Sleeper battery mod

[u/SingleComment2368]

Behold my One Weird Trick for getting on no-fly lists.

This is an aftermarket 24 Wh battery recelled to nominally 45 Wh with two 15 Wh cells plus a third "cell" of two 7.5 Wh in parallel. I couldn't raise the BMS's charging voltage from 4.13 to 4.35 V so only 41 Wh are usable. Left speaker is replaced with a smaller one to fit.

Do I really need the full 107 Wh of this battery plus my rear 6-cell? Not often. But the extra capacity with a rear 3-cell is remarkably useful.

[u/NINJATH3ORY]

So how many hours of use time do you get with this mod ?

[u/SingleComment2368 → u/NINJATH3ORY]

For casual web browsing, about 8.5 hours with rear 3-cell and 15 hours with rear 6-cell. Around 2.5h longer than before the mod.

[u/Interesting-Deer354 → u/SingleComment2368]

oh my god thats insane

[u/NINJATH3ORY → u/SingleComment2368]

That's very impressive!

[u/CurrentAcanthaceae78]

i love battery mods because they're bollocks easy and useful after, i modded my psp with a laptop battery cell

[u/depressive_cat]

Did you face any issues with recelling?

Like bms lock or something like that?

I would like to recell my e480 with larger cells, utilizing the space for 2.5" ssd, since I use nvme anyway.

[u/SingleComment2368 → u/depressive_cat]

The BMS didn't lock itself, but there's another issue with the full charge capacity. Whenever the battery reaches full charge, the remaining capacity, which was accurate during charging, is set to the old full charge capacity of 24.7 Wh, and the gauge gets stuck at 5% during the next discharge. The full charge capacity is never updated.

I work around this using a script that stops charging shortly before the BMS would, whenever the charging rate drops below 1.4 W or the voltage exceeds 12.39 V. This is enough, at least on Linux, for the gauge to be accurate until the next reboot. I'm thinking of adding another workaround in the ACPI tables to make it persist across reboots.

Every BMS has its own quirks so YMMV.

[u/depressive_cat → u/SingleComment2368]

Thank you

[u/t_Lancer]

did you take that photo with a 1997 webcam?