[tokyoscape]

Hi there. I have not used my K3 in a while, and finally picked it back up the other day. It no longer remembers the date/time and wants it reset every time I turn on. Is there a simple solution to this? Thanks!

Same problem! Leave main battery in the body and leave it on will work only about 3-4 days. Longer than that the camera will forget the time/date setting. I don't have a solution but reset the date every time I want to use my camera. Don't care about the time.

[StigVidar]

I agree it charges slowly, but it is at least "maintained" with a battery in place- even when not turned on; i.e. it does not discharge as long as the main battery is charged and present.

No battery or depleted main battery and the internal battery will definitely discharge after a few days or weeks.

I agree on that. With a main battery installed the backup battery could be "maintained". This discussion is about K-3, but I have a Q7 and this camera does not maintain the backup battery even if the main battery is installed. Q7 have to be used regularly.

I wonder why they decided to use small batteries for this. A small super capacitor would probably be more reliable and could keep the clock running for a few hours while charging the main battery.

[photogem]

I agree on that. With a main battery installed the backup battery could be "maintained". This discussion is about K-3, but I have a Q7 and this camera does not maintain the backup battery even if the main battery is installed. Q7 have to be used regularly.

I wonder why they decided to use small batteries for this. A small super capacitor would probably be more reliable and could keep the clock running for a few hours while charging the main battery.

I agree, a super-cap might be a better choice.
I had bad results just swapping the MS414 for a ELNA supercap in a K30. Somebody claimed that it worked fine for him but in my case, the main battery got drained.
But it might have been my fault:
The ELNA is 1,8mm thick while the Seiko MS414 has 1,65mm
Because the top is plus, it might have shortened as I found out later through member @Philber HERE
So next time I open a K100D or K200D I will replace the MS414 for this Elna supercap and test again.
I won't do that on a K30 because there soldering is just a but critical but I will try conductive glue. I never liked that stuff but here it might be worth trying again.

I have come across a few K30/K50's with drained CMOS batteries in the past 18 month!

Usually because the users stored them for lets say 6month, particular during inability to go have holidays/travel/shutdowns.

So the solenoid stuck: ABF. But then I noticed the drained CMOS.
One of my sons has a K30 (with Japansolenoid). He knows about storing it with the battery, it is a very early model. I think he hasn't used it
for over two years now, it just isn't his thing... he takes photos with the smartphone if needed.
But the memory battery is still alright. He recharges the main battery every 6 month or so...or I do it when I visit him!

I have a K10D which is much older. I hardly use it but store it with the main battery.
Never any problem with the CMOS.
Same last year with my backup K5 which I had always in the car, even in extrem temperatures.
Hardly used that last year before I sold it. It is stored anyway with 2 D-LI90's and I swap them and charge the other one.
CMOS 100% alright.
With my KP and K3 it is different, I use them pretty much every second day or so.


I prefer not having to exchange the CMOS on a K5 or K3 series! Taking the mainboard out is a lot of soldering.
But at least since about a week I have the latest Weller WSP80 soldering iron, great tool.

so back to the thread opener and @doroth2:
Read here:
https://www.pentaxforums.com/forums/114-maintenance-repair-articles/426486-m...p-battery.html
Maybe it works

[doroth2]

Wow. Thanks everyone. I think I had it stored without the battery. That sucks. I wish I had known. I don’t think changing the internal battery is something I can do, so I guess I’ll be resetting the date a lot. It resets every time the camera is turned off or goes to sleep, not just when I charge the battery. I love my k3! I’m so frustrated about this!

---------- Post added 06-17-21 at 04:33 PM ----------

So, yesterday I put in a freshly charged battery, set the date and time, and turned the camera off. Today, it remembers the date and time! Woohoo! Hopefully it keeps remembering.

[alfa75ts]

and turned the camera off. Today, it remembers the date and time! Woohoo! Hopefully it keeps remembering.

Sadly that's normal behavior, it's removing the battery that's the test.


The specs on the MS414 show that it can be discharged to 0 volts 100 times but they do not specify how long it can stay at zero without damaging the battery, might be a very short time or it might be a month.

Best thing is to keep a charged battery in the camera at all times.

[stevebrot]

Sadly that's normal behavior, it's removing the battery that's the test.


The specs on the MS414 show that it can be discharged to 0 volts 100 times but they do not specify how long it can stay at zero without damaging the battery, might be a very short time or it might be a month.

Best thing is to keep a charged battery in the camera at all times.

Thanks for dropping in with this information. I have wondered whether the AC adapter for the K-3 might stand in while the battery is charging. I know that mine will run the camera without a battery installed.


Steve

[Not a Number]

It's actually only 50 recharge cycles from 100% depth of discharge vs 500 @ 20% dod.

MS414GE | Seiko Instruments Inc. Micro Energy Division

[alfa75ts]

It's actually only 50 recharge cycles from 100% depth of discharge vs 500 @ 20% dod.

Pretty sure the spec sheet I saw said 100 but maybe not.

The point was mainly that the time at zero before damaging the battery is not specified.

I have wondered whether the AC adapter for the K-3 might stand in while the battery is charging.

Steve, I have left the camera (K7, K3) without a battery overnight hundreds of times without a problem. I have left it longer than that once or twice and had to reset the clock but the internal battery recharged after putting a charged battery in (the internal battery may not have been completely flat).

