PentaxForums.com - View Single Post - K200D not compatible with 540FGZ P-TTL?

bjsmith · 08-03-2008, 03:57 PM

Originally Posted by Ash

Wow Bryan,
Great explanation.
I suppose then the technology is not available for rechargeable batteries to run at 1.5V with their rated mAh until near dead.

Impossible. Unlike other materials, which are little more than the chemical, Lithium designs have internal, regulatory microelectronic circuits. They just "die" when the charge drops enough. That's why Lithium battery technology is so well trusted, because it's either providing virtually all of the rated current, or it doesn't work at all.

In the case of Lithium-Ion (rechargeable Lithium) technology, the Lithium-Ion cells typically die at 2.9-3.0V. So the cut-off is typically several tenths of a volt higher. Why? Because the microelectronic regulatory circuits themselves pull current, so to protect the longevity of the cells, they "cut-off" well before dropping near 3.0V. Li-Ion batteries should be charged yearly, if not every six (6) months. It's best not to "deep cycle" (discharge-charge) Li-Ion, and keep them at least 30% full (if not 50%+).

LiMg is the non-rechargeable compound in CR-V3 batteries. It is 3.0V nominal. LiFe is the non-rechargeable compound in Energizer's proprietary e2 Photo Lithium. It is 1.5V nominal. There is no 3.0V nominal Li-Ion, they are all 3.6-3.7V+. There is no rechargeable regulation circuits to maximize cell longevity in LiMg/LiFe, because they are 1-time use. There are only overload and other circuits, to prevent against combustion in the case of polarity reversal. They don't use power, and have a very long shelf-life (10+ years) as a result.

Many Rechargeable CR-V3 (RCR-V3) claim 3.0V, but it is impossible for them to provide such natively. I have no idea what kind of loads and/or transforms they are using, but they will vary and be non-standard. Use at your own risk. A few of the allegedly "tolerable" RCR-V3s that always stay below 3.3V (so they should be 6.5V or less in pairs) use a third terminal for charging, because charging of Li-Ion is 4.2-4.3V (long story). That greatly reduces the risk of having a transient greater than nominal, unlike those that charge over the same terminals they provide output on.

In any case, while NiMH has higher current-time ratings of 2000-2000mAh, and Lithium battery technologies are typically only 1500mAh or so, the latter is "better" for high real-time current applications of 1A (1000mA) plus, whereas the latter is adversely affected as charge drops. I.e., the actual "charge" you get out of NiMH depends on if you're sucking up 100mA or 1A (1000mA) plus. If you're only sucking 100mA, you'll get that full 2000-2500mA (20+ hours). Even 500mA might come close (3-4 hours). But if you're sucking 1A+, forget it, you're not going to get the equivalent (maybe not even 1 hour). Energizer's NiMH charts show how actual duration exponentially decreases with real-time load, not linearly.

Lithium battery technologies, on the other hand, either provide the current they are rated at, at the voltage they are rated at, or their regulatory logic prevents it. Energizer e2 Photo Lithium provides up to 2.6A at 1.5V. You'll get close to the same duration whether you're pulling 100mA or 2A. If you try to put more than 2.6A, unlike a NiMH chemical battery which will "work, but drop voltage," it most likely will not at all, as the regulatory logic kicks in (possibly even killing its cells). This is so the battery does not combust.

Alkaline, NiCD, NiMH and other battery technologies melt. They do not support combustion in our N-O environment. Lithium combusts. It doesn't quite "explode," but the effects can look like it.

Originally Posted by Ash

I've been caught recently having two sets of fully charged NiMH AAs (which are about a year old but have definitely been charged for less than 1000 times) and only been able to draw a total of 10 flashes between them at 1/2 power.

NiCD was used for higher-current applications in the past, but they have serious memory effect and other issues. NiMH became far more commonplace because most applications -- such as AA -- are only 100-500mA loads. NiMH also has much longer charges in current-time than NiCD. Now that we're doing 1A+ in cameras, NiMH doesn't cut it as well. Virtually any brand other than Energizer or Sanyo Enelope is "half battery" (or worse) when I put them in, because they are not providing adequate current, and voltage is dropping.

