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06-26-2007, 12:40 PM   #16
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QuoteOriginally posted by and Quote
Well I dont think its asking too much for a 5 point scale instead of a 2 point one :ugh:
Unfortunately, most consumers wouldn't accept it constantly swinging between points 2, 3 and 4 -- at least with NiMH.
I.e., it's not accurate at all.

Even Li-Ion is hard to gage.
You can tell when it's fully charged, but then you can't tell much difference between 90% full and 30% full either.

06-26-2007, 07:40 PM   #17
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QuoteOriginally posted by FireMate Quote
As to how much, Henry's has a policy that within the year, after you're past the "return for full value" point, you can get a full 50% of the value. I had bought the K110D back when it was a $700 unit, so I got half of that to put towards the now $899 K10D.

All prices Canadian.
I wonder how much Henry's will sell your old K110D for? I have a buddy who's looking around for one, and I've been scanning their site for a deal.
06-28-2007, 09:27 AM   #18
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I don't know what mine will go for, but for $500 you can get a K100 used from them: USED PENTAX K100D BODY 8+


And BJSMITH, thank you, that was a fantastic post and I really appreciated reading it! I've been very good over the years staying on top of battery technology as much as the average guy can, and while the basics are usually known, it was refreshing to read a knowledgable reply like that, that goes more in depth. Thank you!
06-28-2007, 11:10 AM   #19
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QuoteOriginally posted by FireMate Quote
And BJSMITH, thank you, that was a fantastic post and I really appreciated reading it! I've been very good over the years staying on top of battery technology as much as the average guy can, and while the basics are usually known, it was refreshing to read a knowledgable reply like that, that goes more in depth. Thank you!
The stupidest thing I see some people doing is trying to "balance out voltage" by putting in 2x NiMH plus 1x RCR-V3.

If you're lucky, the NiMH just melts because of the great difference in voltage -- i.e., NiMHs are constantly being "charged" by the RCR-V3. Nothing like melted NiMHs in a device -- which normally doesn't happen when the NiMHs are in normal use on their own (merely discharging).

If you're unlucky, the constant, and sometimes rapidly fluctuating potential-current causes a discharge -- possibly even a transient enough and similar to polarity being reversed. It happens all-the-time with Li-Ion cells when they are charging while being discharged at the same time, and you lose cells. Again, it happens. But when there are enough of them, you get what people have had issues with laptops right now -- BOOM!

Not my idea of a "good time" when I've got the unit up against my eye -- far worse than my legs with a laptop (or a table for that matter). Rare, and the NiMH batteries are far more likely to melt than this scenario occurring. But it's still a possibility.

So it's stupid to mix 2x NiMH and 1x RCR-V3 in an attempt to "balance out the voltage" so you don't over-volt the microelectronics. Your NiMHs will hate you overnight, and have a real chance of melting.

07-02-2007, 04:42 PM   #20
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nice one. we did almost the same but not with photography. my mum went up to inverness to enquire about contacts and myself and dad went shopping and low and behold we ended up at the car showrooms. ended up buying a brand new 206gti180 (one of the last to be registered). 2 weeks later back up to pick up the car and contacts with my grandpa and he bought a brand new jaguar xkr. dad says he will never go to a opticions again haha
07-03-2007, 12:05 PM   #21
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Regulated RCR-V3 batteries

There is a vast difference in the various options of rechargeable RCR-V3 batteries. Most are simply not safe in most (not all) digital cameras which use AA cells. The more expensive ones contain an integrated circuit, which among other functions, provides a low drop out voltage regulator (set at 3V). This allows the battery to supply 3V to the load until the actual battery voltage drops to about 3.05V. This is the only safe RCR-V3 to use. However, the cost of the RCR-V3 is significantly higher than 4 NiMH 2500 to 2900mAH batteries, so I would say that it is not an option to most.

Other options include the CR-V3 batteries which one can get over 2000 shots per set, and at under $9 USD a set (check for sales - that was the price at Wal-Greens a month ago, it would be hard to beat for an international trip or for backpacking.

