Jump to content


Robert Hart

Recommended Posts

For sake of some locals who would like to shoot with some long-expired film stock on a film camera, I have been checking over the CP16R I still have, servicing it and remounting a CP prime lens set to CP-Mount.

I found that the batteries are not exactly in the best state as in mostly dead. However in a surprise, a battery which I re-celled in 2007 still seems to be good. How it will stand up under load is anyone's guess so I have re-celled a dead one. The two I did in 1988 are goneski. That's when I discovered that the original Nicad cells are no longer available. I was able to find a near-substitute in the form of Nimh cells which are very slightly longer and are extremely difficult to fit within the existing NC4 battery cases. 

To be sure the pack will fit again within the dock in the camera body I had to test-fit the battery before I sealed everything up, then to be sure, placed the battery in a lightly secured vise whilst the silicone sealer I use to bind the cells hardened. After bonding the cover on with the same material, I have inserted the battery in the dock whilst the material sets.

The battery cells were only available untagged so resorted to cutting tags out of shim brass and soldering them on. This added length. The thickness of the battery case walls had to be dressed down on the inside faces before the outer faces were restored correct for width. The CP batteries always were a tight fit and the ubiquitous BIC biro pen blue cap with its tail was the most convenient means of getting a stuck battery to shift without injuring battery or camera by simply shoving it into the gap at the conductor pin end. 

I have discovered another problem. All the little plugpack chargers are dead. All initially powered up reluctantly, seemed to work but from go, the small red LED light would wax and wane until after about 30 minutes it went out. The common failure seems to be open-circuit in the transformers. One went "klikk" which sounds like a semiconductor dropping dead rather than a wire going open-circuit which is usually a "bvvvt-t" thing along with smell. The chargers are a fully sealed throwaway unit. The voltage selector switches were set correctly.

One had been taken apart and put together again with Araldite so I was able to gouge out the Araldite, part the case and have a look. All the diodes seem to have become open circuit. There are some really spiderweb-thin secondary wires coming out of the transformer for the charger circuit. Getting the thing apart risks injuring those wires. 

I have rewound Dremel tool field coils but rewinding one of these is out of my league with that gossamer-thin enamel wire. The CP uses a strange choice of voltage, 20VDC. The charger's placarded output is 23VDC at 0.55mA. I have managed to find a small plugpack power supply which has taps for 20VDC and 24VDC at 1A, so for now will make do with those voltages and careful observation of the charging battery. If anyone knows of a suitable present-day alternative charger, I would appreciate advice. 

CP BATT 1.jpg

CP BATT 2.jpg

Edited by Robert Hart
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Create New...