Replacing the Lithium battery in a Macintosh 9500


Compatible replacement batteries
for the Mac 9500 series
BrandPart NumberCapacity
TADIRAN TL-2150  0.95  3.6
TADIRAN TL-5902  1.20  3.6
TADIRAN TL-5101  0.95  3.6
TADIRAN TL-5151  0.70  3.6
 other?  ?  ?  ?

Other information, datasheets, sources
Battery maker
Battery maker
A very useful site with lots of info and
links for various Mac models
An excellent source of all things Mac
in New York City


The PRAM lithium battery is located near the top right-hand-side at the front of the computer. The holder for the battery is on the motherboard facing the CDROM drive (or whatever you have installed on the top of the chassis.)  

The picture to the right and the one below show the little hooks on the battery holder lid. You will need to get these hooks disengaged from the base of the battery holder in order to be able to remove the lid and then the battery. Hopefully, these two photographs help you identify the location and function of the hooks.

I used my trusty pen-knife to gently disengage the lid hook from the end of holder nearest the front of the computer.

As the lid is moved you should be holding onto it with a finger etc. or it will fall down the face of the motherboard. An alternative would be to lie the computer on its side to remove the battery holder lid - whatever works for you.

Once the front-end hook is disengaged you gently work the lid "up" from the front end. The lid should pivot somewhat around the rear hook - just don't force it too far. When the front end of the lid has moved a little you can use a small screwdriver to push the lid from the other, rear, end of the battery holder. You're trying to push the lid rear-wards to disengage the rear hook from the base of the holder. You cannot push very far due to other components on the motherboard but you only need a millimetre or so to disengage the hook. Obviously if you are using a knife or other sharp or pointed object you need to be very careful not to damage the motherboard or any other parts.

With the battery holder lid out of the way, you can now remove the battery itself. While I believe that the battery holder's orientation is the same direction in all 9500 series Macs, make certain you know which way round the battery is before you remove it. This is just a good habit to get into. There is nothing worse that getting something entirely taken apart only to realize that you don't know the orientation of some critical component. You should verify the orientation of the battery before you remove it. If you can't see a marking on the battery then use something like a felt-tip pen to make a mark on the battery to remind you which end goes where.

That said, I use a small screwdriver to pry the battery out of the holder and a finger to try to prevent the battery from going astray.

Again, you could try putting the computer onto its side. The method I describe here has worked quite well for me; there are undoubtedly other methods that would be as straightforward. Of course, you could also remove the motherboard per the service manual...

The negative (-) terminal of the battery faces the front of the computer while the positive (+) terminal faces the rear of the computer as shown in the picture below. The magnified view in the upper right of the picture has a yellow + and - added to the photo but the battery holder base itself has an icon indicating polarity molded into the plastic.

Once you have the battery out inspect its terminals. They should be clean and free of any dirt/corrosion/etc. If not, be certain to clean the terminals in the battery holder itself. I have not personally ever seen a corroded lithium battery.

You can check the battery with a battery checker or a voltmeter. This kind of battery tends to hold its voltage until it is almost exhausted. Anything below about 3.25 volts as a minimum indicates that the battery in question is finished. These batteries are not rechargeable.

The table at the top of this page should help you in finding a suitable replacement battery. The TADIRAN 0.95Ah battery listed at the top of the table was the original battery in the 9500s I've looked at. There are, I believe, now batteries available with a higher capacity. The real killer of these batteries however is unplugging your Mac. The 9500s are drawing a fair bit of power even when turned off. If you unplug them or switch off the power-bar, the computer just draws what it needs from these batteries. If you were going to be storing your Mac for a long period it might make some sense to remove the battery altogether for the duration.

Reinstalling a battery is essentially following all of the previous steps in reverse. Obviously you want to pay attention to which way round you install the battery in the holder...

The battery can be replaced without removing the motherboard if you are patient and careful. Removing the CDROM drive does make getting at the battery holder a little easier.

© 2001, d.holmes
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