Film-Tech Forum ARCHIVE: BR3032 battery for IMB RTC

This is topic BR3032 battery for IMB RTC in forum Digital Cinema Forum at Film-Tech Forum ARCHIVE.

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Posted by Marin Zorica (Member # 1716) on 02-25-2017, 05:44 PM:

You are all probably familiar with this type of battery for RTC od IMB board,m dolphin board etc.....

I went today to order some to have in stock and suprise than. Neither one big electronic components reseler has it on stock....liek farnell, rs components, tme.....also, farnell stated "no longer stocked"......

Since in US mouser and digikey has it, i went to check, and guys from Digikey told me, yes they have BR3032 in stock, but they cannot ship it outside of USA because of lithium restriction (i supposed it will be something like that) also, for mouser would probably go same way.

So, i could get it from Doremi (Dolby now), but if farnell or RS don't stock it, i suspect there will be problems in future.

What is replacement? I know CR3032 is SAME as BR3032, only is menione for higher current and due that is has much lower lifetime (even in datashet, lifetime is calculated for 20x higher current on CR type, don't know lifetime for CTR type for same current on BR type on test).

And for collegues in EU, except Dolby, where do you get them?

Posted by Carsten Kurz (Member # 5396) on 02-25-2017, 06:43 PM:

This must be a short-term supply problem.

https://www.reichelt.de/Knopfzellen-Lithium/BR-3032/3/index.html?ACTION=3&GROUPID=4241&ARTICLE=26707&OFFSET=16&

But if you have a service date and no BR available, I wouldn't hesitate to insert a CR3032 (from a good source).

- Carsten

Posted by Mark Gulbrandsen (Member # 72) on 02-25-2017, 08:32 PM:

I recently had an IMB fail just from changing that battery out. I also know of one other tech that has had that happen. It doesn't completely kill the board, but it won't boot up all the way. I recommend that you warn your customer this is a remote possibility before you do it, or you could be out 3K USD if he gets really pissed about it. My thinking is that on some boards the "supposed" super capacitor that retains the charge long enough to swap that battery out is not holding it's charge properly. Granted I have had only one board out of about 40 that I have changed the battery out fail on me... but none the less it is still a remote possibility.

And what about that battery right next to the one you can change out that is soldered in place? When does that need changing and who does it and how? Its is the same type of battery, except it's a solder in version and it's also not going to last for ever.

Mark

Posted by Carsten Kurz (Member # 5396) on 02-25-2017, 09:39 PM:

I am not sure which IMB you are referring to, but soldered-in cells typically are rechargeable cells that are only there to bridge the short time that's needed to swap the battery, similiar to supercaps. However, in order to do this, they must be charged prior to the battery change, so one needs to power the IMB for 30-60min prior to disassembly, and then swap the battery immediately. It's still a delicate process. Which media blocks offer clip/pin contacts to supply an external voltage to the circuit while the battery is changed? I have seen something like this on the Doremi IMB, but no documentation.
The IMS1000 has just a rechargeable cell soldered in, so it doesn't need to be changed, but has a total life expectancy of just 10 years - which may not be a big deal, since most IMS1000 will not survive more than a couple of years anyway - or was that months?

- Carsten

Posted by Marco Giustini (Member # 4544) on 02-26-2017, 03:30 AM:

I do like Dolby/USL's approach where you install a backup battery before swapping the main out. It takes all the panic away... [Frown]

Posted by Marin Zorica (Member # 1716) on 02-26-2017, 05:25 AM:

Carsteen, yes, last night i just ordered a bunch of BR both for IMB and ICP from that same shop.....i just hope they will not send me CR instead [Big Grin]

Anyhow, i also hear that after replacement IMB (doremi) was dead, this was probably due to bad support capacitor which shoudl take care of RTC and cert. for five minutes while exchanging battery. Also, accu batteries are not better solution, as they go away too. Something like old GORE board in series 1 which you should charge while stocked on shelf, but problem was you DO NOT know status of battery....so as time goes, a time between charging will be less since battery capacity falling off. In my opinion, best would be to have two same battery in paralell via simple diode to memory supply.....in that case you just swap one battery at time and will have no problem of drop out of power supply to maintain RTC and memory.

