4.5V Battery Replacement for Early Compact Macs?

[68kPlus]

(Uploaded to Tinker Different as well)

Hi everyone,

Looking to find a way to replace the expensive, hard to find 4.5v battery for the Macintosh Plus in particular. The closest replacement is the Exell PX21, which costs around $50 AUD here in Australia, and the cheapest is the Unicell A133 4.5V which is $45.
There are some German adapters that are also expensive that convert 3x LR44 to the PX21, but I can't seem to find them cheap.

Any ideas?

 

[cheesestraws]

I can't remember exactly what I did, but my replacements were several coin cell type cells in a heatshrink tube, before I stopped bothering with batteries at all . But there is (or at least was, a few years ago) a coin cell which when stacked added up to both the right height and the right voltage.

This isn't particularly helpful, I appreciate, but might be a pointer in the right direction.

 

[MindWalker]

I know this is not a mechanically good solution (nor does it last as well as the original battery), but I designed and used this 3D-printable in my Mac Plus: https://www.thingiverse.com/thing:4558846

 

[68kPlus]

Thanks for the help! Just need a 3D printer now...

 

[68kPlus]

I can't remember exactly what I did, but my replacements were several coin cell type cells in a heatshrink tube, before I stopped bothering with batteries at all . But there is (or at least was, a few years ago) a coin cell which when stacked added up to both the right height and the right voltage.

This isn't particularly helpful, I appreciate, but might be a pointer in the right direction.

The only reason I want a battery is because the mouse speed is slow each startup, and the date is wrong (2020patch fixes this, but you still need a battery)

 

[Byrd]

Thanks for the help! Just need a 3D printer now...

I can run some of these off for you mate if you pay shipping - I'm in Melbourne. Looks like a good design, never seen these.

 

[cheesestraws]

The only reason I want a battery is because the mouse speed is slow each startup, and the date is wrong (2020patch fixes this, but you still need a battery)

Yeah, I'm not saying that everyone else should do what I'm doing, only why my knowledge isn't up to date.

 

[68kPlus]

I can run some of these off for you mate if you pay shipping - I'm in Melbourne. Looks like a good design, never seen these.

That would be great, only before we can work something out I'll see if I can source some wire and the contact plate stuff.
Thank you!

 

[desertrout]

I've had long-term success with ER14505 batteries, which are pretty easy to get in my experience

 

[tedward]

I can't remember exactly what I did, but my replacements were several coin cell type cells in a heatshrink tube, before I stopped bothering with batteries at all . But there is (or at least was, a few years ago) a coin cell which when stacked added up to both the right height and the right voltage.

This isn't particularly helpful, I appreciate, but might be a pointer in the right direction.

I know it's been about a year so, sorry for resurrecting this old thread but I've been recently hunting down this very thing and found the answer.

According to Wikipedia

[523 is most commonly] Used in cameras and Apple Macintosh computers (such as the 128K through 512K and similar). As the IEC name suggests, this is often just 3 LR50 batteries stacked together.

So, the three batteries you were thinking of were the LR50 which you can still get on Amazon for about $4 $1 each.

Correction: They're only about $1/cell, not $4.

 

[cheesestraws]

So, the three batteries you were thinking of were the LR50 which you can still get on Amazon for about $4 each.

Well found! Thankyou for updating the thread.

 

[RedJacketPress]

I enjoy an elaborate solution as much as the next person — but if you just want to solve the problem, rather than spend time solving the problem, Amazon has ER14505 batteries for around $10-$15 each (as I discovered recently when I wanted one for a 512K Mac).

 

[3lectr1cPPC]

They're lithium too! Will last a lot longer before leaking than an Alkaline original would. Specifically, Li-SOCL2, which I believe is the same type that the 1/2AA batteries are. So, still don't trust one to last longer than 15-20 years before they burst. Better than the "could be whenever" attitude that a lot of Alkaline batteries seem to have at least...

 

[s_pupp]

I’ve been lucky. My first (Energizer) lasted 17 years before it died, and the second (Exell A21PX) lasted ten years before I removed it from my Mac Plus out of concern for the potential for leaking, still working. Neither has leaked. The Exell is still selling on Amazon.

 

[68kPlus]

I ended up using a 1.5V AA battery which somehow is still keeping the settings I needed (mouse speed and a few others). Clock has fallen about 2-3 weeks behind though.

 

[MichaelLAX]

I enjoy an elaborate solution as much as the next person — but if you just want to solve the problem, rather than spend time solving the problem, Amazon has ER14505 batteries for around $10-$15 each (as I discovered recently when I wanted one for a 512K Mac).

Aren't these AA sized and we need 1/2-AA sized; or am I confused?

 

[RedJacketPress]

ER14505 seem just slightly larger than AA, if I recall correctly. They're installed in a port on the Analog Board (accessible through the back of the computer), rather than on the Logic Board.

 

[68kPlus]

Update: still holding a charge since October 2022, and the mouse speed and memory cache setting is still holding.
At least it works for my purposes!

 

[ymk]

It's common for modern Alkalines to explode and leak in short order.

I've stopped putting them in anything I care about.

 

[3lectr1cPPC]

Funny enough, the longest "lasting" (not in charge, but in not leaking) Alkalines that I've had over the years have never been from the most known brands. The Duracells and Energizers all blow, but the random "New Leader" battery still remains intact.