Eneloops and Lithium Ion non-rechargeable AA cells work too, but for the average user, I would recommend 3 sets of NiMH AA cells (2500mAH or higher - should be under $10 a set of 4) and a Maha charger (several models out there). Keep a set of CR-V3s as a back up for those times when you don't get a chance to recharge the AA's.

Like other have said, never mix battery types. It can lead to premature end of life for rechargeables and can result in faster discharge for Alkalines.

Wayne (who spent over 20 years in the power conversion controller/power supply industry as a Technology Manager/Design Engineering Manager).
07-03-2007, 03:50 PM   #22
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QuoteOriginally posted by wayne Quote
There is a vast difference in the various options of rechargeable RCR-V3 batteries. Most are simply not safe in most (not all) digital cameras which use AA cells. The more expensive ones contain an integrated circuit, which among other functions, provides a low drop out voltage regulator (set at 3V). This allows the battery to supply 3V to the load until the actual battery voltage drops to about 3.05V. This is the only safe RCR-V3 to use.
This what is so confusing to us battery noobs. We have people that seem to know what they are talking about stating the opposite, one says it's safe the other says it's not. Would be nice if this issue was settled once and for all.
07-04-2007, 09:25 AM   #23
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Finally, an expert!

QuoteOriginally posted by wayne Quote
There is a vast difference in the various options of rechargeable RCR-V3 batteries.
And hence why most vendors ship a proprietary 7.2V, 10.8V or 14.4V Li-Ion/Li-Poly battery pack, instead of requiring 2, 3 or 4 RCR-V3s.
It's bad enough that the variance is great with just one (1) RCR-V3, but even more so with multiple.
It's easier to regulate the entire series circuit of Li-Ion/Li-Poly cells in one unit.

QuoteOriginally posted by wayne Quote
Most are simply not safe in most (not all) digital cameras which use AA cells. The more expensive ones contain an integrated circuit, which among other functions, provides a low drop out voltage regulator (set at 3V). This allows the battery to supply 3V to the load until the actual battery voltage drops to about 3.05V. This is the only safe RCR-V3 to use.
And by "safe to use" I assume you mean "safe to use in general."

Most people here don't realize that Li-Ion/Li-Poly cells die below 3.0V, typically by 2.7-2.8V in the best case.
That's why regulation is included, although that regulation itself also uses power (and why storing at about 3.3V, about 40% charge left, is ideal).

On the other flip, people also don't realize that the regulator and microelectronics in the K100D were built for a 4.8-6.0V nominal, operating voltage -- 4x AA.
As such, is materially impossible for two (2) RCR-V3 cells to provide that, as they will provide -- even the best regulated ones -- 6.0-7.2V for 2x RCR-V3.

Lastly, on another board, someone started talking about "no load" v. "nominal operating/load" voltages.
AAs such as Alkaline, NiMH and Lithium can read over 1.5V on "no load," up to 1.8V -- and RCR-V3 proponents say, "oh, 2x 1.8V = 3.6V, so RCR-V3 is safe if non-rechargeable is safe."

What they don't say is that RCR-V3 and other Li-Ion/Li-Poly cells can read 3.6-4.2V with no load!
Li-Ion/Li-Poly charges at 4V+, typically around 4.2V, and many charged RCR-V3s, even regulated, will show 4V+ on a volt-meter when no load is applied

The RCR-V3 proponents don't compare "load" v. "load", "non-load" v. "non-load", but what they want to fit their argument.

QuoteOriginally posted by wayne Quote
Eneloops and Lithium Ion non-rechargeable AA cells work too, but for the average user, I would recommend 3 sets of NiMH AA cells (2500mAH or higher - should be under $10 a set of 4) and a Maha charger (several models out there).
That's exactly what I do, although I have a cheaper LaCrosse 900 series discharger/charger.
I always discharge/charge at 250/500mA or higher, as I've read about the failure of the LaCrosse to detect the DeltaV issues when charging at 100/200mA, and will over-charge the batteries.