Posted by Carsten Kurz (Member # 5396) on 02-26-2017, 07:15 AM:

The Sony 510/515 have a twin battery setup in all three mission critical locations, plus, as far as I know, the Sonys do not estimate the batterie status, but actually measure the voltage to report it. I think the CAT745 does the same (but there was a bug in that function for a long time).

BTW - the Sony manuals state CR replacement types explicitly.

A function/procedure to insert your own transitional backup supply for the change as USL uses it is indeed very helpful and doesn't expose the on-location service technician to unexpected disasters.

I think it's ridiculous we have to discuss simple battery changes on a technical forum. But if media blocks go brain-dead and need to be sent away for weeks for rehab, even if you follow the manufacturer procedures...

- Carsten

Posted by Steve Guttag (Member # 268) on 02-26-2017, 08:25 AM:

The soldered in battery on the IMB is supposed to be the certificate battery (I believe it is the Christie bulletin that describes it).

While on the battery subject, GDC issued a technical notification that the batteries on their 2000AR and 3000 IMBs need to be changed semi-regularly and there are multiples of them on the IMBs. Furthermore, there are two generations of battery styles so you need to change with the right one. One is to contact GDC to obtain the right parts via serial number. If the server is within warranty/extended warranty, then the batteries are covered.

Posted by Harold Hallikainen (Member # 5405) on 02-26-2017, 09:46 AM:

As mentioned earlier, it is something that we have a large discussion on battery replacement. I've been part of a large discussion on batteries recently. As mentioned earlier, the battery in an IMB holds up the private key and RTC. Loss of the battery deletes the key. Recent calculations based on measured battery current (13 uA) in a media block showed the battery should last 7 years if the media block was never powered and 14 years if it was powered 14 hours per day. One area of concern, though, is contact fritting. With the extremely low current through battery holder contacts, minor corrosion is not "burned away" due to the current through the contact. Special contact material or fritting lubricants can minimize the issue. Another solution is to solder in the battery, but that makes field replacement difficult to impossible.

IMBs are very complicated, but sometimes it the simple battery holder that causes issues.

Harold

Posted by Steve Guttag (Member # 268) on 02-26-2017, 11:47 AM:

On my post above about the soldered in battery...I meant to type ICP (no IMB). Again, I'm not sure which of the DLP OEMs identified the soldered in battery as the certificate battery. If I find the document again, I'll post which it is.

Posted by Mark Gulbrandsen (Member # 72) on 02-26-2017, 12:10 PM:

Yes, just tracing which chips the batteries feed makes it easy to determine what each battery does. The MAXQ1103 chip is an interesting one which is powered by the solder in battery is a multi layer type high security chip/CPU.

https://www.maximintegrated.com/en/products/digital/microcontrollers/MAXQ1103.html

The DS3232 is an RTC clock chip with integrated crystal time base.

https://datasheets.maximintegrated.com/en/ds/DS3232.pdf

One has to assume the solder in battery has to be replaced at the factory, because the only way it's going to be safely done without losing certs is by powering up the board itself or supplying battery power across the existing battery. This battery may well determine the actual life span of the equipment it is used in unless they come up with a way to reload the certs.

As for the GDC batteries, never remove both of them at the same time or you WILL lose the certs on the media block. The pair of batteries is in parallel and you replace one battery at a time.

Mark

Posted by Dave Macaulay (Member # 813) on 02-26-2017, 03:49 PM:

The board shown is an ICP, and the original question was about an IMB.
The ICP removable battery only powers the ICP RTC, and even without that battery most projectors will still work OK (with some oddness). The soldered in one protects the certs... I have had no good answer as to its life or what happens when this battery dies... can it be replaced and the board loaded with new certs or is it dead like an expired LD?
For the Doremi IMB, I haven't had a failure and have replaced a lot of the batteries. You do have to be very careful: read and follow the battery change instruction sheet! I think there's even a battery change kit available with a plastic spudger and a plastic sleeve to slide over the top contact arm, ensuring that it can't touch the bottom contact.