[Mangusta]

Hi guys

This is my first writing to this forum. I was searching Google to find out if other people also experience this problem. I am an electronics technician, and have found out what exactly causes this problem. So, if there still people out there struggling, let me know and I will help.

[goldenarrow]

Please do tell. Unless of course you are selling your knowledge to the highest bidder!

[MJL]

I use ist*DS2 for many years and notice it is very critical of battery type & mA. It work best on disposable lithium batteries and Sanyo Eneloop rechargeable. The batteries that show empty on the ist*DS2 display can still fire my flashes in full power for at least 10 shots!

[Mangusta]

I am an electronics engineer. I will gladly share my knowledge for free.

I have just bought a 2nd hand ist DL and have also experienced the battery "empty" problem. I have plugged a 6V, 4.5Ah sealed lead acid battery into the DC input terminal, and the camera worked fine. I then connected the same battery to the contacts where the AA batteries are inserted. It gave the same "empty" display. I then connected a 2200uF capacitor over the battery terminals, and it displayed battery full and the camera worked. It also works with AA batteries with the cap.

What happens here is that the camera draws a lot of current for a split second when it is switched on. It causes the battery voltage to dip for that split second to just under the low battery threshold, which is measured by it's micro processor. It decides that the battery is too weak to switch the camera on.

The capacitor works like a flywheel in which energy are stored. It can supply enough current for that split second so that the voltage does not dip too low.
I suspect that the internal capacitor is not doing it's job anymore. If it is a electrolytic cap, they tend to dry out if it is of poor quality.

The solution is to open the camera and find the cap and replace it, or to leave the original cap where it is and find a small space to just solder in a new cap in parallel with the + and - battery terminals. I have not determined yet what minimum capacitance is needed to solve the problem. It's voltage need not be higher than 6V. The size of a capacitor is determined by it's voltage and Farad value.

It will be difficult for non electronic or practical people to do this mod. I will be able to do it for a fee, but lives in South Africa, and I do not know what shipping will cost. I will be on holiday this coming week, so it will not help to write to me.

Shalom

[goldenarrow]

Mangusta,
This is excellent info! Thanks for sharing. I have some experience with soldering parts and an "old" K100D-S. Maybe I will go to Radio Shack and pick up the part and try it.....

GA

[MJL]

Hi Mangusta,

Thanks for the info. I will stick with disposable lithium batteries for now as they work better in cold Canadian outdoor. South Africa is sure beautiful & photogenic, wish I can visit your country again.

[widleaf]

Hi Mangusta,

Thank you very much for pointing out the root cause of this annoying issue. I have a few questions and hope you can help with.

1. I have the same problem with my rechargeable. But if I press down the flash button while I turn it on then it works. Do you know why this works?

2. Even use the above method, very often the battery gauge only displays two bars instead of three bars (battery was fully charged). I tried many new batteries and had the same result. Is this a different issue?

3. Is it difficult to find that capacitor? Can you provide some hint how to find it?


Thank you very much for your posting and helping everyone here.

[jedcat]

I, too, started experiencing this problem with my *ist DL which is why I searched and found this forum. I called Pentax tech support (800-877-0155) and spoke with "Randy". I described the problem and told him that is appears to be a known problem by the looks of the blogosphere. Randy suggested that a few blog posts don't indicate a consistent problem. I'm sending my camera body back to Pentax for examination and possible repair of the circuit board. I urge anyone else with one of these cameras who has experienced this power supply degradation to contact Pentax at the number above and report the issue so they can identify that it's not just a crackpot from Pennsylvania (me).

[Mangusta]

Hi Widleaf

Sorry for the delay, I was away for a while. To answer your questions:

1) Some batteries has a better "flywheel effect" than others. As I have explained, the microprosessor only takes samples of the batt voltage now and then. It is more concerned about the sudden drop in batt voltage when it is switched on than in a steady state lower voltage, which it should not be. By pressing another button when switching on, it seems that this sudden drop is cushened out a bit.
2) This is the same issue.
3) Capacitors is widely found in many electronic devices, equipment and electronic shops.

A cap will give that flywheel effect to filter out that sudden voltage drop. It should have it inbuild, and I am sure it has. I have add a small 470uF 6.3V Electrolytic cap to my ist DL by soldering it to the battery contacts inside the camera. The space is limited. The cap's fisical size is determined by it's uF value and its voltage rating. One should not go lower than 6V which is the battery voltage. One can go higher than 470uF if it will fit, or connect 2 of them in parallel. Polarity is important. A Ceramic type cap has the least leaking current, but the highest uF value it comes in is about 100uF, but one can connect as many as you like in parallel. Look for GRM series. I am not sure what the lowest uF value is which will cure the problem, but I would suspect a 100 to 220uF.

Bigest problem though are to open and close the Pentax without breaking or losing something. Some tips: The cap or caps must be added at the top of the camera where the batt contacts are, so start stripping at the top. And mark or document every screw's position. There is some unused space in the camera between the batteries. One can use 2 thin insulated wires from the battery terminals to mount the cap remotely and glue them to the plastic. Hope this helps!

