More on Z712 batteries

[Alan T]

I have now done more careful counts of my recent image files, and I can say the following of my two 'rechargeable CR-V3' batteries.

One is branded 'Digital' and one branded 'Uniross'. In the last two battery sessions, one lasting about 3 weeks and one a single week, I used each once. At the end of each run the camera shut down with no warning at all from the 'low battery' indicator.

I used the electronic viewfinder throughout, with very little reviewing of images on the large LCD screen. I did a lot of zooming. Focus & IS were on 'single', i,e., only operative whenshutter release button part-pressed.

From 4-22July, the 'Digital' battery took 87 images totalling only 52MB.
From 22-27July, the Uniross battery took 79 files totalling 142MB.

These results seem roughly consistent with my other results, less carefully recorded, from at least two other charges of each cell.

Camera and batteries are behaving reproducibly. Measurements on the two batteries, of open-circuit voltage and current delivered through two different standard resistors (37 ohm and 360 ohm),fully-charged and after camera shutdown are very consistent.

Current through the 360ohm resistor is about 9.5mA at start and 7.6-8.0mA at finish. The latter corresponds to 2.7-2.9V terminal voltage when passing this small current, so presumably the camera has a shutdown voltage above that.

This presumably leads to the disappointing performance, under fairly careful low-energy use, of these 'rechargeable CR-V3' Li-ion batteries, compared with the hundreds of shots obtained by others with the recommended KLIC-8000 Li-ion rechargeable and CR-V3 throwaway Li primary batteries. The different energy capacities do not account for the difference.

So for those users who, like me, have bought 'rechargeable CR-V3' batteries, I recommend that they either...

(a) carry a fully-charged spare, and preferably a backup disposable as well, as I am doing, or...

(b)consider getting (at considerable additional expense), a KLIC-8000 and charger, or adirect substitute, or...

(c) if desperate, experiment further with Ni-MH cells. I found wildly erratic behaviour ranging from just a few shots, to possibly as many as 90. I am unable to replicate the Ni-MH results. This is unsurprising, as the open circuit voltage of pairs of Ni-MH cells even fully charged will be close to the voltage at which my 'rechargeable CR-V3' batteries causeshutdown.

Unless my particular specimen of Z712 camera is faulty (and it's fine otherwise), for option (a) the spares are essential because there is little or no warning of shutdown.

I'd find any comparable results from other others of great interest. It's not necessary to say that throwaway disposables or KLIC-8000 work much better.I know that now.

[Alan T]

I've posted more about the Z712 with AA batteries in the 'Batteries & power supplies' forum at http://forums.steves-digicams.com/fo...=51&page=2

[mtclimber]

Allan-

I also use the Z-712 with both the Kodak Klic battery and Nickel Metal hydride AA batteries. We left for a 36 day cruise and I took over 400 photos using the two Klic batteries that I grabbed as we left the house.

Those two KLIC batteries powered the camera for 34 days. I had no recharger with me for the KLIC batteries, so I then used two AA size NimH batteries for the final two days with no problems at all.

I hope this is helpful.

Sarah Joyce

[Alan T]

mtclimber wrote:

I hope this is helpful.

Very much so! I wondered where you'd got to. I hope you've had a visually & photographically exciting, not too strenuous trip.

But I'm still not surewhether I have a faulty specimen of Z712 that shuts down prematurely. I've taken loads of shots, and I'm delighted with the camera in all other respects.

[mtclimber]

Alan-

It is not uncommon for a camera to shut down inadvertently when the battery power is low or minimal. Can you tell us a bit more about this shut down problem.

On our previous topic, if you can find a bargain price on non rechargeable CRV-3 batteries, they are good for 350 to 400 shots.

Sarah Joyce

[Alan T]

mtclimber wrote:

Can you tell us a bit more about this shut down problem.

On our previous topic, if you can find a bargain price on non rechargeable CRV-3 batteries, they are good for 350 to 400 shots.

Thanks very much for responding. I've posted rather a lot about it, so I'll send you a 'private message'. Hope you don't mind. On its way right now.

[Ronbaird]

Greetings Alan,

Please know that the CRV3 battery is a Lithium and is not rechargeable. You should be able to get between 400 and 600 shots depending on the camera and how it is used.

Also, you did not mentione them mAh rating for the batteries used. At present rechargeables are around 2500 mAh which will yield quite a bit more than a 1600 for example. Also, the number of charges made to the battery will have an impact. If they are relatively new, they should hold a full charge. If you let them sit and not use them for a while they will lose power over that time frame. I believe itis actually better to recharge them regularly than not.

Talk to you soon Alan,

Ron Baird
Eastman Kodak Company

[Alan T]

Thanks for the message, Ron.

The Ni-MH ones I've been using or trying to use as an experiment in the Z712is are 2000mAh. I've been doing measurements on them o/c and under two different loadsafter charging and after shutdown, and the same for 'rechargeable CR-V3' Li-ions (not KLIC-8000; I haven't got one, or a charger for it).

