Why you shouldn't store your Pentax without the main battery

**Papa_Joe** · 06-09-2021, 02:32 AM - **1 Like**

My old ist D* is used every then and now and rests in its box most of the time since more than 5 years. There is always a set of low self discharge rechargable batteries (a.k.a eneloop) in it. And it still uses the first backup battery. There is no issue in leaving NiMH batteries in the camera. They will not leak in the way like ordinary batteries. In over 30 years using rechargable batteries I had not one case of a leaking one.
Charging up the eneloops every half year is sufficient.

My K-10D stays in its box since ober one year now. Same procedure as with my ist D* I only have to charge the Li-Io batteries more often. Much better then drainig the byckup battery to death.

**photogem** · 06-09-2021, 03:45 AM

Originally posted by Papa_Joe

My old *ist-D is used every then and now and rests in its box most of the time since more than 5 years.
There is always a set of low self discharge rechargable batteries (a.k.a Eneloop) in it. And it still uses the first backup battery.
There is no issue in leaving NiMH batteries in the camera. They will not leak in the way like ordinary batteries.
In over 30 years using rechargable batteries I had not one case of a leaking one. Charging up the eneloops every half year is sufficient.

My K-10D stays in its box since ober one year now. Same procedure as with my *ist D. I only have to charge the Li-Io batteries more often.
Much better then drainig the backup battery to death.

Exactly.

It was THIS THREAD with claims just not proofen but an insistance that keeping a Li-Ion or Eneloops inside one's Pentax is dangerous which brought me to start this one because quite sometimes I came across Pentax bodies with drain back-up battery and every time and then this problem was discussed here in the forum and in other ones all over the world.

The main problem is that Pentax had recommended to leave the main battery outside when storing it but I guess this is a residue from ancient times when people still used non-rechargeable batteries. Then one indeed could have the problem of those leaking.

NiMH hardly leak but it can happen due to abuse:
What could cause leakage in Ni-MH rechargeable batteries? | Panasonic eneloop
The problem is that they have a vent so gas can come out.
In some NiMH's it has happened that when they were stored for a long time with the plus-pole downwards, the vent got stuck and thus they started to leak. But this was very rare and with Eneloops it shouldn't happen at all.

The person claiming in the other thread that socalled "American specialists" warn about leaving batteries inside devices uses Eneloops in his K30, so nothing to worry at all.

Roco Kiefa · 03-20-2023, 10:48 AM

I've bought an old K10D recently.
It loses time and date after replacing the main battery.
Is there any manual how to change these tiny Lithium-Battery?

kypfer · 03-20-2023, 03:39 PM

Originally posted by Roco Kiefa

I've bought an old K10D recently.
It loses time and date after replacing the main battery.
Is there any manual how to change these tiny Lithium-Battery?

It's a major disassembly and then some precision soldering needed. Hardly worth the effort or the risk of permanent damage.
I have two cameras with this problem, one of which is in regular use, the other only used occasionally.
The former, I simply spend the extra few seconds resetting the clock and calendar as required when I change the battery, no other settings are "lost".
The latter, much the same 'cept I don't keep the battery fitted so it doesn't go flat

Roco Kiefa · 03-21-2023, 05:09 AM

ok - so it seems I have to deal with it ... sad.
But I think this problem appears to the most old cameras that were buyed second hand. Most of the people think, that it it much saver to store the camera without the main battery inside.

I have a little workaround: I juse the K10D only with the camery grip. So I can always change the battery in the grip and the battery in the camera always stays fully charged.

**photogem** · 03-21-2023, 02:27 PM

Originally posted by Roco Kiefa

I've bought an old K10D recently.
It loses time and date after replacing the main battery.
Is there any manual how to change these tiny Lithium-Battery?

To disassemble a Pentax K10D is pretty easy:
If you follow the instructions how to do it with the K30 here:
Manual solenoid replacement Pentax K30 / Discharge flash-condenser / Solenoid choice - PentaxForums.com

There are instructions for the K10D:
Disassembly And Assembly Procedures; Disassembly Procedure Of Main Body - Pentax K10D 76830 Service Manual [Page 9] | ManualsLib

It is easier with the K10D as there is only one hidden screw: Deep down in the battery compartment.
Then you just need to take the back off as well which is straight forward and then you have access to the mainboard:
Disassemble the Pentax K10D - PentaxForums.com

The small battery, a 3V lithium cell, is located at the center of the mainboard.
If you just clip one contact off it can't suck your main battery empty anymore.
No danger in doing so.

To replace it demands very good soldering experience, then study how it is done with the K30:
Tutorial: Change Back-up Battery Pentax K-30, K-50, K-500 - PentaxForums.com

Roco Kiefa · 03-22-2023, 04:06 AM

Thank you for your help.

