slide into lip around the edge of the tablet.
Use it to pop the front of the tablet out of it's casing bit by bit, working your way around the edge.

Step 2)  Now that you have the tablet taken apart, you will see this:


You can see in the photo above that the 2 wires coming from the battery are soldered to the mainboard.
WARNING: Be careful that you do not allow the soldering iron to slip when removing these. There was no
visible protection circuit attached to the original battery, so if you accidentally short these to eachother the battery could go
on fire or explode.
The safest way to do this is to desolder the negative(black) wire first and put insulating tape on it, then desolder the
positive(red) wire and tape that also.
The battery is stuck to the tablet with very strong double sided sticky tape. You can peel the battery off or if you you
think that it's putting too much pressure on the screen you can slide a sharp blade under the battery to cut the tape.
If you decide to use the blade, be careful not to cut or puncture the battery!

Now solder the 2 wire's from the new battery on, making sure to get the polarity correct. You can stick the battery to
the old tape, or you can attach it with new double sided tape or silicone rubber if you have it.

Here's a photo with the new battery in place. There's still room for an even bigger battery.
Your can see the PCB that protects the battery under the yellow transparent tape on the right hand side of the battery.




Step 3) Now you need to charge up your new battery.
I suggest you leave the tablet open so that you can watch the battery for it's first charge.
Nothing should go wrong, but it's best to be cautious with any new lithium battery.
Check the battery every so often to see if it is too hot, or for any signs of bulging/swelling. If it does start to swell or get
hot to touch, disconnect the charging cable immediately.
The battery will take a few hours to charge. Once the red charging light goes out you can put the tablet back together.


Step 4) Enjoy your new tablet with massively improved battery life!  :)
Free business joomla templates