I have a cheap 14.4v screwdriver. The power supply of this charger with a primitive circuit for 18V, 300ma.
When charging the battery, its heating was sensitive. I measured the voltage during charging and turned out to be 17.5v, which is not very good for ni-cd batteries. With such a strain, they were already fried. I had long ordered on Alik
With a burned-out relay, and I decided to use it to cut off the upper voltage while charging the batteries. Replaced on the relay module, and the housing for
homemade I took from the PSU an old computer.
Installed the module, but the power supply left the same. I installed a car LED light bulb to gently discharge the batteries. On the module, the lower value was set to 10v, the upper one was set to 16.8v. I set the upper value during charging, controlled with a voltmeter.
