Battery life expectancy for Pentax 67 ?

I'm beginning to suspect I'm not getting as much battery life as I

should from my Pentax 67. I haven't kept records, but I know I

fitted a new battery only a couple of months ago, and have taken

maybe 10 rolls on the new battery before it died. I'm still

relatively new to the P67, so I'm not sure how much life to expect,

but surely it should be more than about 10 rolls of 120? I've got a

feeling that's about how much life I got from the previous battery

too. I often don't use the metered prism, using my Pentax Digital

Spot Meter instead. I've been using Varta V28PX 4SR44 Silver 6V

batteries, the same ones that fit the spot meter, so at least one

spare suffices for both.

 

I almost always use MLU, and often take exposures of 1 to 10

seconds, so I assume that causes extra battery drain? I believe

there is a modification that can be done to reduce the battery drain

for MLU. Is it an expensive operation?

 

Should I stick to silver, or will it meter the same if I use the

same size battery in lithium?

 

Should I remove the battery between shoots to extend life?

 

Any other suggestions?

 

Thanks in advance for any assistance.

Hi John,

The there are two ways to drain your battery

1) Use MLU lor a long time (10 ~ 20u hours) it happends to me a couple of time that during transport in a bag the MLU switch went-off

I fixed this by glueing a plastic ring around the switch so it is laying recessed.

2) by Not swiching off the prism ( the old ones don't switch off automaically)

 

If you do not abuse rule 1 and two the battery last for decades.

 

Kind Regard Gert Jan

I tried using <b>VARTA</b> batteries once (on a different camera though) and I did

not get the <i>"normal life expectancy"</i> that I usually had with other brands. I'm

not really sure what to make of this because, in the end, all batteries are basically

made the same way (granted we are talking about the same type of batteries; ie:

alkaline vs alkaline or, lithium vs lithium, etc) and should last about the same. In my

case, maybe I came accross a set of batteries that may have spent a long time in the

store shelves before I got a hold of it. <p>For my P67's I got myself some

<b>SANYO 4LR44</b> Alkaline batteries and those little suckers have lasted an

eternity. In the past, I have also used <b>ENERGIZER 544 (Silver Oxide)</b> and

<b>DURACELL Lithiums</b> (I can't remember the model) and all of these have

lasted a good deal of rolls and I have never had any problems with my meters. I use

the MLU on about 90% of my shots (for about two seconds each time) and I also use

the TTL a good deal and, although I have never kept records of how many rolls I've

shot, I'm sure is a <u><b>LOT</b></u> more than 10 rolls. <p>There is a

modification that you can make to the MLU to prevent battery drainage while it is

engaged but, I'm not sure this is something you want to do if your exposures are

about 10 seconds. I have heard that this type of modification is used mostly by

people doing really long exposures (for example when photographing Stars or other

Celestial Events). <p>Maybe you want to try a different brand of batteries first and, if

you still find that you are only able to get no more than 10 or 20 rolls of film from

them, maybe it is time to have an expert check your camera (you may be getting this

battery drainage because of an electrical problem with your camera circuits). If this

was the case you'll be able to extend the life of your batteries by removing them from

the camera but, if this was my camera, I'd rather have it repaired than live with this

inconvenience (which may cause mayor problems in the future). <p>Keep us posted

on your findings!!

Hi John, yes I went through this episode a while ago too. From memory, the better batteries claim to give you something like 150mAH. I've measured the drain on the batteries when holding the mirror up & shutter open on one 6x7 body (not the p67 II) and found it was somewhere around 25mA (if I remember right most of that goes towards holding the mirror up). In other words, a single battery SHOULD be enough to give you about 5-6 hours of mirror-up ( /shutter open ) time. If you were to average even something like 15 sec per shot of mirror up time, you'd think you ought to get at at least 100 rolls.

 

However, I've found pretty variable results myself - but then I do use the TTL prism a lot and although it uses quite a bit less power (about 7mA comes to mind) than holding the mirror up, it's often on for 30sec at a time) and I also do a lot of 1 to 10 min exposures, so I usually don't complain if I get only a dozen rolls out of a battery. Maybe part of the variation is the specific battery type, so trying some others is probably worthwhile for you. How fresh the batteries are when yo buy them will also influnce the battery life. The lithiums will operate just fine too btw, no need to stick with the silver. Another thing to remember is that the battery indicator light is not a good way to determine whether the battery has had it - I've often shot quite a few rolls well past the point where the light stopped coming on.

 

Although you can make up a plate to use a standard release chord to hold the 'emergency shutter release button' to take very long exposures without batteries or use the battery extension accessory, I wouldn't bother unless you're doing really long exposures - probably easier to just find a good deal on batteries unless you're living somewhere remote like Tasmania ;)

Thank you all. Plenty of good info there. I'll keep an eye on it, but take no drastic action at this stage.

 

Cheers,

Hi. I bought my P67 in 1996, second hand. I put a new battery in the metered prism at that time, and it's still going. I have never had the MLU problem described above, and tend to forget that it is battery driven. My Nikon F4 on the other hand...