Energizer and Sanyo use over-charged designs to provide more real-time current. Energizer rates theirs as 2500mAh and I've measured them to provide over 1.5A at as high as 1.3V (1.2V is nominal), as does Energizer's own charges (see their site). Unfortunately the over-charge seems to "wear off" in a month, and the current-time drops to 1700mA and I'm getting 1A or less. Sanyo uses a more sustainable approach in their 2000mAh current-time designs, which drops less over time, but still provides 1.5A+

Unfortunately, NiMH is only 1.2V, so in a set of four (4), that's only 4.8V -- maybe 5.2V if you're getting 1.3V/unit at full charge (as both the Energizer NiMH charts show, and I have personally experienced). Your auto-focus motors and flash output is going to be far less at sub-5V versus the full 6V you'd get with 2x LiMg (CR-V3) or 4x LiFe (e2 Photo Lithium). There have even been reports of "cut out" when people use NiMH because the K100D/K200D voltage regulator doesn't like anything less than 5V. Normally a K100D/K200D should operate with 4.5-6.5V. Such cameras that can't work with 4.8V using Energizer/Sanyo NiMH fully charged should be returned to Pentax.

BTW, I always drain'n charge my NiMH batteries, to measure the exact current-time. There is no way to measure "charge" otherwise, and the voltage output is only an "indicator," not exacting. And even then I still get a "mis-charge" in one (1) out of ten (10) NiMH batteries. All it takes is just one NiMH battery in the series circuit to be providing inadequate current for the entire set to drop voltage. All batteries in a series circuit must provide the adequate current/voltage or they all suffer.

Regardless of what you use, just make sure the circuit never outputs more than 6.5V or you can damage the microelectronics. I have seen many, many posts on many forums were people gleefully talk about "how good" their AF motors are, but they have an occasional "issue" with the shutter, menu, etc... which means the microelectronics are being over-volted and the regulator can't deal with it. Pentax's regulator is only designed for 6.5V, and (seemingly, I haven't verified this though), a 4.5V cut-off. The latter won't damage the camera, it just won't power up. The former can easily damage the regulator and cause the unit to fail, and often will in order to protect the microelectronics.

I.e., when I've designs boards, I design the regulator to fry before the microelectronics behind it -- especially if the regulator is on a different PCB or can otherwise be replaced easier than the "brains" behind it. I find paying $19 for twelve (12) Energizer e2 Photo Lithium batteries at Costco and Sam's Club is the "best buy" -- in my time, money and piece'of mind. That's for myself and my K100D. I honestly got tired of the "housekeeping" with NiMH, and carrying 3-5 sets. I found the AF.C mode at sporting/action events really drained them (AF.S was otherwise fine though).

As I mentioned, I've designed microelectronic circuits myself. While I don't consider myself a "power" type of EE, I don't really care to risk my K100D to RCR-V3s which have an inherit compound that is almost a full volt over the maximum rated voltage on the K100D's regulator. Others may have a different opinion and swear by the aftermarket options they've chosen. Again, there is a reason why all Li-Ion batteries designed for all microelectronics are proprietary, and never use generic RCR-V3 (unlike non-rechargeable CR-V3s, which are LiMg, not Li-Ion).

Then again, I'm the type that pays almost $40/each for the Pentax branded 7.2V/1600mAh Di50 batteries and the Pentax branded BK50 charger for the K10D/K20D. When it comes to Li-Ion, and the great variations, I just don't trust aftermarket. Statistics do show that even cheap Li-Ion batteries will, to an almost certainty, kill their own cells before combusting. But it's the little operational variations that I don't want damaging my K20D microelectronics over time, and I don't like to leave something to the smallest chance. But I used to work in aerospace, so I could be "overly anal."

