Pentax 645N battery drain

[aris_gerakis1]

Hello, I bought a used Pentax 645N with the normal AF lens in mint condition. It eats batteries like

crazy. One set of fresh alkalines does not last a single roll. Granted, it takes me about three months to

finish one roll, but still... I turn the camera off between uses and I store it at room temperature. Is my

camera defective? The manual is of no help at all.

[kelly_hughes]

Yes, that's a bit fast. <a href="http://www.chrysis.net/photo/pentax/645specs.htm">This page</a> as well as B&H (<a href="http://www.bhphotovideo.com/c/product/145096-USA/Pentax_15722_645N_AF_Camera_Body.html#">here</a>) specify the 645n as lasting 130 rolls on alkaline, longer on Lithium. I think that's pretty overly optimistic, but I'd still expect between a dozen and 50 as a bare minimum. I shoot such low volume with mine, I can't even recall when my batteries go in. Mine would go dead from old age before I'd shoot them all out.

[stp]

Yes, something is wrong with the camera to go through a set of batteries that fast (even over

that period of time).

[dougmiles]

Unusual... First thing I'd look at is the cleanliness of the battery compartment and the contacts therein. Debris between the sets of contacts, for instance, might result in a partial short. Worth checking before returning the rig to the seller, or in to the shop.

[aris_gerakis1]

That is interesting. I notice in the battery compartment two contacts for the batteries, and

two more contacts with no apparent reason for being there, dangerously close to the

battery contacts. What are they?

[danny_wong2]

All the contacts are there to connect all six batteries.

 

Clean the all the contact. What type of batteries are you using?

 

If the battery life is the only issue I would just take the batteries in the holder out when the camera is not in use. Electronics issue could be quite costly to repair.

[aris_gerakis1]

Look at the image. On the top of the battery holder (on the right) there are only two

points of contact. Inside the battery compartment (on the left) there are four metal tabs

(kind of fuzzy). Two of them touch the contacts on top of the battery holder. The other

two do not seem to come in direct contact with current, or do they?

 

The camera is mint, no corrosion. I cleaned the contacts just in case.

 

To test the camera after purchase I used generic alkalines, then switched to Dur4ce11

alkalines. It made no difference, they all get exhausted within the first roll.<div></div>

[danny_wong2]

Aris:

 

Looks right BUT doesn't sound right. Another idea to try is to take all 6 batteries out of the holder and give the holder a good cleaning with compressed air. Something might be stuck in the holder causing the drain.

If that doesn't work then I would just simply take the battery holder out when I am not using it. If that cures the battery drain problem then I would just leave it

 

On some busy days when I first got the 645N's a set of Duracell battery would last over 100 rolls inclduing powering the auto focus.

[kelly_hughes]

If it looks clean, nothing like dust or corrosion is going to eat the batteries faster. Bad contacts only break the connection making you think they are dead faster, but actually just not physically keeping the battery connected at all times.

 

I think you need to narrow down whether they are actually getting fully drained that quickly, or if they are coming out of the camera with quite a bit of juice still in them. The first scenario points to bad motor or something inside the camera, and the second scenario points to battery contact or broken wire/solder joint problem.

[xato]

Six AA cells will pack quite a bit electricity so if you can use them up within one roll, something is getting mighty hot if not warm. You could probably feel what part of the camera is getting warm. Or I would just try another set of batteries just on the chance you got a bad battery in the two sets you did you. The P645N and predecessor P645 are some the best cameras in the world that don't use up batteries quickly.

 

Warren

[kelly_hughes]

Also worth considering: You'll only get about one roll of film per set of batteries if you are using the

in-house brand AA batteries from Batteries.com. I thought I had a bad camera once because those batteries died

before a single roll was shot. I put in a second brand new set and the same thing happened. Luckily I had the

presence of mind to test a few more of the new batteries and immediately found that their lifespan was pathetic.

Not even 1/50 of what would be considered normal lifespan for AA batteries. I tossed all the Batteries.com

batteries that night and bought some Duracells. I'm about 10 rolls in, and still on the same set.

 

Come to think of it, I think it was one of my Pentax 645n cameras this happened on.

[aris_gerakis1]

I have narrowed down the problem to a faulty switch in the camera. I turn the camera off. Then, after a few weeks, the camera has

turned on by itself. So, the battteries are not the problem. How does the camera turn on, beats me. How much does it cost to fix that, I

cannot even start to imagine. It is an intermittent problem, one that would take a repair person weeks to sort out.

[Ian Taylor]

I doubt it would take weeks for someone even remotely competent.

My 645N went forever on a set of AAs.

[User_2000406]

<p>My 645NII always drained batteries even when turned off. I had to take it in to the shop to be fixed. The problem is now gone.</p>

[ben_karkabe]

<p>i just received a 645N and it looks like brandnew, yet same problem. very weird, it was a combination of things. Began wih the mirror getting stuck when I tested (dry-fyring/no film) all shutter speeds. I could not switch the camera off anymore, the digital display kept showing ISO, so I would take the battery holder out. Then it seemed I got around all that by skipping the 1 snd shutter speed setting. Then a couple of times the motor would start whining like a coffee grinder (I was still only testing shutter speeds), and then that would stop. I did set ISO from the original 50 to 100, started all over and again doing the coffee grinder thing. Then an 'E' sign so the batteries where drained. It seemed. Taking the holder out the batteries were very warm. Yet trying them afterwards in my contax RTSiii they still were usable/had juice.<br>

All the contact points seem very clean. The only thing that I ve noticed is the battery holder feels just a bit 'wobbly' after securing it in its place. There is a bit of play/no stiff assemblying with the camera body.<br>

The way things are now I think better return it to the eBay seller in Japan. Pity as the price was real good and the camera looks like mint.</p>