But it seems that the buffer-battery in the K10D sits on the inner side of the mainboard (see picture from the service manual)

Attached Images

**photogem** · 03-22-2023, 05:37 AM

Well observed.

I never had a K10D mainboard out, never needed to. The picture which I had was too small.
So you have to loosen the Mainboard and see if you can get to the battery without having to unsolder wires.
If you need to solder, the mainboard is large and easy to access the wires. Very different to the K-S1/2 or K70.

bugeye59 · 09-26-2023, 04:13 PM

I have had a charged battery in my K-50 camera for several months with minimal use during this time. Naturally, the Lion batteries need refreshing over these long periods and I do so recharge on occasion. But I fail to see the connection to the long term Lithium 3V Seiko MS414GE located on the motherboard.

Sure, over a 10 year period these long term batteries will require replacement, but I can see no relation to the normal power batteries.

35mmfilmfan · 09-26-2023, 04:20 PM

Originally posted by bugeye59

I have had a charged battery in my K-50 camera for several months with minimal use during this time. Naturally, the Lion batteries need refreshing over these long periods and I do so recharge on occasion. But I fail to see the connection to the long term Lithium 3V Seiko MS414GE located on the motherboard.

Sure, over a 10 year period these long term batteries will require replacement, but I can see no relation to the normal power batteries.

As I understand it, the power from the main battery (of whatever type) keeps the internal battery charged, so that the settings info is not lost. So, if the camera is left without the main battery for an extended period, the internal battery will lose its charge.

bugeye59 · 09-26-2023, 05:31 PM

If this is the case then why would leaving the main batteries in the camera cause a problem?

The Lion main batteries will maintain a nominal 3.6 volt charge for a very long time (like over a year).

If your not using your Pentax in this amount of time then there are other issues!

Wheatfield · 09-26-2023, 08:08 PM

Originally posted by bugeye59

If this is the case then why would leaving the main batteries in the camera cause a problem?

The Lion main batteries will maintain a nominal 3.6 volt charge for a very long time (like over a year).

If your not using your Pentax in this amount of time then there are other issues!

The problem is leaving the camera without a main battery in it for an extended period of time.
The issue I had was the K1 supplanting my K3, which then sat unused for over 3 years with no main battery which was enough time to kill the internal one.

**photogem** · 10-17-2023, 07:28 PM

Originally posted by Wheatfield

The problem is leaving the camera without a main battery in it for an extended period of time.
The issue I had was the K1 supplanting my K3, which then sat unused for over 3 years with no main battery which was enough time to kill the internal one.

That's the whole point, see the headline of this thread.

As soon as the C-MOS is dead, it still tries to recharge and thus drains energy of the main Li-Ion battery.
See:
Pentax K30 battery life - camera turned off - PentaxForums.com

C-MOS batteries in the K10D, K20D, K7/5/3/1 have a larger capacity, this is one reason why this problem doesn't happen there so often.
But when it happens, it is more work because the C-MOS is on the backside of the mainboard.
This is the reason why some workshops don't dare to do change it but change the complete mainboard.

But we had a few DIY'ers here on the forum who dared to and managed fine.

**tfa** · 01-06-2024, 03:58 AM

Hi, interesting read, it seems the main problem is in soldering once the cmos battery is located and the heat problems associated with that. Does anyone have any experience with the electrically conductive glue that seems to be available these days?
It would be a different out come if this method was shown to be practical.

**photogem** · 01-06-2024, 04:33 AM

Originally posted by tfa

Hi, interesting read, it seems the main problem is in soldering once the cmos battery is located and the heat problems associated with that. Does anyone have any experience with the electrically conductive glue that seems to be available these days?
It would be a different out come if this method was shown to be practical.

When the CMOS is on the backside of the mainboard, there is a lot of soldering required.
I would not recommend to re-solder with concuctive glue.
If you manage to unsolder those wires, resoldering is the least problem.

The bigger problem is with the more modern Pentax DSLR's since the K-S1, K-S2 etc.
Their mainboards are smaller, everthing is very tight.
Soldering there is super tricky. I have done very fine soldering (under the microscope partly) but here it is different.
Too many critical parts very close to the soldering points, very easy to do damage.

01-06-2024, 03:58 AM	#29
tfa Site Supporter Join Date: Nov 2023 Location: Southern Limestone Coast Blue Lake territory Posts: 11	battery drain? Hi, interesting read, it seems the main problem is in soldering once the cmos battery is located and the heat problems associated with that. Does anyone have any experience with the electrically conductive glue that seems to be available these days? It would be a different out come if this method was shown to be practical.