Unfortunately as the discussion has progressed the results are widely sprinkled in threads here and in the 'batteries & power supplies' forum. It's still not clear to me whether my particular Z712 is shutting down earlier than other specimens, and it's such a good camera I don't want to be deprived of it to find out for certain. It's fully usable as it is, provided I carry spare charged batteries.

Please are you able to tell us, or find out what, if any, the differences are between KLIC-8000 and 'rechargeable CR-V3' Li-ion batteries are, other than different Ah capacities and contact placement?

For example, there must be extra components in a 'rechargeable CR-V3' compared with a throwaway one, because a lower o/c voltage registers across the contacts the camera uses for them & disposable CR-V3 lithium primary batteries, than appears acrossthe pair of contacts used by the charger to charge these 'rechargeable CR-V3' from Uniross & other manufacturers. The camera is not exposed to the full EMF available from the cells themselves. Of course everyone else has just one camera and their own variety of assorted batteries.

Thanks for any help you can give. The Kodak website generally speaking makes it clear what is recommended and what isn't, but we have some folk claiming 200 shots on a pair of 2500mAh Ni-MH. I'm getting nowhere near that even on 'rechargeable CR-V3' (which you don't recommend either), and I reckon I'm a low current user (and I'm well-informed on the issues).

There's one place where I've posted a sequence of clicks on the European set of web pages that can givea misleading idea of battery recommendations. You ask for battery recommendations, and get to a page with a picture of Ni-MH cells as one option, but at the top it says 'choose your camera', and the Z712 isn't in the drop-down list. If I can find it I'll 'pm' it to you.

Thanks for any help you can offer, Alan T

[mtclimber]

Alan-

I still feel, very seriously, that the KLIC 8000 is the ideal battery for the Z-712 camera. Yes, there may indeed be alternative battery solutions, but is that really important. This is a camera, the photos are the most important issue/feature. Where are you going with this heavy duty battery discussionh?

Just wondering??

Sarah Joyce

[Alan T]

mtclimber wrote:

Where are you going with this heavy duty battery discussion?

Remember I and some others bought the camera expecting to use 2xAA Ni-MH like its predecessor models. Some still maintain this is possible, with hundreds of shots on a pair. I never believed that that many would be likely with only 2 cells.

I'm hoping to arrive at definitive conclusions on...

(a) whether my particular specimen is faulty and shutting down prematurely or not; whether the apparently poor 'low battery' indicator is working as intended;

and (b) whether or not my non-KLIC rechargeable CR-V3 Li-ions will work satisfactorily day after day 'in the field' without having to recharge every night in a very cramped camper van;

(c) whether I need to spend a lot more money than I'd expected, on top of what I've spent already:

Only occasional charging has been necessary with my previous digicams, in spite of lots of use when on vacation:

At Easter inthe Isle of Man Iforgot the charging cradle for my Casio EX-Z750. I took 300-400 shots (many panoramas) in 10 days. The battery indicator declined gracefully over the last couple of days.Near the end I bought a second battery, and had the shop charge it overnight for me in an EX-Z850, but I didn't actually need it. At present it looks from my own experience as though I'd need several recharges in that periodwith the Z712.

During all the discussion which has tired me as well as you, pertinent facts have appeared only gradually. It's slow and inconclusivebecause no-one has usedall 4 (or 5)possible battery systems (KLIC-8000, CR-V3 primary, 1 or 2 CR-V3secondary, Ni-MH). Ittakesanywhere betweena few & hundreds of shots to tell what's working, results are inconsistent, and the camera hasn't been around for long.

I've ignored Li primary AA cells. No-one has mentioned them as yet another option.

People who bought a KLIC-8000 and charger with the cameraall seem happy. Many haven't, because it's a rare & expensive proprietary battery system with a unique charger. Kodak don't supply it with the camera, as they have done before, in the UK at least.

It emerged only gradually that we have three different Li-ion systems that fit in the same hole, use 2 different pairs of contacts in the camera, and charge through three different pairs of contacts.

No-one reporting here as yet has thethird system which is on sale, a rechargeable "RCR-V3 high capacity" Li-ionthat is superficially identical to a disposable Li CR-V3. Its 2-contact charger could, potentially, be used in dangerous attempts to rechargea disposable primary Li CR-V3. I hope the primary cells have a diode to prevent this. Until recently it wasn't necessary, so I fear not.

Those of us like me who don't have the KLIC system and have paid already for alternativesare loth to invest unnecessarily in KLIC because its cost is a large fraction of that of the wonderfully cheap camera. I have already spent more on power for this camera than all its predecessors put together.

I forlornly hoped to have answers before going away, but I've failed. I still have the Casio to fall back on. This is a shame as the Z712 is an excellent machine.

Yesterday I thought of a new possible reason for rapid battery use. I'll raise that in another thread as it's quite distinct and Ron Baird may well dispose of it quickly.