QuoteOriginally posted by wayne Quote
Keep a set of CR-V3s as a back up for those times when you don't get a chance to recharge the AA's.
Exactomundo, or at least 4x Lithium AAs in place of 2x CR-V3s.
The advantage of the former is that they are available in almost every store that cells batteries.

QuoteOriginally posted by wayne Quote
Like other have said, never mix battery types. It can lead to premature end of life for rechargeables and can result in faster discharge for Alkalines.
What do you think of the "voltage balancing" of 2x AA NiMH and RCR-V3?
I think it's pretty stupid and a good way to melt your NiMH batteries, possibly (even if only 1 in 100,000) cause a quick transient and polarity reversal (and we both know what polarity reversals do to Li-Ion/Li-Poly .

QuoteOriginally posted by wayne Quote
Wayne (who spent over 20 years in the power conversion controller/power supply industry as a Technology Manager/Design Engineering Manager).
Finally, an expert!
I'm an EE, but I've spent all my years in Microelectronics, and not even any regulation logic designed for them.

On countless boards I've seen the RCR-V3 proponents flaunt how quick their AF motors are with RCR-V3.
Of course! Such 5-6V motors, TTL logic and other circuits love to be over-volted and can typically take up to 9V.

But the voltage regulator that Pentax put in the K100D doesn't like that, nor the microelectronics behind it.
I don't know how many times I have to point this out -- if you have a CMOS designed for 1.5V and you through 1.8V at it, you're lucky if it lasts long!

Even a PC tech who has over-volted DRAM or CPUs would realize this!

QuoteOriginally posted by CSpronken Quote
This what is so confusing to us battery noobs. We have people that seem to know what they are talking about stating the opposite, one says it's safe the other says it's not. Would be nice if this issue was settled once and for all.
Things to know ...

1) There is a difference between motors, TTL circuits and lower power CMOS and microelectronics. Over-volting the former is tolerable in many cases (and you'll get faster AF), but not the latter, or at least it seriously degrades device lifespan (like your K100D's microcontroller and CCD).

2) Lithium AA cells are not the same materials as Li-Ion/Li-Poly cells. The former are designed for nominal operating of 1.2-1.5V (non-load/charge of even 1.5-1.8V). The latter are designed for nominal operating of 3.0-3.6V (non-load/charge of 3.6-4.2V). Doing the math of you will see the peg don't fit -- you can't fit X in Y perfectly.

3) Pentax did not include the voltage regulation required to "tame" varying Li-Ion/Li-Poly in the K100D, unlike the K10D, likely for cost considerations. And even the K10D comes with its own, proprietary battery back, not tempting the variance with multiple RCR-V3s.

4) Don't taunt Li-Ion/Li-Poly by mixing it with AA NiMH batteries in an attempt to "balance out voltage" to protect the K100D's voltage regulation and microelectronics. "Don't taunt happy fun battery" (i.e., Li-Ion/Li-Poly

07-04-2007, 10:32 PM   #24
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Okay, I just blogged it ...

I'm looking for power EEs to critique and correct ...
BS' Blog: Li-Ion is not Lithium (e.g., Li-Mn, Li-Fe)
07-06-2007, 02:17 PM   #25
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in January I thought about getting a cheap DSLR.. almost went with Rebel XT, then D40 was on the flyer of a local store.. long story short, I walked out with the K110D, the very next day I went back and exhange it with the K100D with 2 kit lens

In May, I bought a K10D since everyone was talking about it have been happy ever since, though I drool over my friends' D80 and 30D quite and fast focus
07-08-2007, 07:40 PM   #26
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Internal regulation in cameras

Bryan,

Although I have not discussed the internals with the engineers at Pentax, I have with engineers from Canon and Sony. They have internal power conversion circuits (multiple) to handle the various requirements. For the most part, they use either buck (step down) converters or boost (step up) converters rather than linear regulators. For example, the CPU for most digital cameras runs on less than 3V while the motors are typically run off the battery power. Backlighting also requires a different voltage (the original designs used a CCFL tube, much like those used in laptops and LCD monitors) while newer designs may use white LEDs. Another interesting point, the back light color differs from market to market (cooler or warmer, depending upon the region preference - there really is a difference between the Japan model vs say a US model).

