Rayovac 4.5 battery replacement hack

[Fizzbinn]

I’ve previously used a 3 AAA battery holder to replace the dead Rayovac 4.5v “Computer Clock Battery” in a couple of my Macs.

After some chat discussions I thought I’d try something different for my Performa 575, especially after noticing that in the Macintosh LC 520/550/575 Service Source doc it notes that 575 battery is good if it’s 3 volts or higher, the same as it says for the 520 & 550 which use 1/2 AA 3.6v batteries…

So why not try a CR2032!

I though of cannibalizing a @Geekybit MeowToast 1/2 AA battery Replacement (which are awesome) but found another holder on Amazon so I can keep those for Macs with the 1/2 AA holder.

AuBreey 5PCS/LOT for Arduino Lilypad Coin Cell Battery Holder CR2032 Battery Mount Module:

Amazon.com: AuBreey 5PCS/LOT for Arduino Lilypad Coin Cell Battery Holder CR2032 Battery Mount Module : Electronics

Amazon.com: AuBreey 5PCS/LOT for Arduino Lilypad Coin Cell Battery Holder CR2032 Battery Mount Module : Electronics

www.amazon.com

Cracked open the Rayovac mainly since I was curious:


Soldered the cable from the old battery to the new holder:


Reused the velco from the old battery too (still had stickum):


575 board with 3 AAA based battery holder:


575 board with CR2032 based battery holder:


Close up pic, perhaps most importantly it works just fine!

 

[TimHD]

Nice. Will try this trick too.

 

[mmu_man]

Ah yes I remember breaking into the same one some years ago… With patience and a good cutter. I think the coin cell might actually fit the original case even.

 

[The Salami Boss]

Hah, I replaced mine with the 3-AA holder built in to some Wal-Mart LED string lights. Just flip pop in some lithiums, flip the switch to 'On', and tape it there.

 

[Geekybit]

Just so you know I am currently working on a 4.5v Battery pack option...

 

[jessenator]

3 volts or higher

I wonder if this is the same (mostly) across the board (I know some II-series have multiple batteries…). I've been using a 3x button cell holder (which was a terrible 3d-print object, but some heat made it work), but I've been told even those alkalines will leak.

I have some of the meowtoast adapters and would like to just use them. So if any Mac can take at least a 3V cell, do we need a 4.5V 1:1 replacement? I'm sure this question has been asked, but I can't, for the life of me, recall when/where/if it was answered.

 

[Fizzbinn]

Just so you know I am currently working on a 4.5v Battery pack option...

So if any Mac can take at least a 3V cell, do we need a 4.5V 1:1 replacement? I'm sure this question has been asked, but I can't, for the life of me, recall when/where/if it was answered.

I'm wondering the same thing. The fact that all the Apple Service source docs I've checked for Mac's with these 4.5V batteries say the same thing as those with (single) 3.6V 1/2 AA batteries, "If the battery voltage is below 3.0 V, replace the battery" makes me think that maybe the logic board requirements didn't change just the battery tech to do it.




Something like the Apple requirement is a battery that degrades to under 3V in 10 years (or some other time period that doesn't really matter for the sake of this argument).
- A lithium based 1/2 AA battery with new production voltage of 3.6V degrades to under 3V in 10 years
- But it takes an Alkaline battery with a higher new production voltage of 4.5V to degrade to under 3V in 10 years
To make the change I'm guessing the Alkaline Rayovac solution must have been cheaper or otherwise beneficial to Apple in some way.

Just a guess...

 

[Geekybit]

The version I was going to go with was going to be a 3 1.5v button batteries since they are not rechargeable and will not back charge. Then a 3d printed case with the lead attached ... but seeing how it works the same as the standard Mac boards, yeah I could make a simple Meow toast version...

Keep in mind the circuit for the batteries are designed to run from a battery which means they actually have a fairly large tolerance of voltage range...

from what I understand the Mac boards don't start acting weird till 2.4-2.6v for the battery though the manual says 3.0V ... also CR 2032 say they are 3v but most actually are 3.2v out of the gate

 

[Fizzbinn]

The version I was going to go with was going to be a 3 1.5v button batteries since they are not rechargeable and will not back charge. Then a 3d printed case with the lead attached ... but seeing how it works the same as the standard Mac boards, yeah I could make a simple Meow toast version...

