It doesn't even taste good.

Yesterday, I'm building a DIY battery pack out of cells harvested from old laptops, thinking "Man, I wish I knew someone with an old broken e-bike or something".

Very next day. I go for my daily walk. 1 block from my house, e-scooter on the curb, with a sign that says "FREE". "Sold!" I said out loud, and carried the thing one-handed quickly back home (okay I only made it a few houses before I switched to two hands).

The escooter itself was held upright with zipties, rear wheel was present but not attached, rear tire was blown, and while it did power on and show something on the screen, the throttle didn't do anything, and it was physically sticky (and thus very dangerous). And e-scooters are banned in my town (my whole province really), and they're pretty dangerous, and I'm stupid enough to ride without a helmet, so I decided to scrap the scooter for batteries.

I found 30x DMEGC INR18650-26E, rated at 2600mAh at 0.5C, and rated for up to 3C discharge: https://e-foton.pl/userdata/public/assets/Testy_ogniw/DMEGC-INR18650-26E.pdf

I have no use for a 36v series battery pack or its BMS, so I pulled a single cell out of the nickel stripping and threw it in my tester, set for 2A discharge, 2A charge, 5 cycles, 10 minute rest period between:

https://i.imgur.com/egbT45Z.png

I got just over 2500mAh at 2C. Cell only rose ~3°C at end of discharge curve. Cell dropped from 4.1895v unloaded to 4.0250v under 2A, indicating internal DCIR 82.25mΩ. Datasheet states <25 mΩ(ACIR), but I don't have an ACIR tester, however these DCIR values are very good and well within the expected difference.

TLDR: Got free e-scooter batteries. All my testing indicates they are near-new, in perfect health, and quite safe. 280Wh of energy storage, enough to watch old TV episodes on my phone for the first few days of the American Invasion.

Southern Ontario, Canada, Sept 21 2026

https://github.com/yucandu/ClockV3

MCU

STM32L412K8T6

Display

ST7305 168×384 2.9" MiP LCD ("Memory LCD") @ 0.25hz

Sensors

AHT20 — Temperature & Humidity
BMP280 — Barometric Pressure
DS3231SN — Real-Time Clock
MAX17055 — Fuel Gauge

The AHT20, BMP280, and DS3231SN are powered directly from MCU GPIO pins to minimize standby power consumption.

Power System

30 mAh LiPo battery (Bluetooth earbud battery)
TP4054 charger configured for 50 mA charge current
DFM8001 energy harvesting module
Two 30 mm × 30 mm × 3 mm amorphous silicon solar panels
    Recycled from dollar-store garden lights

Runs at ~150uA avg, according to INA228 coulomb counter (used as poor man's power profiler). Sitting upside down on a desk in regular indoor lighting at night, solar panels harvest ~200uA. Coded entirely for STM32CubeIDE.

Video posted online shows a CN freight train crew halted midjourney near Armstrong, Ont., on July 13 as wildfires burn outside. CN Rail says it has temporarily suspended operations in the area and relocated employees. Ontario Provincial Police say dozens of wildfires in the region have resulted in mandatory evacuations in at least six communities so far.

It was not fun. I learned nothing. But I did beat my old low current hiscore, so that was nice.

Powered by ESP32-4848S040, an all-in-one ESP32-S3 + 4" 480x480 TFT display.

Mama had been gone for 2 days and it went below freezing, I was super worried bout those buns, but she came back this evening! Boy were they ever thirsty.

lil guy poked his head through like the Homer Simpson meme. cutest thing ever.

shot by my sister, 12/29/2025

Ontario, Canada, 12/24/2025

Little fella remembered me feeding him in that same spot all summer, so I gave him a peanut. Then about 30 more peanuts. He/she was hungry.