Handy little USB chargers with a slight issue
Added 2025-06-21 04:41:21 +0000 UTCAt first glance these little adaptors for most brands of power tool batteries seem a great idea. A USB power supply that simply clips onto a battery for charging a tool, headtorch or phone.
But there's an issue. They do not monitor for low battery voltage, and if the battery can't shut the power off itself then these modules can potentially brick the battery by overdischarging it.
Comments
The voltage drop at 3A load is likely due to the 0.2ohm resistor - at 3A it's dropping 0.6V at toasty ~2W and the boost IC seems to measure across USB+the resistor.
JD
2025-06-21 17:06:41 +0000 UTCI recently switched over to the workzone (aldi) batteries. The nice thing is they usually have built-in protection, wich makes them very nice for Chinese modules with 3d printed housings. I don't know if they are the same Internationally since they vary a lot between different batches.
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2025-06-21 15:53:52 +0000 UTC