Keep in mind the circuit for the batteries are designed to run from a battery which means they actually have a fairly large tolerance of voltage range...

from what I understand the Mac boards don't start acting weird till 2.4-2.6v for the battery though the manual says 3.0V ... also CR 2032 say they are 3v but most actually are 3.2v out of the gate

I was trying to find some more backing on the ever truthful internet for the idea that alkaline batteries (like the Rayovac) lose voltage faster than regular, non-rechargeable, lithium batteries (like 1/2 AA and CR3032) and found this:

boat-project.com - boat project Resources and Information.

boat-project.com is your first and best source for all of the information you’re looking for. From general topics to more of what you would expect to find here, boat-project.com has it all. We hope you find what you are searching for!

www.boat-project.com

Sounds legit?

Also somewhere I think I read that there are Color Classic logic boards that have the connector for the Rayovac battery instead of the 1/2 AA battery holder. Anyone recall this too?

A Meow toast board with through hole solder points for a donated Rayovac battery connector seems like it could potentially serve both use cases (Soldering wires to surface pads as I did above is slightly annoying). Just my 2 cents.

 

[Geekybit]

I was trying to find some more backing on the ever truthful internet for the idea that alkaline batteries (like the Rayovac) lose voltage faster than regular, non-rechargeable, lithium batteries (like 1/2 AA and CR3032) and found this:

boat-project.com - boat project Resources and Information.

boat-project.com is your first and best source for all of the information you’re looking for. From general topics to more of what you would expect to find here, boat-project.com has it all. We hope you find what you are searching for!

www.boat-project.com

Sounds legit?

Also somewhere I think I read that there are Color Classic logic boards that have the connector for the Rayovac battery instead of the 1/2 AA battery holder. Anyone recall this too?

A Meow toast board with through hole solder points for a donated Rayovac battery connector seems like it could potentially serve both use cases (Soldering wires to surface pads as I did above is slightly annoying). Just my 2 cents.

This is what I was thinking of sell a meow toast with a two through holes... and a bit of Velcro tape and the wires and connector since they still sell them to this day and they are cheap.

 

[kahlil88]

View attachment 37244

Just got a 3×1.5v button cell holder from Mouser to replace the Rayovac battery but... am I losing my mind or is this diagram telling me black is positive and red is negative?

 

[kahlil88]

Wanted to share my very cheap solution: LR44H button cell holder (batteries included) for $3.50 (99 cents + shipping) from Mouser and I used a cable tie to hold it down.

 

[reddrag0n]

Wanted to share my very cheap solution: LR44H button cell holder (batteries included) for $3.50 (99 cents + shipping) from Mouser and I used a cable tie to hold it down.

i ordered some of those and i am about to make one of those for my performa 637cd

 

[reddrag0n]

this is the battery holder in the install process


one thing i noticed is that the batteries i got even though they say 1.5v, they are over 2v from the packaging.


2 batteries show almost 5v


all 3 batteries show over 7v


is mine going to blow up my computer?

 

[MindWalker]

You might want to replace the battery in your multimeter (battery symbol on-screen), it's not uncommon for a multimeter to measure high when it's running on low-battery (reference voltage too low)

Been there myself...

 

[François]

I replaced a Rayovac with a CR2032 by soldering directly to it, no need for a support!

My method in pictures:

 

[Fizzbinn]

I replaced a Rayovac with a CR2032 by soldering directly to it, no need for a support!

My method in pictures:
View attachment 57432 View attachment 57433View attachment 57434View attachment 57435View attachment 57436

That works! (Looks nice with the heat shrink wrap too)

 

[pizzigri]

Also somewhere I think I read that there are Color Classic logic boards that have the connector for the Rayovac battery instead of the 1/2 AA battery holder. Anyone recall this too?

i used to own a color classic II like 20 years ago, and the board (which was the same as the LC550) used the 4.5v battery

 

[KnobsNSwitches]

I did this last night (with the amazon battery holder), works like a charm. Thanks much for the idea!

 

[alectrona6400]

dont wanna necro a thread but i just did this with my 6400, works great. soldered a cr2032 battery holder to the wires so i can replace it whenever i need to.