Battery help for ancient Pentax K1000

[cold cathode enlarger]

Hi All
Shocked to discover that I can no longer get a V 400 PX 1.35V battery
All the batteries in Tandy are 1.55V so my first question is, can I get away with one and if so what would the spec number be?

My other option seems to be obtain a portable light meter. I've never used one before and perhps they are as rare as the battery?

Thank you and I look forward to your suggestions
Roger

 

[JohnX]

Bristol Cameras show the battery for sale on their website.

 

[trevorbray]

Plenty of good lightmeter apps for smart phones.

 

[Nikon photographer]

http://www.smallbattery.company.org.uk/sbc_mrb400.htm

 

[Retune]

Doesn't the K1000 just take common, readily available SR44 cells? It's not dependent on mercury cells as far as I know.

Edit: The manual mentions LR44 (the alkalkine equivalent) or G13 (aka AG13, SR44) the preferred silver version:

http://www.cameramanuals.org/pentax_pdf/pentax_k1000.pdf

 

[Mike.P]

Bristol Cameras show the battery for sale on their website.

Bristol cameras show a lot of stuff for sale on their website ... try getting them to actually deliver something.
The four times I have tried resulted in the item suddenly being out of stock.

 

[Forkbeard]

I could be wrong but doesn't the k1000 use the same 'hearing aid' batteries as the Olympus OM1?

www.amazon.co.uk/Wein-Cell-4330210788-MRB-625/dp/B00009VQJ7

 

[Retune]

I could be wrong but doesn't the k1000 use the same 'hearing aid' batteries as the Olympus OM1?

www.amazon.co.uk/Wein-Cell-4330210788-MRB-625/dp/B00009VQJ7

No need. Wein cells are only required for cameras where the metering circuit design depended on the precise voltage of the old mercury batteries. The K1000 will work fine with an SR44 or equivalent.

 

[Forkbeard]

Ah ok, that makes sense.

 

[freecom2]

LR/SR44 is the correct battery for the K1000. No need to mess around with other batteries or Wein cells.

 

[cold cathode enlarger]

Thank you all for your replies
The LR44 and the SR44 both deliver 1.5V. The battery I removed is rated at 1.35V.
Does this difference matter?
Incidentally the manual does not give a volatage, merely states: "Mallory PX-400 or RM-400 R or equivalent"
What was the order of manufacture? Asahi Pentax SP100 came before or after the K1000?

 

[Forkbeard]

It sounds as though the light meter isn't directly dependent on a particular voltage from the battery, because the K1000 has a built in voltage regulator which it goes through first, so anything of high enough power (ie anything over 1.35v) will suffice. So your best bet is the SR44s which hold a level charge over their lifetime and won't dip in voltage with time as do the LR44s.

 

[Retune]

Are you saying you have an SP1000 or a K1000? If it's a K1000, the correct battery is the SR44 or equivalent (see link to the manual above). If it's an SP1000, then you can still use a silver oxide battery because the meter has a bridge circuit that can handle the difference in voltage without changing the reading. For advice on specific batteries that work well in the Spotmatics, see:

https://www.pentaxforums.com/forums...atic-sp-meter-not-responding.html#post3108278