Lithium Batteries for Pentax 67-ii

[mtjade2007]

Just wondering what Lithium batteries every P67-ii owner uses. I used to use just standard CR123s for a few years but found them not last very long and had to replace them more than once a year despite that I don't really use the camera that much. So I switched to use rechargeable CR123s. I am using a pair of Lifepo4 CR123s. So far they have served me extremely well. They last more than a year from one recharge. I no longer worry if my batteries will run out of charge in the middle of a photography road trip.

However, I am concerned about the voltages of these rechargeable CR123s. There are basically two types of rechargeable CR123s, one of the Lithium Ion type and the other Lifepo4 type. The first type has a nominal working voltage around 3.7 volt. That is obvious a bit too high for the p67-ii camera. The standard non- rechargeable CR123s have a nominal working voltage around 2.8 volt only. The Lifepo4 type CR123 has a nominal working voltage of 3.2 volt, which is still very high than regular CR123s. I really like the Lifepo4 CR123s. Their working voltage remain at 3.2 volt then drop to 3.0 when they are about to run out of charge. The non rechargeable CR123s have a 2.8 volt and drop to 2.5. The camera seems do not like them to drop off to 2.5 volt and will reject them before that.

I recently discovered that the Lifepo4 one fully recharged has a voltage as high as 4.2 volt but will stabilize to 3.7 a few hours later. I put them on my P67-ii and shot a roll of film and still fund them at 3.35 volt. This has me worried. I know I have not had any problems after many years of using them. But the higher voltage may be a problem down the road if I keep using them. I think the Li Ion type CR123s at 3.7 nominal working voltage is definitely too high and should not be used on P67-ii. I am just wondering if the Lifepo4 type at 3.2 volt is till too high. Anyone any thoughts?

 

[johnha]

Given that failure of the electronics is one if the biggest problems with the 67ii and that there are no spare parts, I wouldn't use anything other that the correct specified batteries if I was lucky enough to own one. Skimping a few dollars on a $2000 camera doesn't make any sense.

 

[AgX]

The standard non- rechargeable CR123s have a nominal working voltage around 2.8 volt only.

Primary CR123 cell:
nominal voltage is 3V.
open source voltage is even a bit higher at 3.2V
load voltage is 3V
Even for a load making the cell only last 1/3 year the voltage still is above 2.8V

Data taken from manufacturer's data handbook (Varta)

 

[John Koehrer]

No problem after many years?
Usually the magic smoke shows up very quickly when things go awry. Think in terms of "POOF"

 

[itsdoable]

CR123 batteries may be 3.2V new, but they settle to ~2.8 very quickly for most of their load life.

 

[mtjade2007]

Been away for a while. Sorry for not follow up quickly.

I have used a pair of LiFePO4 CR123 for probably more than 5 years. So far there is not any problem. But I only used the camera a couple of times per year. Wnenever I took the batteries out and checked the voltage they were always between 3.0 and 3.2 volt. I believe at these voltage level they are safe to use. The problem is really when they are fully recharged and full of juice. They will be at 3.6 or even 3,7 volt. This had me rethink about safety. I guess I could put them through a flash light or something to discharge some juice until their voltage drops below 3.3 then use them in the camera.

What is really important about rechargeable CR123s is there are at least two types of them. One is the LiFePO4 type which is what I use. The other more common one is the regular Lithium Ion type. This type of CR123 shoud not be used in P67-ii. The LiFePO4 has a nominal voltage of 3.2 volt. The Lithium Ion type on the other hand is at 3.7 volt, which is definitely too high for the P67-ii.

By the way, Panasonic batteries are said to be among the worst. If its voltage drops to below 2.8 volt it could be rejected by the P67-ii any time. I know Pentax said a pair of CR123 could last tens of rolls of films but with Panasonic CR123 they did not last more than a dozen or so of 220 rolls for me. They stopped working for me in the middle of my photo shoot road trips for quite a few times which was the reason I switched to use the pair of LiFePo4 CR123s.

 

[braxus]

Anyone ever had an issue of the P67II draining batteries to nothing from just sitting for a couple months? I put fresh batteries in my camera and didn't use it for a couple months. When I went to use the camera, the batteries were dead. Is this common for this camera. I take my batteries out now till I go to use the camera.