08-03-2008, 03:57 PM	#17
bjsmith Senior Member Join Date: May 2007 Location: Orlando, Florida (USA) Gallery Photos: 0 Posts: 238	Originally Posted by Ash Wow Bryan, Great explanation. I suppose then the technology is not available for rechargeable batteries to run at 1.5V with their rated mAh until near dead. Impossible. Unlike other materials, which are little more than the chemical, Lithium designs have internal, regulatory microelectronic circuits. They just "die" when the charge drops enough. That's why Lithium battery technology is so well trusted, because it's either providing virtually all of the rated current, or it doesn't work at all. In the case of Lithium-Ion (rechargeable Lithium) technology, the Lithium-Ion cells typically die at 2.9-3.0V. So the cut-off is typically several tenths of a volt higher. Why? Because the microelectronic regulatory circuits themselves pull current, so to protect the longevity of the cells, they "cut-off" well before dropping near 3.0V. Li-Ion batteries should be charged yearly, if not every six (6) months. It's best not to "deep cycle" (discharge-charge) Li-Ion, and keep them at least 30% full (if not 50%+). LiMg is the non-rechargeable compound in CR-V3 batteries. It is 3.0V nominal. LiFe is the non-rechargeable compound in Energizer's proprietary e2 Photo Lithium. It is 1.5V nominal. There is no 3.0V nominal Li-Ion, they are all 3.6-3.7V+. There is no rechargeable regulation circuits to maximize cell longevity in LiMg/LiFe, because they are 1-time use. There are only overload and other circuits, to prevent against combustion in the case of polarity reversal. They don't use power, and have a very long shelf-life (10+ years) as a result. Many Rechargeable CR-V3 (RCR-V3) claim 3.0V, but it is impossible for them to provide such natively. I have no idea what kind of loads and/or transforms they are using, but they will vary and be non-standard. Use at your own risk. A few of the allegedly "tolerable" RCR-V3s that always stay below 3.3V (so they should be 6.5V or less in pairs) use a third terminal for charging, because charging of Li-Ion is 4.2-4.3V (long story). That greatly reduces the risk of having a transient greater than nominal, unlike those that charge over the same terminals they provide output on. In any case, while NiMH has higher current-time ratings of 2000-2000mAh, and Lithium battery technologies are typically only 1500mAh or so, the latter is "better" for high real-time current applications of 1A (1000mA) plus, whereas the latter is adversely affected as charge drops. I.e., the actual "charge" you get out of NiMH depends on if you're sucking up 100mA or 1A (1000mA) plus. If you're only sucking 100mA, you'll get that full 2000-2500mA (20+ hours). Even 500mA might come close (3-4 hours). But if you're sucking 1A+, forget it, you're not going to get the equivalent (maybe not even 1 hour). Energizer's NiMH charts show how actual duration exponentially decreases with real-time load, not linearly. Lithium battery technologies, on the other hand, either provide the current they are rated at, at the voltage they are rated at, or their regulatory logic prevents it. Energizer e2 Photo Lithium provides up to 2.6A at 1.5V. You'll get close to the same duration whether you're pulling 100mA or 2A. If you try to put more than 2.6A, unlike a NiMH chemical battery which will "work, but drop voltage," it most likely will not at all, as the regulatory logic kicks in (possibly even killing its cells). This is so the battery does not combust. Alkaline, NiCD, NiMH and other battery technologies melt. They do not support combustion in our N-O environment. Lithium combusts. It doesn't quite "explode," but the effects can look like it. Originally Posted by Ash I've been caught recently having two sets of fully charged NiMH AAs (which are about a year old but have definitely been charged for less than 1000 times) and only been able to draw a total of 10 flashes between them at 1/2 power. NiCD was used for higher-current applications in the past, but they have serious memory effect and other issues. NiMH became far more commonplace because most applications -- such as AA -- are only 100-500mA loads. NiMH also has much longer charges in current-time than NiCD. Now that we're doing 1A+ in cameras, NiMH doesn't cut it as well. Virtually any brand other than Energizer or Sanyo Enelope is "half battery" (or worse) when I put them in, because they are not