Macintosh 128k~Plus PRAM Battery in 2020: EN133A/523

[JDW]

I need to replace a couple PRAM batteries in my 512k machines.  Have any of you made a purchase recently?

I see this EN133A/523 on Amazon for $6.60 + $1.99 shipping.  You will also find an "Excell" brand for a higher price.  To me, even $6.60+$1.99 is rather expensive.  I'm curious if there's a quality difference.  Most likely they are both made in China, but even in China the quality can vary.

Thanks.

 

[Crutch]

I’ve used the Excell batteries in several old Macs. As far as I can tell they work perfectly. Excell batteries are made by a company called Batteries In A Flash, which claims on their website and amazon store to make these batteries in the USA.  https://www.exellbattery.com/

 

[ktkm]

I have used Excell none-stop in my Plus for six years now. I cut down on the shipment by ordering three at the time. I store them in the fridge.

 

[LaPorta]

I purchased a non-descript one a year or so ago off of amazon. It appears to work just fine with no issues at all.

 

[MOS8_030]

I got a couple of these Exell Battery A21PX 4.5-Volt Alkaline Battery from Amazon a couple of years ago.

I notice the price has increased since then.

 

[jessenator]

This sounds like a perfect project for a 3D-printed substitute. This is all shooting from the hip, and might be covered elsewhere, so I apologize if I'm off base.

I'm thinking the nice, tubular battery holder (a la HarborFreight flashlight) is too wide for this application, with its 3x AAA 1.5V cells. I wonder if an adequately spaced , 3d-printed sabot could be made to hold AAAA or something like the 9V innards' cells:

Another thought was to use button cells as well, like the LR1130, which are priced about 20 for $5 (just shy of 7-full-batteries-worth)

I know this has probably been talked about as well elsewhere. I'm approaching it from an availability standpoint rather than sheer price. Some of those button cells might be made for longer than the A21PX cell. Don't know about the draw of one of those A21PX cells, vs something like 3x LR button cells, but I can't imagine it would be terribly intense.

Edit: I had a terrible thought that the diameters might exclude the LR1130 as a possibility, but it's only .457" while the A21PX is .66"— the only tricky parts would be wiring up an contact extension.

 

[JDW]

Thank you for the feedback.

Seems like all of you use the expensive Excell version.  I was actually hoping someone in our midst had experience with the lower cost (but by no means "cheap) A21PX version.  When buying multiple batteries, especially when shipping outside the USA, price matters!

 

[Insanely Digital]

Old post, I know, but I just order a few of these to try out...
https://www.ebay.com/itm/203783537098

 

[falen5]

recently saw one of these fitted to an se/30 i was working on

MacBatt CR2032 PRAM Lithium battery replacement for Apple Macintosh computers | eBay

MacBatt CR2032 PRAM Lithium battery replacement for Apple Macintosh computers | Computers/Tablets & Networking, Computer Components & Parts, Computer Cases & Accessories | eBay!

www.ebay.ie

id imagine you would have to slice off some of the sides to get it to fit into the battery slot of a 128 to a Plus

but at least you wouldnt have to ever worry about acid leaks again

 

[Insanely Digital]

recently saw one of these fitted to an se/30 i was working on

MacBatt CR2032 PRAM Lithium battery replacement for Apple Macintosh computers | eBay

MacBatt CR2032 PRAM Lithium battery replacement for Apple Macintosh computers | Computers/Tablets & Networking, Computer Components & Parts, Computer Cases & Accessories | eBay!

www.ebay.ie

id imagine you would have to slice off some of the sides to get it to fit into the battery slot of a 128 to a Plus

but at least you wouldnt have to ever worry about acid leaks again

I use these wherever I can (not in a 128K/512K/Plus!) They are excellent. They fit perfectly into the 1/2 AA battery holder.

 

[finkmac]

i just desolder the 1/2 AA holder and solder in a cr2032 holder. works out cheaper

 

[Insanely Digital]

i just desolder the 1/2 AA holder and solder in a cr2032 holder. works out cheaper

Yep, that'll work. I like to preserve the original look of the boards. That's just me.

 

[dv-]

I was under the impression that the 3.6v stuff didn’t work on the Plus, which requires 4.5v?

 

[falen5]

I was under the impression that the 3.6v stuff didn’t work on the Plus, which requires 4.5v?

Good to know DV - I have a simple rule for 68K macs ........... no battery - i have seen so many destroyed from acid - for what i do on a mac i dont need the battery - i dont care about the date and time , i have a watch on my hand !!!, mouse speed , blink speed , click speed............ jasus who cares ..... maybe there is some software that people use that requires a battery ........... i just love the sight of a clean , undamaged , EMPTY battery holder ...... every time I see one I feel better , for the machine

 

[nathall]

I was under the impression that the 3.6v stuff didn’t work on the Plus, which requires 4.5v?

3.6v will work fine. The original spec was 4.5v but I’ve been using 3.6v in my originals forever. I have not ever been able to ascertain a difference between using one vs. the other. Clocks still keep perfect time and all settings remain even when the machine sits unpluged for a while.

 

[dv-]

3.6v will work fine. The original spec was 4.5v but I’ve been using 3.6v in my originals forever. I have not ever been able to ascertain a difference between using one vs. the other. Clocks still keep perfect time and all settings remain even when the machine sits unpluged for a while.

Ah, interesting. Thank you for the info!

 

[Insanely Digital]

Old post, I know, but I just order a few of these to try out...
https://www.ebay.com/itm/203783537098

Yep, fits perfectly in the 512K battery compartment! Fresh LR44 batteries currently measuring 4.6 volts.

 

[Insanely Digital]

Here's a picture.

 

[KMM]

Here's a picture.View attachment 79419

Where can I get the holder?
Thanks.

 

[shirsch]

Why not do it this way? The LR501 battery has more capacity and three of them fit without an adapter. The Excel battery is simply (3) LR501 with spot-welded strips between them.