Recovering a "dead" lithium battery

[jdurand]

I look at value engineering as bad juju, especially if it's intended to fail in a predetermined MTBUR. (all personally owned human appliances)
In my working days, my management would keep saying "better is the enemy of good enough", as you know, there are engineers with the mental condition, that keep making changes preventing release on schedule.
They got this to work at the price point, that it's disposable.

There's value engineering which every engineer should understand, and there's intentionally designing a part to fail. Now, there may be a safety reason to have one part fail after XXXX uses in order to cause the device to be tossed before something dangerous fails.

Then there's companies like HP (the current, not the old one). They are known for things like automatically tracking the serial number of printer ink cartridges. If you take a cartridge out of one printer, refill it, and stick it in another... the new printer will complain that the cartridge is registered to another printer and may refuse to print. This is carrying things a bit far.

There's also the eternal battle with production departments. There was a time I designed medical equipment, they complained the production units didn't work right. It turns out they had replaced the high price precision parts with ones the guy at the local electronics store told them were a direct replacement. They also gave doctors the special wrenches to open the device because they didn't buy the latching cable connectors I specified and so cables would fall off in shipping. I left them before they killed someone, they did shock at least one patient.

[jdurand]

An extra thought... If you get one of the TP4056 battery charging boards and use that to safely charge the battery. It automatically drops to 10% charge when the battery is extra low and then when it's up to 3V it kicks into higher charge. Get the board that has the battery protection circuitry on it. Then just temporarily connect to a cell and charge it up.

Don't use on anything less than a 1000mAh battery