I’m concerned about putting a non-rechargeable battery in a circuit that was designed to recharge. At least iFIXIT specified a rechargeable. The non-rechargeable batteries have dire warnings about trying to recharge them.
Can you share the link mentioned previously on iFixit? I don’t recall any PRAM battery in any of my desktop Mac’s as being rechargeable.
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This iFIXIT page iMac G4 17 800 MHz EMC 1936 PRAM Battery Replacement - iFixit Repair Guide linked to this Amazon page https://www.amazon.com/ER14250-LS14250-ER14250H-Household-Batteries/dp/B00XBMEHOO/ref=pd_sim_121_5?_encoding=UTF8&pd_rd_i=B00XBMEHOO&pd_rd_r=NJNZSRVSD3EDXF97P11P&pd_rd_w=RO6k6&pd_rd_wg=FO9d3&psc=1&refRID=NJNZSRVSD3EDXF97P11P&tag=ifixitam-20
That’s one of the ones I found searching but there is no mention of the battery being rechargeable unless I missed it. The battery looks like the same one used in many desktops including the old fruit flavored CRT ones and those are definitely not rechargeable.
EDIT: A description:
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The iFixit repair guide you linked was user-contributed, so it’s not necessarily vetted in any real way. iFixit is great, and I’ve used it many times, but there is wide variability in the quality of its user-contributed guides. It’s true that it links to an Amazon page that says it’s for a rechargeable battery, but I wouldn’t necessarily trust its accuracy.
In any case, I have a service manual for that model of Mac, and it specifies Apple part # 922-4760 for the battery, which is a basic, non-rechargeable 1/2 AA 3.6V lithium battery.
Interestingly, the service manual takes pains to mention in several places that you should apply thermal paste to the heat pipes (thick metal connectors between the base plate and the top of the unit) if you take it apart. Even though the model has a fan, it relies on passive cooling to maintain operating temperature.
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Is there an Apple web page that lists that part?
The ER14250 battery type is Lithium Thionyl Chloride NON-rechargeable.
The Amazon ad is incorrect.
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Excluding Apple’s unreliable support forums, I don’t see anything on their public site. It’s the correct Apple part number, though, and it’s a common one. It appears in quite a few Apple service manuals, but it actually refers to a commodity part. When the service manuals include photos, several different third-party 1/2 AA battery brands are used as “Apple” 922-4760 batteries. In my own experience, I’ve seen the purple-and-green “Tadiran” brand most often as original “Apple” batteries, but I have seen others.
I also note that the service manual says nothing about rechargeable circuits or batteries, despite having lots of warnings about other things, like the thermal pipes.
I appreciate being cautious with vintage equipment, but this battery is not an exotic part. If you are very concerned about it, open the case on your iMac and get the specific brand and part number.
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I see now but my point is that type of battery has never been rechargeable in my experience and I don’t know of any desktop computer that would have a rechargeable circuit as opposed to a laptop. Any seller can put out information that is not necessarily correct. I gave the link to one that OWC has that should be correct as the models page indicates.
And of countless ER14250 batteries on Amazon some are listed as rechargeable and some as definitely not.
You can search Apple’s site to exhaustion and never find “Apple part # 922-4760”
(or any other part number) but if you Google it, you find this:
No way in hell, is that what goes in my 15" iMac G4.
I had really hoped to be sure that the battery I had in hand when I cracked that case was the right one, because of all times RIGHT NOW is a VERY BAD time for me to have the guts of a computer spread out in a room for a week or two or… :-{
But to me, it looks like a crap shoot. Thanks for all your advice, sincerely. No thanks to Apple.
I’ll let you all know when I do crack the case.
As stated already, Amazon is not an accurate source of information and you provided further evidence with that post.
One site that has a lot of information is Everymac.com and this page indicates the same 3.6v Lithium battery that has mentioned by myself and others in this thread:
The 3.6v half AA is a standard in PRAM batteries as well as the 2032 and 2025 3v coin batteries found in some of the older Mac Minis.
Lithium batteries generally do not leak. Alkaline batteries, on the other hand, leak with a vengeance.
Well, the PRAM battery is definitely dead. You’re right that iFixit doesn’t identify the battery.
According to MacTracker, all of the iMac G4 models use a 3.6v Lithium battery, type 922-4760. This appears to be an Apple part number, but if I do a web search for it, I find a few sites selling it for between $7 and $15.
This looks like a “1/2 AA” size battery, but I haven’t been able to find proof of that (e.g. a photo of the battery showing its size markings), so I can’t recommend going that route unless you’re prepared to possibly buy a battery that won’t fit.
There are two types of the 2032 and 2025 batteries: the BR and CR series. I believe Apple uses BR-series batteries in its computers; I have BR2032 batteries in my MacPro.
From the article:
When I replaced some older Mac Mini batteries, they were the CR type and seemed to be original but hard to say for sure. These would be models from around 2005-2007.
When I had to replace the 3.6 half AA ones in various computers, I recall only one type for those as they were/are fairly common and usually were the purple ones:
EDIT: One thing I noticed about the chart provided is that the testing was done at 80 Celsius (176 Fahrenheit) which is pretty extreme in regard to computers so I don’t know how much longer the BR would last in normal, non-extreme conditions.
Some models did use alkaline such as the 128K, 512K, Mac Plus as well as a Performa 6400 which I still own and use.
This article mentions the Mac Plus:
Mine uses the 4.5v one in this link but I later replaced it with a battery case using lithiums:
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Well, I can’t deny you all the pleasure of watching me eat this breakfast plate of steaming crow… ;-}
Before I cracked my iMac, I did pickup a “non-rechargeable” battery at the local Batteries + so I would be covered either way. And yes, the iMac battery was not rechargeable, but it was replaced with no difficulty.
And to add insult to injury, the batteries whose Amazon page clearly stated were rechargeable…less clearly said in the fine print on the cells that they were not.
Thank you all for your advice. Next time who am I going to trust, Amazon, iFIXIT or TidBits? Duh… ;~}
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Glad to hear that it worked out in the end. We all have to be careful as to the source of information out there and it’s hard to tell sometimes. Often those local stores are a good bet as long as they take returns if it’s the wrong part.