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Pentax warning on rechargeable CRV3's

George Lazarette
Posted 29/08/2006 - 20:17 Link
I think the most important thing with batteries is to be able to charge each one individually. I am currently using a very cheap machine from 7dayshop which does just that, with the option to run a discharge cycle first.

My oldest NIMHs are now two and a half years old and still going strong. And they get lots of use.

Keywords: Charming, polite, and generally agreeable.
old timer
Posted 30/08/2006 - 16:53 Link
One of the great things about the Penatx digital series is that they use AA cells - probably the most common and cheapest of all batteries.
What is the betting that the next Pentax uses a proprietry battery at phenominal cost?
Keep up the good work

I'll think of something someday.
Posted 30/08/2006 - 20:49 Link
Graham, I don't think Pentax would do something like that - it's not really their style, I mean if they still produce cnew bodies that work with 50 y-o lenses I don't think they'll p*ss us off over batteries.

I have just got hold of an Ansmann 8, and it's everything Matt said it was - and as big as he said it was too!
Tim the Ammonyte
K10D & sundry toys
Posted 30/08/2006 - 22:00 Link
I hope you're right Tim, but if Pentax follow the lead of other technology manufacturers, they just might do exactly that.

Take Inkjet & Laser printers for instance. They used to cost an arm and a leg which made the consumables look cheap enough. Things have changed dramatically however. They are almost giving the things away with a packet of cornflakes, but the consumables have, if anything, increased in price.

Once Pentax have sold a camera, that's it, no more income from that camera unless it goes wrong outside warranty or needs servicing. But it will need a new battery every couple or three years, and they'll never give you 2 sets of batteries, so we'll all need to buy a spare, right.

Perhaps that's just me being cynical, but it could happen. After all, they have a somewhat captive audience with all those Pentax users that have more than one or two lenses. A new camera model that requires a custom battery might annoy some, but eventually they'll buy just to keep up with the latest technology.
Peter E Smith - flickr Photostream
Posted 30/08/2006 - 22:44 Link
the inkjet thing sucks.
used to buy the all in one color cartridge for epson, but individual tanks were purportedly cheaper and therefore in response to demand, epson I find it cheaper to buy a "carton" pack of all six colors than to but them seperately and dark blue cartridges piling up unused.

I saw a canon ip 1500 at Walmart for $59.00 that included ink and the cost of the ink cartridges on the shelf next to it cost $72.00!

What would be nice is a simple solar powered recharger for the AA's
Fired many shots. Didn't kill anything.
Posted 31/08/2006 - 00:00 Link
I've used an Exide solar charger for my NiMh batteries for a couple of years. Works great, and only cost about 15 on ebay. Its designed for NiCd's but the output voltage is sufficient to trickle charge NiMh's as well.

Have a look at this one, its the same as the one I use.
Peter E Smith - flickr Photostream
George Lazarette
Posted 31/08/2006 - 08:53 Link
Looks good.

The blurb says: "giving you the freedom to use anywhere in any situation".


Keywords: Charming, polite, and generally agreeable.
Posted 31/08/2006 - 11:13 Link
The arctic circle in June?
Tim the Ammonyte
K10D & sundry toys
Posted 31/08/2006 - 11:28 Link

The bit I picked up in the the blurb was "12 hours of sunshine" . . . in UK?

Works great in Spain though.
Peter E Smith - flickr Photostream
Posted 31/08/2006 - 11:30 Link
It should work at night too . . . just wire up a torch to the batteries your charging, then shine the torch on the solar panel.
Peter E Smith - flickr Photostream
Posted 02/09/2006 - 19:56 Link
impotentspider wrote:
I cant see the point of CRV3's can anyone tell me why this battery was developed? ie; whats its advantage over AA's, its certainly not price! ....

The CRV3 has a larger capacity over the traditional AA. However, with supply/demand the rechargeable AA has now have a capacity that makes it uneconomical to buy rechargeable CRV3. Also I believe that the voltage output on a rechargeable is 3.2v. So 3.2x2=6.4v is too much for a Pentax battery input. I wonder what will happen if you make up a power pack with two rechargeable CRV3s and plug it in the mains adaptor point on a pentax which has a input rating of 6.5v, I mean apart from having wires all over and flap doors opens ready for breaking off.
Posted 04/09/2006 - 09:28 Link
(Back from hols )

There are two types of rechargeable CR-V3s. There's the original that are to be avoided - they have an output of 3.6V, and this is too much indeed.
Then there's the Uniross "compatible" CR-V3s which have three terminals and output at 3V and claim "100% compatibility".

As to why you use them - they have a much lower self discharge rate (so fully charged cells remain that way longer when not being used), and I also found that they seem to run cooler when doing very long exposures. I did some simple astro-photog on hols with 30s to 80s exposures and the batteries were only just warm. The last time I tried with NiMHs they got really warm. The warmer they get the more noise you get

Oh yes, and they are fractionally lighter in weight!

Posted 04/09/2006 - 18:19 Link
I do worry about those Uniross CRV3s. I have two pairs which I have been running on my DS but I have found that newly charged they seem to have an on-load voltage of around 3.4 volts so I worry that a pair at 6.8V is a bit risky.

[Measuring on the 3rd terminal, which I assume is before the diode, gives an on load voltage of around 4.2v on recently charged samples. If this represents the non-dioded rechargeable CRV3s then I think these would be fatal to a Pentax DSLR.]

With the Uniross it seems that in use the voltage quickly drops to 3v and seems to stay there but I'm concerned that the initial voltage is going to cause some damage.

I've therefore gone back to using Ni-Mh, with a decent charger, for general use and non-rechargeable CRV3s for important events.

Daniel Bridge
Posted 11/09/2006 - 23:15 Link
Having fully discharged and recharged my 4 NiMH's (see previous post), they seem back to normal - whereas they were showing 'half' power after 70 images or so, I took around 400 on saturday and they still showed 'full'. Maybe not the most scientific way of doing things, but it worked for me.

Saso E.
Posted 14/09/2006 - 14:14 Link
I bought a two packet of GP 2300mAh rechargeable batteries and the charger and it's work like a charm in my *isd D.

Bye - S.

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