there have a solution posted at Ainol forum and this method are from AML engineer , it seem can fix the 100% battery problem, hope this can help.
Offical link here http://bbs.ainol.com...&extra=page%3D1
Step 1. your tablet must be rooted.
Step 2. get any Terminal command line apps from google play
Step 3. in the Terminal apps type "su"(without quote) and [Enter] change user to root, then type the following command :
echo B8 > /sys/devices/i2c-2/2-0034/axp20_reg
Press [Enter]
echo B820 > /sys/devices/i2c-2/2-0034/axp20_reg
Press [Enter]
Step 4. at this time you can reboot your tablet and the battery will run down to 5%, then you can try to full charge your tablet to see the problem is fixed or not.
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ONLY do the following Step 5 to 6 if you still got battery stuck after Step 1 to 4
Step 5. if the problem still exist, then open the Terminal apps again and type the following command :
echo 08 > /sys/devices/i2c-2/2-0034/axp20_reg
Press [Enter]
echo 0800 > /sys/devices/i2c-2/2-0034/axp20_reg
Press [Enter]
Step 6. reboot to take effect.
PS .
1. let your battery nearly completely discharge (for example watch some movie or play games to run out the battery), it may help to more accurate the battery percentage
2. this method are reset PMU and the softare accurate parameter, the battery will go down to 5% after reboot , no need to worry, charge up the battery to 100% is ok.
3. Aurora 2 and Elf 2 can use this method to fix the battery problem, it seem Fire and Mars can use this method too, but the path maybe different.
4. Some users in Ainol foumr say that this method works, but I haven't try it yet, because I used the flash rom method to fixed my 100% battery problem.