providing adequate current, and voltage is dropping. Energizer and Sanyo use over-charged designs to provide more real-time current. Energizer rates theirs as 2500mAh and I've measured them to provide over 1.5A at as high as 1.3V (1.2V is nominal), as does Energizer's own charges (see their site). Unfortunately the over-charge seems to "wear off" in a month, and the current-time drops to 1700mA and I'm getting 1A or less. Sanyo uses a more sustainable approach in their 2000mAh current-time designs, which drops less over time, but still provides 1.5A+ Unfortunately, NiMH is only 1.2V, so in a set of four (4), that's only 4.8V -- maybe 5.2V if you're getting 1.3V/unit at full charge (as both the Energizer NiMH charts show, and I have personally experienced). Your auto-focus motors and flash output is going to be far less at sub-5V versus the full 6V you'd get with 2x LiMg (CR-V3) or 4x LiFe (e2 Photo Lithium). There have even been reports of "cut out" when people use NiMH because the K100D/K200D voltage regulator doesn't like anything less than 5V. Normally a K100D/K200D should operate with 4.5-6.5V. Such cameras that can't work with 4.8V using Energizer/Sanyo NiMH fully charged should be returned to Pentax. BTW, I always drain'n charge my NiMH batteries, to measure the exact current-time. There is no way to measure "charge" otherwise, and the voltage output is only an "indicator," not exacting. And even then I still get a "mis-charge" in one (1) out of ten (10) NiMH batteries. All it takes is just one NiMH battery in the series circuit to be providing inadequate current for the entire set to drop voltage. All batteries in a series circuit must provide the adequate current/voltage or they all suffer. Regardless of what you use, just make sure the circuit never outputs more than 6.5V or you can damage the microelectronics. I have seen many, many posts on many forums were people gleefully talk about "how good" their AF motors are, but they have an occasional "issue" with the shutter, menu, etc... which means the microelectronics are being over-volted and the regulator can't deal with it. Pentax's regulator is only designed for 6.5V, and (seemingly, I haven't verified this though), a 4.5V cut-off. The latter won't damage the camera, it just won't power up. The former can easily damage the regulator and cause the unit to fail, and often will in order to protect the microelectronics. I.e., when I've designs boards, I design the regulator to fry before the microelectronics behind it -- especially if the regulator is on a different PCB or can otherwise be replaced easier than the "brains" behind it. I find paying $19 for twelve (12) Energizer e2 Photo Lithium batteries at Costco and Sam's Club is the "best buy" -- in my time, money and piece'of mind. That's for myself and my K100D. I honestly got tired of the "housekeeping" with NiMH, and carrying 3-5 sets. I found the AF.C mode at sporting/action events really drained them (AF.S was otherwise fine though). As I mentioned, I've designed microelectronic circuits myself. While I don't consider myself a "power" type of EE, I don't really care to risk my K100D to RCR-V3s which have an inherit compound that is almost a full volt over the maximum rated voltage on the K100D's regulator. Others may have a different opinion and swear by the aftermarket options they've chosen. Again, there is a reason why all Li-Ion batteries designed for all microelectronics are proprietary, and never use generic RCR-V3 (unlike non-rechargeable CR-V3s, which are LiMg, not Li-Ion). Then again, I'm the type that pays almost $40/each for the Pentax branded 7.2V/1600mAh Di50 batteries and the Pentax branded BK50 charger for the K10D/K20D. When it comes to Li-Ion, and the great variations, I just don't trust aftermarket. Statistics do show that even cheap Li-Ion batteries will, to an almost certainty, kill their own cells before combusting. But it's the little operational variations that I don't want damaging my K20D microelectronics over time, and I don't like to leave something to the smallest chance. But I used to work in aerospace, so I could be "overly anal." __________________ Bryan J Smith, Engineering Consultant, Photography Novice Striving for Amateur Abilities Pentax K20D, AF-360 FGZ, DA 10-17 f/3.5-4.5 FE, DA* 16-50 f/2.8, DA* 50-135 f/2.8, DA 50-200 f/4-5.6, FA 80-320 f/4.5-5.6 Taken with: Pentax K100D, DA 16-45mm f/4 Last edited by bjsmith; 08-03-2008 at 04:17 PM..