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06-09-2021, 02:32 AM - 1 Like	#16
Papa_Joe Site Supporter Join Date: Sep 2018 Location: SW Bavaria Posts: 562	My old ist D* is used every then and now and rests in its box most of the time since more than 5 years. There is always a set of low self discharge rechargable batteries (a.k.a eneloop) in it. And it still uses the first backup battery. There is no issue in leaving NiMH batteries in the camera. They will not leak in the way like ordinary batteries. In over 30 years using rechargable batteries I had not one case of a leaking one. Charging up the eneloops every half year is sufficient. My K-10D stays in its box since ober one year now. Same procedure as with my ist D* I only have to charge the Li-Io batteries more often. Much better then drainig the byckup battery to death.

06-09-2021, 03:45 AM	#17
photogem Site Supporter Join Date: Apr 2015 Posts: 3,522 Original Poster	Originally posted by Papa_Joe My old ist-D is used every then and now and rests in its box most of the time since more than 5 years. There is always a set of low self discharge rechargable batteries (a.k.a Eneloop) in it. And it still uses the first backup battery. There is no issue in leaving NiMH batteries in the camera. They will not leak in the way like ordinary batteries. In over 30 years using rechargable batteries I had not one case of a leaking one. Charging up the eneloops every half year is sufficient. My K-10D stays in its box since ober one year now. Same procedure as with my ist D. I only have to charge the Li-Io batteries more often. Much better then drainig the backup battery to death. Exactly. It was THIS THREAD with claims just not proofen but an insistance that keeping a Li-Ion or Eneloops inside one's Pentax is dangerous which brought me to start this one because quite sometimes I came across Pentax bodies with drain back-up battery and every time and then this problem was discussed here in the forum and in other ones all over the world. The main problem is that Pentax had recommended to leave the main battery outside when storing it but I guess this is a residue from ancient times when people still used non-rechargeable batteries. Then one indeed could have the problem of those leaking. NiMH hardly leak but it can happen due to abuse: What could cause leakage in Ni-MH rechargeable batteries? \| Panasonic eneloop The problem is that they have a vent so gas can come out. In some NiMH's it has happened that when they were stored for a long time with the plus-pole downwards, the vent got stuck and thus they started to leak. But this was very rare and with Eneloops it shouldn't happen at all. The person claiming in the other thread that socalled "American specialists" warn about leaving batteries inside devices uses Eneloops in his K30, so nothing to worry at all.

03-20-2023, 10:48 AM	#18
Roco Kiefa New Member Join Date: Mar 2023 Posts: 6	I've bought an old K10D recently. It loses time and date after replacing the main battery. Is there any manual how to change these tiny Lithium-Battery?

03-20-2023, 03:39 PM	#19
kypfer Pentaxian Join Date: Jan 2018 Location: Jersey C.I. Posts: 3,595	Originally posted by Roco Kiefa I've bought an old K10D recently. It loses time and date after replacing the main battery. Is there any manual how to change these tiny Lithium-Battery? It's a major disassembly and then some precision soldering needed. Hardly worth the effort or the risk of permanent damage. I have two cameras with this problem, one of which is in regular use, the other only used occasionally. The former, I simply spend the extra few seconds resetting the clock and calendar as required when I change the battery, no other settings are "lost". The latter, much the same 'cept I don't keep the battery fitted so it doesn't go flat

03-21-2023, 05:09 AM	#20
Roco Kiefa New Member Join Date: Mar 2023 Posts: 6	ok - so it seems I have to deal with it ... sad. But I think this problem appears to the most old cameras that were buyed second hand. Most of the people think, that it it much saver to store the camera without the main battery inside. I have a little workaround: I juse the K10D only with the camery grip. So I can always change the battery in the grip and the battery in the camera always stays fully charged.

03-21-2023, 02:27 PM	#21
photogem Site Supporter Join Date: Apr 2015 Posts: 3,522 Original Poster	Originally posted by Roco Kiefa I've bought an old K10D recently. It loses time and date after replacing the main battery. Is there any manual how to change these tiny Lithium-Battery? To disassemble a Pentax K10D is pretty easy: If you follow the instructions how to do it with the K30 here: Manual solenoid replacement Pentax K30 / Discharge flash-condenser / Solenoid choice - PentaxForums.com There are instructions for the K10D: Disassembly And Assembly Procedures; Disassembly Procedure Of Main Body - Pentax K10D 76830 Service Manual [Page 9] \| ManualsLib It is easier with the K10D as there is only one hidden screw: Deep down in the battery compartment. Then you just need to take the back off as well which is straight forward and then you have access to the mainboard: Disassemble the Pentax K10D - PentaxForums.com The small battery, a 3V lithium cell, is located at the center of the mainboard. If you just clip one contact off it can't suck your main battery empty anymore. No danger in doing so. To replace it demands very good soldering experience, then study how it is done with the K30: Tutorial: Change Back-up Battery Pentax K-30, K-50, K-500 - PentaxForums.com