Getting back to the regulation issue, they also design in local regulators. These are typically low drop out designs which provide noise free power to sensitive circuits. They also allow you to turn off functions (such as anti shake) to conserve power. Some of these may be incorporated into the custom IC's used in the camera, or they can be individual circuits (which can be as small as a SOT-23 package (very tiny).

Depending upon the design of the power circuitry, the engineers may have been counting on a certain range of input voltage to maintain regulation. Getting back to the buck/boost converters, unless you design in a complex design which combines both functions (more parts, larger board or flex area), your basic step down converter wants the input to be higher than the output while the boost converter wants the input to be lower than the output (there are other methods, but that is not for this discussion).

So, the input to the camera should be between a range of voltages determined by the designers. If you fall outside of that range, you could have a problem. If the manufacturers says that an RCR-V3 battery may damage the camera, then I for one would not use them (my camera is worth more than a desire to have rechargable RCR-V3's). Oh, again, as many have stated, don't ever mix battery types. It is more than the voltage that you need to consider (internal resistance of the cells, discharge rates, thermal ratings, etc).

Wayne
07-09-2007, 08:48 AM   #27
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Thank you for this!

QuoteOriginally posted by wayne Quote
Bryan,
Although I have not discussed the internals with the engineers at Pentax, I have with engineers from Canon and Sony. They have internal power conversion circuits (multiple) to handle the various requirements. For the most part, they use either buck (step down) converters or boost (step up) converters rather than linear regulators. For example, the CPU for most digital cameras runs on less than 3V while the motors are typically run off the battery power.
Yes, I know this, as does the K100D, the K10D, etc...
I'd never design a product to run microelectronics directly off of a power source these days, not even 5V tolerant 3.3V ICs.
Thank you for stating how this is "common knowledge" among anyone who has designed anything with ICs.
Some people on various boards have even accused me of making this up, or how my experience is a non-consideration since I don't know anything about the K100D.

QuoteOriginally posted by wayne Quote
Getting back to the regulation issue, they also design in local regulators. These are typically low drop out designs which provide noise free power to sensitive circuits.
Which has also been of great discussion with regard to the K100D.
Some people claim the K100D is supposed to drop out at 4.5-4.7V, which sounds nominal for a 4xAA NiMH device.
Others claim it's dropping out on them at 5V+, which would make sense if NiMHs are fully charged and delivering around 1.25-1.3V and don't last long.
5V+ would definitely be too high for regular 4xAA NiMH use, and people should take such issues up with Pentax -- especially if it's happening with Sanyo Eneloop and Energizer NiMH 2500.

QuoteOriginally posted by wayne Quote
So, the input to the camera should be between a range of voltages determined by the designers.
If you fall outside of that range, you could have a problem.
Which I've been repeating like a broken record on this board, among others.

QuoteOriginally posted by wayne Quote
If the manufacturers says that an RCR-V3 battery may damage the camera, then I for one would not use them (my camera is worth more than a desire to have rechargable RCR-V3's).
Yes! Yes! Yes!

QuoteOriginally posted by wayne Quote
Oh, again, as many have stated, don't ever mix battery types. It is more than the voltage that you need to consider (internal resistance of the cells, discharge rates, thermal ratings, etc).
Yes! Yes! Yes!

I tire of people saying, "oh, I'll just do that to 'average out the voltage,'" and get pissed at me when I say that's "being stupid" in my blog entry.
I know that's a harsh way to put it, but it's pretty universally known -- even to non-techs -- that you don't mix battery chemistries.
Too many people ass-u-me it's because of the chemicals themselves mixing, when that has nothing to do with it.

Thank you again for this information/confirmation!
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