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tsialex

Contributor
Jun 13, 2016
13,459
13,608
Is there any way to tell whether the BT2032 battery is ending its lifecycle?
End of life point is depends on the application, generally below 2,7V. You should replace it around 2.9V, since it will rapidly decrease after that.

What are the failures caused by it?
In a MP4,1/5,1/6,1, battery basically just keeps the internal clock and the time from boot. When the battery fails, time from boot stops to increase or could have weird values stored, like negative values, this causes problems with macOS leading to KPs and can cause sleep to crash in a way that you will need to power off your Mac Pro.
 

iluvmacs99

macrumors 6502a
Apr 9, 2019
920
673
End of life point is depends on the application, generally below 2,7V. You should replace it around 2.9V, since it will rapidly decrease after that.


In a MP4,1/5,1/6,1, battery basically just keeps the internal clock and the time from boot. When the battery fails, time from boot stops to increase or could have weird values stored, like negative values, this causes problems with macOS leading to KPs and can cause sleep to crash in a way that you will need to power off your Mac Pro.

Where is a good source in obtaining the BR2032? I find it difficult to source one as opposed to the CR2032 which is plentiful. Also can the CR2032 be used as a replacement for the BR2032?
 

JoeInMilwaukee

macrumors regular
Apr 7, 2015
207
239
Milwaukee, WI
Where is a good source in obtaining the BR2032? I find it difficult to source one as opposed to the CR2032 which is plentiful. Also can the CR2032 be used as a replacement for the BR2032?

Both batteries are the same physical size and output the same voltage. My understanding is that the CR2032 is optimized for high-current, short-duration loads (for example, a garage door remote transmitter) whereas the BR2032 is optimized for low-current, long-duration loads (for example, memory backup).

You can use a CR2032 in place of the BR2032 but it most likely won't last as long as the BR2032.

When I replaced the BR2032 in my Mac mini, I went with a BR2032 from Digi-Key:

https://www.digikey.com/products/en...000&quantity=&ColumnSort=0&page=1&pageSize=25
 
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haralds

macrumors 68030
Original poster
Jan 3, 2014
2,994
1,259
Silicon Valley, CA
I just replaced mine. Probably was fine, but was 7+ years old. Have been struggling off and on with PCIE eSata enumeration issues, but this battery likely has no impact on that.
 

tsialex

Contributor
Jun 13, 2016
13,459
13,608
Both batteries are the same physical size and output the same voltage. My understanding is that the CR2032 is optimized for high-current, short-duration loads (for example, a garage door remote transmitter) whereas the BR2032 is optimized for low-current, long-duration loads (for example, memory backup).

You can use a CR2032 in place of the BR2032 but it most likely won't last as long as the BR2032.

When I replaced the BR2032 in my Mac mini, I went with a BR2032 from Digi-Key:

https://www.digikey.com/products/en/battery-products/batteries-non-rechargeable-primary/90?k=&pkeyword=&sv=0&pv46=7536&pv258=79&sf=0&FV=ffe0005a,ffec4d28,1f140000&quantity=&ColumnSort=0&page=1&pageSize=25
Another difference between BR2032 and CR2032 is the chemistry tolerance for high temperatures of BR2032, BR2032 is rated for 80ºC wile most CR2032 are rated for only 60ºC.

Panasonic BR2032:
Screen Shot 2019-07-28 at 16.26.34.png


Panasonic CR2032:
Screen Shot 2019-07-28 at 16.29.09.png


This is important for a Mac Pro or a Mac mini, since both are located in high temperature areas. A CR2032 in a Mac mini will fail in less than a year.
 

haralds

macrumors 68030
Original poster
Jan 3, 2014
2,994
1,259
Silicon Valley, CA
Another difference between BR2032 and CR2032 is the chemistry tolerance for high temperatures of BR2032, BR2032 is rated for 80ºC wile most CR2032 are rated for only 60ºC.

Panasonic BR2032:
View attachment 850250

Panasonic CR2032:
View attachment 850252

This is important for a Mac Pro or a Mac mini, since both are located in high temperature areas. A CR2032 in a Mac mini will fail in less than a year.
Yup. Looked that up. The battery have a don't use after 2025, so plenty of time for now.
 

thibsweb

macrumors newbie
May 5, 2003
18
14
While doing some macpro spring cleaning, I just replaced the BR2032 in my MacPro 2009, bought in early 2009. I thought 13 years of service was a good enough amount of time to give the CmP a new Panasonic BR2032 battery. I tested the old battery after removing it and it rated at 2,85V. Pretty damn nice for a 13 year old battery ! But still, it was time for a retirement :) Now I am good to go for the next 15 years or so.
 

Michael.S

macrumors regular
Jul 30, 2014
102
65
Could a faulty battery cause this message - see attached picture - on an MacPro 5.1?

Or could this be related to any issue on the connected 30" Cinema Display?
 

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tsialex

Contributor
Jun 13, 2016
13,459
13,608
Could a faulty battery cause this message - see attached picture - on an MacPro 5.1?

Or could this be related to any issue on the connected 30" Cinema Display?
When the RTC battery is below 2.9V a lot of crazy things start to happen, but I never got this exact one.

Anyway, you should check the BR2032 battery with a voltmeter/multimeter and replace it whenever below 3.00V.
 

mckyvlle

macrumors 6502a
Nov 21, 2007
575
5
London, UK
Think of it another way, a 5.1 is about 10 years old now and replacing that battery is just cheap maintenance.

I replaced mine about year ago, and the spurious hang during boot went away. Before the battery replacement, I would constantly need to hold Opt during boot and select my boot drive!
 
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