03-22-2023, 04:06 AM	#22
Roco Kiefa New Member Join Date: Mar 2023 Posts: 6	Thank you for your help. But it seems that the buffer-battery in the K10D sits on the inner side of the mainboard (see picture from the service manual) Attached Images

03-22-2023, 05:37 AM	#23
photogem Site Supporter Join Date: Apr 2015 Posts: 3,522 Original Poster	Well observed. I never had a K10D mainboard out, never needed to. The picture which I had was too small. So you have to loosen the Mainboard and see if you can get to the battery without having to unsolder wires. If you need to solder, the mainboard is large and easy to access the wires. Very different to the K-S1/2 or K70.

09-26-2023, 04:13 PM	#24
bugeye59 Junior Member Join Date: Mar 2022 Location: Philadlephia Posts: 34	I have had a charged battery in my K-50 camera for several months with minimal use during this time. Naturally, the Lion batteries need refreshing over these long periods and I do so recharge on occasion. But I fail to see the connection to the long term Lithium 3V Seiko MS414GE located on the motherboard. Sure, over a 10 year period these long term batteries will require replacement, but I can see no relation to the normal power batteries.

09-26-2023, 04:20 PM	#25
35mmfilmfan Pentaxian Join Date: Oct 2016 Location: Norfolk, UK Posts: 4,338	Originally posted by bugeye59 I have had a charged battery in my K-50 camera for several months with minimal use during this time. Naturally, the Lion batteries need refreshing over these long periods and I do so recharge on occasion. But I fail to see the connection to the long term Lithium 3V Seiko MS414GE located on the motherboard. Sure, over a 10 year period these long term batteries will require replacement, but I can see no relation to the normal power batteries. As I understand it, the power from the main battery (of whatever type) keeps the internal battery charged, so that the settings info is not lost. So, if the camera is left without the main battery for an extended period, the internal battery will lose its charge.

09-26-2023, 05:31 PM	#26
bugeye59 Junior Member Join Date: Mar 2022 Location: Philadlephia Posts: 34	If this is the case then why would leaving the main batteries in the camera cause a problem? The Lion main batteries will maintain a nominal 3.6 volt charge for a very long time (like over a year). If your not using your Pentax in this amount of time then there are other issues!

09-26-2023, 08:08 PM	#27
Wheatfield Moderator Join Date: Apr 2008 Location: The wheatfields of Canada Posts: 15,986	Originally posted by bugeye59 If this is the case then why would leaving the main batteries in the camera cause a problem? The Lion main batteries will maintain a nominal 3.6 volt charge for a very long time (like over a year). If your not using your Pentax in this amount of time then there are other issues! The problem is leaving the camera without a main battery in it for an extended period of time. The issue I had was the K1 supplanting my K3, which then sat unused for over 3 years with no main battery which was enough time to kill the internal one.

10-17-2023, 07:28 PM	#28
photogem Site Supporter Join Date: Apr 2015 Posts: 3,522 Original Poster	Originally posted by Wheatfield The problem is leaving the camera without a main battery in it for an extended period of time. The issue I had was the K1 supplanting my K3, which then sat unused for over 3 years with no main battery which was enough time to kill the internal one. That's the whole point, see the headline of this thread. As soon as the C-MOS is dead, it still tries to recharge and thus drains energy of the main Li-Ion battery. See: Pentax K30 battery life - camera turned off - PentaxForums.com C-MOS batteries in the K10D, K20D, K7/5/3/1 have a larger capacity, this is one reason why this problem doesn't happen there so often. But when it happens, it is more work because the C-MOS is on the backside of the mainboard. This is the reason why some workshops don't dare to do change it but change the complete mainboard. But we had a few DIY'ers here on the forum who dared to and managed fine.

01-06-2024, 04:33 AM	#30
photogem Site Supporter Join Date: Apr 2015 Posts: 3,522 Original Poster	Originally posted by tfa Hi, interesting read, it seems the main problem is in soldering once the cmos battery is located and the heat problems associated with that. Does anyone have any experience with the electrically conductive glue that seems to be available these days? It would be a different out come if this method was shown to be practical. When the CMOS is on the backside of the mainboard, there is a lot of soldering required. I would not recommend to re-solder with concuctive glue. If you manage to unsolder those wires, resoldering is the least problem. The bigger problem is with the more modern Pentax DSLR's since the K-S1, K-S2 etc. Their mainboards are smaller, everthing is very tight. Soldering there is super tricky. I have done very fine soldering (under the microscope partly) but here it is different. Too many critical parts very close to the soldering points, very easy to do damage.