[EnglishBob]

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My dad was a maintainability engineer for Martin and then Westinghouse Underseas. Ricoh did not plan for this battery to be replaced. My dad spent his whole life arguing about designs like this.

[fayssal]

The first video has been prooved wrong already here on the forum!
The second is worth nothing, because all videos by those digi-service guys are just to confuse but not to help!

So base don which personal experience is your own proof?

I didn't try to replace battery because I find it less complicated to live with that issue by replacing main battery rapidely, it tooks me 4 or 5 seconds

[stevebrot]

right one in front of me, I have two of them.
The backup battery is on the backside of the mainboard, which in this case I shall not take of because this one needs replacement of the display.

Very good.

I wonder why they seem to be a problem. The clock chip draws precious little current.


Steve

[photogem]

I wonder why they seem to be a problem. The clock chip draws precious little current.

The problem usually occurs when the camera is left without battery for a long time unused.
The "draw" is enough over a long time to discharge the battery.
For this there should be some notice in the menu to store the body with the Li-Ion battery only

[stevebrot]

The problem usually occurs when the camera is left without battery for a long time unused.

I just looked at the spec for the MS414 and its capacity is only 2 mAh into a standard rated 0.01 mA. If drawn at the standard rate, it might well completely discharge to zero while the main battery is out for charging.* If that pattern is the norm, the cycle life of the battery may be severely reduced to the specification's estimate of only 50 cycles.

Yes, a caution would definitely be in order, preferably on the inside lid of the battery chamber in bright yellow.

As preventive, having the camera on external power if the battery is out for an extended time might be effective.


Steve

* When mine go on the charger, they might be there for a day or so, but I swap in an immediate backup into the camera.

[EnglishBob]

Swapping batteries fast is the best option. So far, so good.

[pkboy]

Swapping batteries fast is the best option. So far, so good.

Yes, I found this to be the case for me too.

[mroeder75]

I will chime in here. I purchased a second-hand K-3 in December, and it forgets the time. It had a very low shutter count and shipped from Japan without a battery in it.
I reset the time and date either yesterday, and yet every photo nevertheless is dated in 2013.
Tonight reset it about 1.5 hours ago and left the camera on until it automatically shut off. So far, for 1.5 hours it has remembered the date. We shall see what tomorrow brings.

[35mmfilmfan]

Not (yet !) had this issue myself, but I use my K3 with a Neewer battery grip, grip battery selected first, and I always travel with spares, so if the grip battery depletes, I can swap it while the camera battery keeps things running. Once a month, I charge all my spares (I am OCD about spare cards and batteries !), swap the ones in the grip and body with fully charged ones, then charge the ones I have removed. Done this with previous cameras too (K10, K20) and all has been well. I even have Eneloops in the AA tray for the K3 grip, in case the others have problems. Mind you, at my age, forgetting the date is the least of my worries !

[photogem]

I will chime in here. I purchased a second-hand K-3 in December, and it forgets the time. It had a very low shutter count and shipped from Japan without a battery in it.
I reset the time and date either yesterday, and yet every photo nevertheless is dated in 2013.
Tonight reset it about 1.5 hours ago and left the camera on until it automatically shut off. So far, for 1.5 hours it has remembered the date. We shall see what tomorrow brings.

I'd recommend the cheap external PS and leave it on for 24 hrs or longer.
A noname product is fine, such as this one:
HQRP AC Adapter for Pentax K-AC132 38780 K-3, K-5II, K-5IIs Power Supply Cord 884667419487 | eBay

It seems the internal MS414 battery is not completly depleted and has that leftover capacity that it can recharge over time.
So just never leave the K3 without its main battery for a long time!

I think 1,5 hrs are not quite long enough.
But you don't want to risk depletion of your Pentax D-LI90.
I think if you set the K3 for "no Auto-Switch off" it will switch still autmatically off before the D-LI90 is in danger.

@35mmfilmfan: Thats how I did it with my K3's and K5's as well and I liked the possibility to have AA's as well because in the Alps we had sometimes very low temperatures in winter (it changes though). AA's are that much more reliable then.
But the problem we are speaking here about is about the internal battery on the back of the mainboard, a tiny MS414 3V battery.

[mroeder75]

I'd recommend the cheap external PS and leave it on for 24 hrs or longer.
A noname product is fine, such as this one:
HQRP AC Adapter for Pentax K-AC132 38780 K-3, K-5II, K-5IIs Power Supply Cord 884667419487 | eBay

It seems the internal MS414 battery is not completly depleted and has that leftover capacity that it can recharger over time.
So just never leave the K3 without its main battery for a long time!

I think 1,5 hrs are not quite long enough. But you don't want to risk depletion of your Pentax D-LI90 although I think if you set the K3 for

no Auto-Switch off it goes off before the battery is in danger.

