Background
I purchased this electric screwdriver in the late 1980's. It was a popular model at the time and was part of a range of screwdrivers that had become affordable for the DIY market. I got great use out of it over many years. Unfortunately when i bought another more powerful drill.screwdriver combination unit this one remained in it's case only getting occasional use. I was looking to do some work in confined spaces and found that the drill/screwdriver combo was not easy to use so i got out 'old faithful' only to find that the batteries would not charge. With Nickel-Cadmium batteries of this age that is not uncommon. I could have gone to the DIY store and purchased a new far-eastern manufactured one for under £10 but i felt my current one was of much better build quality and if the batteries could be replaced it could give many years more service.
To dismantle the screwdriver body all that was required was the removal of two push fit roll pins and a couple of self tapping screws.
All of the internal components can then be easily removed. There is a switch assemble which connects to the battery and the charging station contacts, the motor, the battery pack and the two halves of the body.
Note that the gearbox and output shaft assembly are not shown in this photograph.
The replacement Nickel-Cadmium batteries were not of a standard size. Although the diameter was the same as a standard 'C-size' cell the length was not.
A little investigation revealed that they were what is known as '2/3 C-size' and were available with solder tags from Maplin Electronics in the UK. They cost a few pounds each.
The batteries were soldered together using good quality automotive grade copper wire capable of conducting 6 Amps.
The old and new battery packs can be seen in this picture.
The motor, switch assembly and battery pack were carefully reassembled into one half of the casing and tested.
The second half of the casing and the gearbox unit were then refitted and the unit tested.
For a couple of hours work a perfectly good screwdriver has been repaired and hopefully will give many years of good service. Only the batteries went off to the recycling yard...or in this case the battery recycling bin at the local supermarket.