[jselph]

I just experienced the same problem after letting my ist DL camera set up for a while. I found that I put a set of rechargables that I had used before in and they read dead after about 20 photos. I installed new alkalines and they showed dead immediately. I removed all batteries and "scrubbed" the battery contacts with a pencil eraser, blew out the residue and reinstalled the alkalines and they read full. Reinstalled the same rechargables that read dead and they read full. Went out to shoot a day of volleyball tournaments and those same batteries lasted all day and never showed below 50 percent.
I always look for the simple solution first, and in this case - it worked!

[Mangusta]

I agree that batt contacts can become dirty and should be cleaned, but with the ist DL, if you remove and install the same batteries 10 times in a row, you will get about 5 different readouts from die batt indicator. The camera's batt contacts are goldplated, and should not need cleaning, but if need be, be very carefull. Moisten an earbud with small amount of contact cleaner and gently rub contacts.

The ist DL also has a power jack input on it's side. You can use the same batteries which gives the low batt message, connect them in series and connect to the jack, and it will give a consistant batt full message.

[LTS]

My *ist DL began having these troubles earlier this month. I've always used Energizer Advanced LIthium batteries from the first time I bought the camera. Given that I took it to Costa Rica and took over 1000 photos in a week without killing the batteries I was sold.

So it's been odd that I've had these issues with the Lithium lately. I purchased one set.. no go. Purchased a second set.. no go. I put in new alkaline (generic) and the camera starts right up. I could switch one lithium into the set and more often than not the camera would fire up but if I put in two.. just the low battery flash.

So, after trying everything I could read I decided i would test the lithium batteries quick. I took out my flash and put in the 4 batteries and the thing fired up at blazing speed. I snapped off 4 flashes from the test and each time it would come back to ready almost instantaneously. Okay.. so the batteries are okay.

On a whim I put them back in the camera.. and boom it powered up. What?! So I took out my 2nd lithium set which had been bad. I put them in the camera and got the blink. I repeated the flash steps as above with the 2nd lithium set, put them back in the camera and boom it powered up. I can take the batteries out and put them back in and the camera starts up without any issue whatsoever.

I hope it stays.. but I thought I would post this as my experience for those who might be suffering.

[GibbyTheMole]

Actually, the Energizer 2200 to 2450 mah rechargeables are what I use in my *ist DS & K100D, and they work very well for me. I took around 1000 shots on my last vacation with my K100D & only needed to recharge once on the car charger. I don't use flash a lot, though, so that's probably a factor. (I just prefer natural light.)

I've used them pretty heavily for about a year and a half, only use the charger that came with them, and I don't mix battery types. in other words, I use a full set of 2450 mahs or a set of 2200 mahs, etc. Maybe that has something to do with it, I dunno.

Cheers,
Bobbo :-)

[UnknownVT]

My *ist DL began having these troubles earlier this month. I've always used Energizer Advanced LIthium batteries from the first time I bought the camera. Given that I took it to Costa Rica and took over 1000 photos in a week without killing the batteries I was sold.

So it's been odd that I've had these issues with the Lithium lately. I purchased one set.. no go. Purchased a second set.. no go. I put in new alkaline (generic) and the camera starts right up. I could switch one lithium into the set and more often than not the camera would fire up but if I put in two.. just the low battery flash.

So, after trying everything I could read I decided i would test the lithium batteries quick. I took out my flash and put in the 4 batteries and the thing fired up at blazing speed. I snapped off 4 flashes from the test and each time it would come back to ready almost instantaneously. Okay.. so the batteries are okay.

On a whim I put them back in the camera.. and boom it powered up. What?! So I took out my 2nd lithium set which had been bad. I put them in the camera and got the blink. I repeated the flash steps as above with the 2nd lithium set, put them back in the camera and boom it powered up. I can take the batteries out and put them back in and the camera starts up without any issue whatsoever.

I hope it stays.. but I thought I would post this as my experience for those who might be suffering.

OK I think this is to do with a phenomena of primary lithium that are left idle/dormant requiring "waking up" to regain their performance.

I knew I had read this somewhere like the battery section in CPF (CandlePowerForums) but could not find the reference.

Eventually I found a reference by doing a google of lithium primary dormant and found this:

[PDF] Passivation of Primary Lithium Cells

By putting the lithium batteries into the flashgun in effect wakes them up by high current draw - whereas putting them in the *ist DL only draws a a lowish current to meter their state, but obviously not enough to overcome the passivity of the batteries.

[opfor]

I've been using Energizer rechargeable batteries in my DL for years. My charger has a discharge function, so from military experience where we were taught to always discharge completely before recharging, I usually get close to two years per set. The discharge setting is basically using the test switch till the light goes out (funny what you find when you read the directions). It really makes it easy to see which battery in a set is failing first if it is the only one in a set that has no charge left every time. A piece of tape works well to mark a suspect battery.
I started with two sets and added a third when batteries started to go. That way I always had two complete sets and one or two extra batteries.
Rechargeable batteries need to be discharged before recharging to stay healthy. If all else fails, you can use a flashlight bulb if your charger won't discharge them. Solder one piece of wire to the barrel of the bulb and one to the bottom tip. Then it is just a simple thing to use electrical tape to connect the wires to the poles(ends) of the battery.