@35mmfilmfan: Thats how I did it with my K3's and K5's as well and I liked the possibility to have AA's as well because in the Alps we had sometimes very low temperatures in winter (it changes though). AA's are that much more reliable then.
But the problem we are speaking here about is about the internal battery on the back of the mainboard, a tiny MS414 3V battery.

Thank you. I took the camera on a trip 2-weeks ago, and it didn't remember dates. Now it has been a week since I returned and turned it on. Today, the date and time are correct! So whatever you and I have done works, but I did not purchase a power supply. I look at my historical photos over the past 6-weeks since acquiring the camera and heretofore the camera, at least in the photos it produced, never remembered the date I set it to.

Date and time are important since I am an attorney. I want correct times and dates on my work photos, as you might understand. Since now it seems to work do you think I can get buy without a power supply for the clock battery? Or will my camera battery do the job from here?

[photogem]

Date and time are important since I am an attorney. I want correct times and dates on my work photos, as you might understand. Since now it seems to work do you think I can get buy without a power supply for the clock battery? Or will my camera battery do the job from here?

I'd try it first with the Li-Ion. As soon as the clock-battery has enough charge and you don't leave the Pentax without the Li-Ion for a longer period it would be fine.
For my Pentax bodies I have always spare batteries, for my KP 3 of them, because I don't have the extra d bg batterygrip. With my K3 I had it, but I used it with larger and weighty lenses as well, the bg helped for a sensible balancing

[mroeder75]

I'd try it first with the Li-Ion. As soon as the clock-battery has enough charge and you don't leave the Pentax without the Li-Ion for a longer period it would be fine.
For my Pentax bodies I have always spare batteries, for my KP 3 of them, because I don't have the extra d bg batterygrip. With my K3 I had it, but I used it with larger and weighty lenses as well, the bg helped for a sensible balancing

Thanks. I have an extra battery, as well. In the 8-weeks or so after I received the camera, it always has had a battery in it, but it was not until I performed the above-described procedure that the camera remembered the time. I knew it was likely a problem with a watch type battery in the camera, but I did not know those tiny batteries were charged by the larger lithium battery until reading this thread. Thankfully, it seems like it will now hold a charge.

[photoptimist]

Date and time are important since I am an attorney. I want correct times and dates on my work photos, as you might understand. Since now it seems to work do you think I can get buy without a power supply for the clock battery? Or will my camera battery do the job from here?

Even if the little back-up battery inside the camera is working, the clocks inside of cameras are not the most accurate in the world. They depend on a quartz crystal time base that suffers from manufacturing tolerance and temperature sensitivity issues. Camera clocks will lose or gain seconds and even minutes over the months. Then there's the issue of forgetting to set or undo day-light savings time or change the time zone during travel.

If correct times and dates are crucial to you, you might make a habit of taking a photo of the displayed time and date on some more reliable time piece just before using the camera for work purposes and just after changing the battery.
Most smartphones can be set to automatically update their internal clocks from internet sources such that a snapshot of the phone's screen with a clock app running would provide nearest-second accuracy. The camera's timestamp on that photo will tell you the offset between the camera's clock and the true time.

Note: IANAL so I have no idea if camera photo timestamps have any evidentiary legal standing. In theory, it would be very easy for a fraud-perpetrating camera owner to adjust the camera's time and date before taking a photo (assuming they had access to the camera) and a more technically-skilled computer user could adjust timestamps after the fact(assuming they had access to the image file). But for purposes of documenting a timeline of work activities in a more trusting environment, what I've proposed will provide better accuracy by providing time estimates that are traceable to a reputable, accurate time signal.

[TimR]

I'd recommend the cheap external PS and leave it on for 24 hrs or longer.
A noname product is fine, such as this one:
HQRP AC Adapter for Pentax K-AC132 38780 K-3, K-5II, K-5IIs Power Supply Cord 884667419487 | eBay

It seems the internal MS414 battery is not completly depleted and has that leftover capacity that it can recharger over time.
So just never leave the K3 without its main battery for a long time!

I think 1,5 hrs are not quite long enough. But you don't want to risk depletion of your Pentax D-LI90 although I think if you set the K3 for

no Auto-Switch off it goes off before the battery is in danger.

@35mmfilmfan: Thats how I did it with my K3's and K5's as well and I liked the possibility to have AA's as well because in the Alps we had sometimes very low temperatures in winter (it changes though). AA's are that much more reliable then.
But the problem we are speaking here about is about the internal battery on the back of the mainboard, a tiny MS414 3V battery.

Photogem,
Thank You for the suggestion. I have just ordered one. I will try using it om my K-50 backup
Tim