Early Nikon F battery

[cooltouch]

I just bought an early Nikon F -- the one with the non-TTL finder and the little round window? Turns out it takes a PX625 battery -- the old 1.35v mercury that can't be obtained anymore -- at least in the US. Now, I know that there is a 1.5v battery that is sometimes suggested as a replacement, and I know that it will work with cameras that have a bridge circuit to regulate voltage. I don't know if the old F has one, though. So, what I'd like to know is, will the early F work with a modern 1.5v battery and meter accurately, or does it need a 1.35v one? If the latter, because it picks up its positive connection from the side of the case, I'm gonna have to rig up some sort of adapter for my 675 hearing aid batteries. Until I buy one, I guess.

[Esox lucius]

You can use two S76 or A76 or SR44 or LR44 batteries in the prism, metering will work fine.

[cooltouch]

[Esox lucius]

Oh, I see. Those metering prisms aren't too picky about the voltage. Try this one, it seems to be a dirt cheap solution with an adapter ring that enables the modern, smaller size battery to be fitted in that battery slot.

http://www.paulbg.com/Nikon_F_meter_batteries.htm

[cooltouch]

Yeah I know about him.

He's a good guy. I emailed him and asked if I could buy just the adapters without the batteries, cuz I can buy 30 of those batteries for $10. I even asked about quantity discounts because I told him I had about six cameras that take that battery (wasn't exactly sure, still am not).

He said sure, no problem, he'd sell the adapters by themselves and we could probably even work out a quantity discount.

So, yeah, he's a good guy, and I'll definitely order some of his adapters.

Those little batteries he includes are the same ones I use -- they're 1.4v zinc-air batteries. Don't last as long as the mercury ones, but they have a similar discharge profile. Only drawback to them is they don't handle cold weather very well at all.

What I did for this camera, though, was I got a piece of household wiring -- pretty sure it's 12 gauge, which is a measurement system that's used in the states, and if it isn't used in Europe, I have no idea how to translate it over. It's solid-core copper wiring, roughly 2mm in diameter (just the copper). I cut off a piece if it, stripped off the insulation, and bent it into a circle. Formed the circle around the 675 battery, then tried it out in the compartment. It just barely fit, requiring a bit of judicious pushing here and there. But I got the angle of acceptance restrictor back in place, and zam! The meter's working.

Now if it isn't picky about voltage, as you say, then I'll just try one of those 1.5v replacements also and see how it works out.

[Esox lucius]

I think none of those batteries designed to drain slowly tolerate cold weather very well? My FM2n meter becomes senile in normal winter weather here in Finland, perhaps because the two SR44/LR44 batteries are placed on the bottom, inside the metal case and there they cool down quickly outdoors.

[walter g]

Px625 batteries are still available. http://24hourbatteries.com/shop/px625battery__32.html

Wein also makes a replacement.
http://www.amazon.com/Wein-PX625-PX13-Battery-Volts/dp/B00009VQJ7

[cooltouch]

[cooltouch]

[walter g]

[cooltouch]

Well, I'm not an expert with the new 625s. But the alkaline ones are not the ones to use because of their discharge rate. There are others, like sliver-somethingoranother or lithiumwhatever that have better discharge rates, from what I understand. But they're still all 1.5v.

Now, some of the old cameras can use them without any adjustment. Like Pentaxes for example. From what I've read more than once, the old Pentax cameras have a bridge circuit that takes care of this problem regarding voltage sensitivity. Any other camera that has this sort of circuit will behave equally as well, most likely.

Other cameras, like Canons for example, are very sensitive to the voltage and don't respond well at all to the 1.5v. But 1.4v they can handle okay enough. And I've found, after monitoring my 675s over a period of months, that they seem to drop voltage to 1.35-1.34 and then stay there for a long time before dropping to the point of needing replacement.

I really can't report any problems with my Canons not holding voltage well. If you have a battery that is losing charge quickly, your camera may have a low-grade short causing the drain. Even though a lot of folks have stated on the net that a 675 -- or Wein, far as that goes -- only lasts for about 6 months or so, I've been getting a year or better of life out of mine with my Canons.

If you have a Costco close to where you live, try them. That's where I buy them at $10 per a card of 30. Far as that goes, I've even offered cards of 10 to members here (the cards of 30 are perforated into three cards of 10) at my cost plus postage. Didn't get any responses. But the prices you're finding are about typical for non-Costco prices I find around here. I don't think you have to worry about ordering zinc-air batteries online. They aren't activated until you pull the tab off them.

[koji]

Buy one of these battery adapter, which makes 1.5 volt into 1.35v
and its size is the exactly (almost, slightly thicker) 625 size.



The problem is a bit expensive.
For some cameras, thickness may cause a trouble.
I don't know if you can find it on eBay or not.
I used it on my Nikon F, which was given to my friend. But I got a black
Nikon F later without a meter. (for a collection)

[Nesster]

...somewhere online I'd seen instructions on how to DYI such an adapter, by drilling out the mercury battery

[cooltouch]

[cooltouch]

Yes, the 675 hearing aid batteries are the ones I use. They have the same voltage as the Wein -- 1.4v -- and last just as long, but they're a lot cheaper.

That is eBay Spain, yes? You might try your local drug store/pharmacist, or discount store, but that is actually a very good price. Here in the US, they're typically about $5-6 for a 6-pack at a drug store. But I buy mine at Costco -- a 30-pack for $10.

Anyway, I don't know what the battery chamber looks like in a Petri Racer. If the + connection occurs at the battery cap, then often you can just drop the battery in the chamber and if the cap has a spring, it will hold the battery in place. Else you can use an o-ring or a small piece of 18-gauge wire to take up the slack if necessary. But if the positive connection is made from the side, like the old Nikon F for example, then you need to use foil or a piece of bare wire, or something similar, to insure connection between the battery and the side of the battery chamber.

By the way, if you don't have a manual for your Petri Racer, here's a link to a pdf at Butkus's site:

http://www.butkus.org/chinon/petri/petri_racer/petri_racer.htm

[cooltouch]

Just give it a try, and see what happens. I've found that, in most cases, there's enough tension on the battery for providing a good circuit, that it doesn't move and an o-ring isn't really required.

[Minolfan]

Yes, that is what you need plus some metal thing (ring, copper thread) to get it fitting in the battery compartment.

[philslizzy]

I use PX625a alkalines in my Nikkormat, Prakticas and Chinon. They dont last too long but I take them out when not using them. Never any problems with metering.

I got 6 for about £2 on ebay

edit: Film latitude and processing will absorb any difference in exposure caused by voltage difference.

[Minolfan]

[David]

The adapter link from about 18 months ago now states that he's no longer making or selling the adapters, FYI.