| Author |
Message |
    
George
Tinkerer
Username: George
Post Number: 9
Registered: 12-2012
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, April 21, 2013 - 02:36 am: | 
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Hello,
I have a couple of Hasselblad 500 EL/M with the original NiCad DEAC battery. These have not been in service for a while to the bateries are totally empty.
The original power supplies are marked 60mA. They do provide a voltage but don't seem to provide enough current to either charge the batteries or power the camera.
I have fabricated a 400 mA 6V supply which does both. It will charge the batteries a allow the camera to be operated from a mains supply.
How can this be?
Why is the original power supply not working, but my uprated one is?
Thanks for any help,
George |
Glenn
Tinkerer
Username: Glenn
Post Number: 1075
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, April 21, 2013 - 10:38 am: |
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There are a number of factors, which I am sure others here are far more qualified to talk about/explain than yours truly. However from the practical - seen that, done this side of the camp - I have come across many old/unused NiCads of your type that needed 10 times the rated charge to get them to function and hold SOME charge. The outcome being that a few packs eventually appeared to 'revive' and worked on original charger, others only worked with the higher charge rate and eventually died. I just put this down to the natural life span of these cells and the internal aging of the 'chemistry'.
I have come across two chargers when the copper conductors on the output leads were badly corroded and produced very high resistance readings - this interfering with the low charging current. However, I do not think this is the cause of you not being able to work the system off the mains with the 60 mA. power pack. I presume that the cells have to be in place when system is run off mains supply? Thus suspect that it is the high internal resistance of the aged and degraded cells that stop the system working from mains - all to do with how the circuit is configured.
No doubt the more knowledgeable will correct and put me in my place! |
George
Tinkerer
Username: George
Post Number: 10
Registered: 12-2012
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, April 21, 2013 - 02:00 pm: |
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Thanks for the info.
I will leave the batteries to charge for a good while and see if this can get them to work.
Failing that, I might discard the dead batteries and fabricating an adapter from a 9V cell.
George |
John_shriver
Tinkerer
Username: John_shriver
Post Number: 107
Registered: 12-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, April 27, 2013 - 10:35 am: |
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That form factor of NiCd battery just isn't made anymore. I would not recommend trying to buy a new-old-stock one.
Looks like the best deal is the adapter from "Nine Volt".
Website: http://www.nine-volt.com/main/hasselblad-battery-adapter.php
eBay listing (much cheaper): http://www.ebay.com/itm/9V-Battery-Adapter-for-Hasselblad-500EL-500ELM-500ELX-50 0-EL-ELM-ELX-EL-M-EL-X-/320957572411?pt=Film_Cameras&hash=item4aba8fe53b
Also on eBay, from China, is an adapter to use a CR-P2 Lithium battery. Lithium batteries are very long-lived. |
George
Tinkerer
Username: George
Post Number: 11
Registered: 12-2012
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, May 04, 2013 - 09:58 am: |
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Thank you. I made an adapter with a couple of brass pins, a old 35mm film canister and a 9v battery connector.
Works like a dream. |
