Droid4: identify batterytype to get charger to work for HV

[buzztiaan]

I modified the kernel to just always assume its using a EB41 and charge at 4.35V

1183 mAh with the original kernel after training/calibrating a couple times.
1357 mAh with my modified kernel. (will throw on github soon)

about 15% more batterylife , making my days a lot less 'where's my USB powersource'' ;)

[buzztiaan]

imho -best- would be to have the cpcap-battery.c code actually detect the right battery, and modify MIN MAX voltages and charge voltages accordingly

-afaik- nvmem interface for that is broken atm. @IMbackK might know more?

[buzztiaan]

BE WARNED

13:24:53 < Wizzup> yeah we decided not to do it after we all had several droid4's with batteries as balloons
13:25:12 < buZz> with EB41s ?
13:27:31 < buZz> or as in, accidentally had the 4.35V charging on a normal lipo that wasnt HV?
13:33:23 < Wizzup> no, just having it on 4.35V for prolonged periods seems to really decrease life time of battery
13:33:46 < buZz> oh, right, yeah i assume so, its a battery from 2012 anyway ;)
13:34:26 < buZz> its on 4.35V for almost no time though :P charging voltage is 4.35V but when it reaches that it almost directly declares 100% and drops to ~4.3V
13:37:27 < buZz> maybe i can try charging only to 4.31V instead, see what the difference in mAh will be
14:33:09 < Wizzup> buZz: right but I often keep my d4 plugged in over night
14:33:23 < Wizzup> and then suddenly it's 25% of the time (yeah 6 hr sleep :p) on 4.35V
14:33:41 < Wizzup> in any case, open a pr and we can discuss the best way

I'll clean up my mod and PR soonish

[buzztiaan]

(PR wont be for merging., dont worry, i dont plan to blow up any phone beside my own ;) )

[buzztiaan]

the kernel now seems to try to identify the battery to be 89-500029ba0f73 (as seen on https://github.com/maemo-leste/droid4-linux/blob/maemo-5.18/drivers/power/supply/cpcap-battery.c#L426)

But my two EB41 identify as 89-5000385c064b and 89-50003a31240b

To get to the nvmem contents :

• Be on latest -devel kernel as of 20220808
• Comment out blacklist omap_hdq from /etc/modprobe.d/blacklist-idle.conf
• Grab /sys/bus/w1/devices/89-/89-/nvmem , maybe rename it like i did and throw on a http somewhere if you can

https://space.nurdspace.nl/~buzz/89-5000385c064b.nvmem
https://space.nurdspace.nl/~buzz/89-50003a31240b.nvmem

[IMbackK]

this is on its way upstream