[retroflex]

Does anyone know if the K-x can use CR-V3 batteries?

I currently have a DS and use rechargeable CR-V3's... would be great if I can continue using them if I upgrade.

[Iskandar Taib]

Careful. There is the CR-V3 primary (i.e. non-rechargable) lithium battery, which is nothing more than two AA lithiums in one supposedly-more-convenient case (and which costs quite a bit more than two AAs..). This one has a voltage of 3.0V and is approved for use with Pentax dSLRs. In fact, I've heard the cameras were designed for them.

Then there's the RCR-V3, which is a lithium ion cell packaged like a CR-V3. These put out 3.7 volts. Pentax recommends these NOT be used (though you hear of people using them with no problems). Some are said to have a "voltage regulator" in the packaging, but I really wonder about that. Linear voltage regulators get hot, because they're soaking up the difference in voltage and converting it to heat.

Iskandar

[rawr]

Does anyone know if the K-x can use CR-V3 batteries?

The K-x manual doesn't say anything about rechargable CR-V3's, but I'd say probably yes, if the output is electrically compatible.

Physically, the profile of the battery compartment is not too snug but there is a slight ridge between each AA pair. So I guess the issue will also depend on the profile of your batteries.

Worth noting: I think the dimensions at least of the battery compartment in the Km/K2000 are identical to the K-x. If they worked on/ fitted into the Km/K2000, they should work on the K-x. It might be worth searching around to see if any Km/K2000 users have reported success using RCR-V3's.

Do RCR-V3's work any better than for example NimH's like the 2000mAh eneloops?

[HogRider]

I asked the same question at the DPreview forum and was told no. Here is a link that explains why:

RiceHigh's Pentax Blog: K-m Battery Issue, Solution and Timing Measurbations

It's too bad because I always love that battery pack. I went on a 2 week trip with my *ist DL in 2006. Put in new Energizer CR-V3 and brought 1 spare pack. I shot almost 1600 photos and never had to change the battery. That was great.
Never had a problem in any camera using them!

[retroflex]

Careful. There is the CR-V3 primary (i.e. non-rechargable) lithium battery, which is nothing more than two AA lithiums in one supposedly-more-convenient case (and which costs quite a bit more than two AAs..). This one has a voltage of 3.0V and is approved for use with Pentax dSLRs. In fact, I've heard the cameras were designed for them.

Then there's the RCR-V3, which is a lithium ion cell packaged like a CR-V3. These put out 3.7 volts. Pentax recommends these NOT be used (though you hear of people using them with no problems). Some are said to have a "voltage regulator" in the packaging, but I really wonder about that. Linear voltage regulators get hot, because they're soaking up the difference in voltage and converting it to heat.

Iskandar

Thanks for the warning. I use Vanson RCR-V3's which I believe should have a built-in regulator. Before I bought them I checked that others had success with exactly these batteries and eventually I dared to try them myself... good thing cause now I've used them for years with no problems.

Before that I used regular CR-V3's which, though working great, got too expensive in the long run. At the time Eneloops and similar batteries did not exist afaik.

But this is for the DS of course, other models might be more sensitive to the voltage or heat...

[retroflex]

Do RCR-V3's work any better than for example NimH's like the 2000mAh eneloops?

Thanks for the help rawr. I have not tried Eneloops or similar so I can't comment on that. But RCR-V3's definately makes the AF snappier than regular alkalines.

[retroflex]

I asked the same question at the DPreview forum and was told no. Here is a link that explains why:

RiceHigh's Pentax Blog: K-m Battery Issue, Solution and Timing Measurbations

It's too bad because I always love that battery pack. I went on a 2 week trip with my *ist DL in 2006. Put in new Energizer CR-V3 and brought 1 spare pack. I shot almost 1600 photos and never had to change the battery. That was great.
Never had a problem in any camera using them!

Thanks for the help HogRider! So RH can actually provide some useful info

Yeah, the non-rechargeable CR-V3's lasts forever. Last time I used them was also on a trip. Brought 2 sets of batteries and switched to the second set after 3 weeks. But I didn't shoot as many shots back then as I guess I do now... still very good batteris.