I using Xiaomi T300 for few years already. Everything good. The brush head no need buy original, can buy those no brand alot cheaper.

the charging cradle has a mount for removing the battery, standard by EU, to remove battery, before buang tong sampah

you can replace (solder) the battery also, but throughout my 20 years, the battery bertukar2
from smaller NiCD to NiMH then to larger capacity NiMH (all roughly AA size) to a higher density NiMH (sub AA)

The latest one i have not changed, almost 2 years old, but its running on t Li-Ion, and its the newer version with all plastic body. I dont like the older design with silicone handle since they grow moldy. But the plastic grip is slippery...