[photogem]

Pretty sure the spec sheet I saw said 100 but maybe not.

The point was mainly that the time at zero before damaging the battery is not specified.

Steve, I have left the camera (K7, K3) without a battery overnight hundreds of times without a problem. I have left it longer than that once or twice and had to reset the clock but the internal battery recharged after putting a charged battery in (the internal battery may not have been completely flat).

The MS414 has a cycle life(d.o.d) of 50x

the MS518 has 100x

You were just lucky with the K7 and K3 because the have the MS518 but it can hit it as well, we had cases here in the forum when it hit the CMOS of the K3. So telling others that it never happened to you is kind of telling "I smoked all my life but nothing ever happened".

@stevebrot: The AC adapters won't charge the main (Li-Ion) battery, so I question it will charge the CMOS.

[alfa75ts]

So telling others that it never happened to you is kind of telling "I smoked all my life but nothing ever happened".

But that is not what I'm saying, I am saying that if you allow the internal battery to remain 'flat' too long you will not be able to recharge it. Nothing to do with the cycle life (but that's another limit you could hit), just simply flat too long.

[stevebrot]

@stevebrot: The AC adapters won't charge the main battery, so I question it will charge the CMOS.

It may not need to charge the MS621. All it needs to do is to keep the board powered so that the MS621 is not tapped. I am assuming that the clock usually draws from main board power with the MS621 serving as back-up when the main board is not powered. Just a thought, but one that probably has only limited practical application.


Steve

[photogem]

But that is not what I'm saying, I am saying that if you allow the internal battery to remain 'flat' too long you will not be able to recharge it. Nothing to do with the cycle life (but that's another limit you could hit), just simply flat too long.

Then maybe I misunderstood.
When you wrote:

I have left the camera (K7, K3) without a battery (D-LI90) overnight hundreds of times without a problem. I have left it longer than that once or twice and had to reset the clock but the internal battery (C-MOS) recharged after putting a charged battery (D-LI90) in (the internal battery (C-MOS) may not have been completely flat).

This indicates that the internal C-MOS battery is already quite low!
Why? Well, mainly because you stored it as your wrote.

It does recharge because it is not "totally at its end" but actually could be dead very soon.
The K3 and K7 have the higher capacity Seiko MS518, as does the K5 and possibly K1 and maybe KP.
But all the others have the lower capacity Seiko MS414 which draines quicker.

So to say: "I did it and nothing happened" I understand similar to "I smoked all my life and nothing happened" (while actually already quite a bit
has happened... relative to your CMOS which is drained quite a bit)


In general, it is just best to store one's Pentax with the internal Li-Ion or Eneloop, there is zero danger.
And not to write comments "but it worked with me" (kind of misleading others)

[alfa75ts]

When you wrote:

Originally posted by alfa75ts
I have left the camera (K7, K3) without a battery overnight hundreds of times without a problem. I have left it longer than that once or twice and had to reset the clock but the internal battery recharged after putting a charged battery in (the internal battery may not have been completely flat).

Which was directly in response to Steve's question:

I have wondered whether the AC adapter for the K-3 might stand in while the battery is charging.

The internal battery should not go flat in the time it takes to charge a battery, any battery. Or even overnight as I indicated in my example. I have probably left the battery out of my K3 overnight 1000+ times in six years with no issues. And there should be no issues, Pentax must have expected the internal battery to hold a charge long enough to recharge a battery with time to spare, no need for an AC adapter while charging a battery.

[photogem]

Which was directly in response to Steve's question

Any statement or claim, no matter if as a response or not is in written form in the internet.

The internal battery should not go flat in the time it takes to charge a battery, any battery. Or even overnight as I indicated in my example. I have probably left the battery out of my K3 overnight 1000+ times in six years with no issues.

Wrong: You had issues: You drained your CMOS that low that you had to set the time again.
To me a serious issue. Your CMOS battery is near an anorexic state.
Next time it might not get up on its tiny little feet anymore!

And there should be no issues

But there are issues!

Pentax must have expected the internal battery to hold a charge long enough to recharge a battery with time to spare

That's wishfull thinking. The recommendations of Pentax to not store the body with battery stems from old days when Alkaline's could leak and did leak.
These days cars, smartphones, clocks, smokedetectors etc. are built with internal Li-Ions which cannot be removed.
Particular with smoke-detectors you'd think they didn't construct those to detect a fire resulting from exploding Li-Ions.....

Manufacturers might even take into account that certain parts should not live forever because they wish you'd be that pissed of with your old body
you wish for a healthy young new one..... being up to date....

.... no need for an AC adapter while charging a battery.

You didn't understand that either:
The AC-Adapter cannot charge the battery! I thought I made that quite clear.

Post #4 in this thread by @boriscleto shows that it can be a very serious issue and for the TO it is an issue.
The CMOS of your K3 is near to an issue, claiming "there should be no issues" is like claiming "there should be no issues if you smoke because my lungs are doing fine..." (no misused lung is doing fine and no misused CMOS is doing fine)

[stevebrot]

The AC-Adapter cannot charge the battery! I thought I made that quite clear.

Glad you tested that. Thanks! (assuming you mean the backup CMOS battery which might already topped off when the main battery is removed and may not be the source of clock power until then).

I suspect the only way to know for sure might be with a patent search where these things are spelled out using state diagrams.


Steve