Canon 7S battery replacement Questions...

[mjm6]

Greetings folks,

I have a Canon 7S that supposedly has a functional meter, but I don't have a battery to test it. I'm going to go out and try a 1.5 volt battery to see if the meter responds at all. I presume there is enough overhead in the system that the overvoltage won't be a problem, is that correct?

But my question really is, does the 7S have voltage regulating circuitry, or do I have to get a battery voltage adapter (or have the camera modified) to get accurate meter readings (assuming the meter is anywhere near working properly)?

On another note, I have tried to do searches in the archives for things like 'Canon P' or 'canon 7s' or others, and the search engine rejects the 'P' and '7S' as words with too few letters. Since there are a lot of cameras that have short labels like that, is there a way to do a search on the archives to get a reasonable set of hits on a search like 'Canon P'?


---Michael

 

[jlw]

I didn't have any luck with the O-ring technique -- couldn't get the contacts to line up correctly for some reason. Maybe I didn't have the proper O-ring...

...anyway, eventually I splurged to the tune of $30 and got an MR-9 adapter, which works great and allows me to use a silver-oxide battery.

 

[jlw]

On another note, I have tried to do searches in the archives for things like 'Canon P' or 'canon 7s' or others, and the search engine rejects the 'P' and '7S' as words with too few letters. Since there are a lot of cameras that have short labels like that, is there a way to do a search on the archives to get a reasonable set of hits on a search like 'Canon P'?

If you type your search term within quotation marks, like this --

"Canon P"

-- the search engine will look for the whole term, rather than splitting it into two separate expressions.

 

[mjm6]

Thanks you two,

I'll try the O-ring method, but I think I would rather have a silver battery in the camera, so I'll probably just get the adapter, assuming I keep the camera.

I assume the best place to get an adapter is from Cris? I'm not aware of other places.

As for searching, I should have known to do that, but I was thinking that using quotes would cause too high selectivilty by rejecting slight variants on how people designate cameras, etc. I'll try it and see how it works.


---Michael

 

[mjm6]

G-man,

Thanks, I'll look him up if I decide to keep the camera.


--Michael

 

[Jason_K]

I didn't have any luck with the O-ring technique -- couldn't get the contacts to line up correctly for some reason. Maybe I didn't have the proper O-ring...

...anyway, eventually I splurged to the tune of $30 and got an MR-9 adapter, which works great and allows me to use a silver-oxide battery.

Where did you purchase said adapter?

 

[jlw]

I got mine directly from CRIS Camera Services, which is either the manufacturer or importer:

http://www.criscam.com/old/mba.htm

There are some web advertisers that list the same adapter, but at the time I bought mine none actually had any in stock, whereas CRIS did.

Incidentally, I've found that the first time you turn on the 7s meter, it still reads a bit high even with the MR-9; from the graphs on the CRIS website, I infer this is because the silver battery's initial voltage is a bit higher. I just left the 7s meter on the battery-check position for about five minutes, and this bled off the initial extra voltage. Since then it's been quite accurate and stable.

 

[Kim Coxon]

Hi,
The adapters John Neal sells are better and much cheaper than the CRIS ones. For a start they will handle a much larger current. I am surprised about needing to leave the 7S for a time. One of the advantages of a silver cell is that they have a very stable output curve. I haven't got a 7S but John's adapters have worked perfectly in all the cameras I have tried including the Canonets.

Kim

I got mine directly from CRIS Camera Services, which is either the manufacturer or importer:

http://www.criscam.com/old/mba.htm

There are some web advertisers that list the same adapter, but at the time I bought mine none actually had any in stock, whereas CRIS did.

Incidentally, I've found that the first time you turn on the 7s meter, it still reads a bit high even with the MR-9; from the graphs on the CRIS website, I infer this is because the silver battery's initial voltage is a bit higher. I just left the 7s meter on the battery-check position for about five minutes, and this bled off the initial extra voltage. Since then it's been quite accurate and stable.