PowerBook 540c batteries

Question

PowerBook 540c batteries

Hi,
Two questions actually...
1.
I have a PowerBook 540 c modified to a PowerPC 120MHz processor.
It is terrific BUT I believe the internal battery is dead(?) as the time resets to 1970 after I restart.
Is this the case and what should I do? Changing an internal battery requires a specialist I guess?

2.
I would also like to get a battery as an alternative to being tethered to the power cable. Where can I get a working battery? Is this possible nowadays?

This PowerBook is terrific and complements my new 12 inch G4 🙂

Cheers.

Michael

PowerBook 540c, Mac OS 8.6 or Earlier, modified to PowerPC 120 MHz

Posted on Mar 28, 2006 4:52 AM

Reply

Answer 1

Mar 28, 2006 10:42 AM in response to Michael Vallance

You may look at(for take apart,battery,PRAM-battery) at:
http://www.whoopis.com/computer_repair/#portable
and for PRAM -battery(US$9,95) at
powerbookguy.com

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Answer 2

Denis Eddy

Level 4

3,571 points

Mar 28, 2006 11:55 AM in response to Michael Vallance

Michael
Be encouraged to know that replacement of the backup battery (616-0021) of the 500 series necessitates almost complete disassembly of the PB. The battery's cable is connected into the trackpad harness, and it must be tucked into place 'just so' to enable the case top and bottom to be reassembled without fouling it. Painstaking, but possible.

The normal backup battery is 30mAh capacity. There are some of 50mAh to be had.

The difficulty with the main batteries is the intelligent (hah!) management system by the contained microprocessor. Apple never again offered NiMH batteries with such a management system. In my experience, at most only half of the number of old (now very old) batteries can be resuscitated without recelling them. However, new new M1893 (also M1906 and M1910) NiMH batteries made in China can be had in Australia for about AUD80. They also have greater capacity (about 2300 mAh as opposed to 1800mAh). There is bound to be an eBay seller of them in the US, and I believe that the price is even less than the dollar conversion would lead one to expect.

Heaps. All upgraded. System 6.0.8 to OS 10.4.x

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Answer 3

Mar 29, 2006 4:31 AM in response to Denis Eddy

Many thanks for an insightful and informative reply.
I'm currently in Japan and expect to be in Australia later this year for a conference.. I'll do some preparation and see if I can indeed get a relacement battery. As for dismantling the PowerBook .. gulp! I'll live with the date issue.
Cheers.
Michael
--

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Answer 4

Denis Eddy

Level 4

3,571 points

Mar 29, 2006 4:59 AM in response to Michael Vallance

Michael
The backup batteries of (most) older PBs are made of sterner stuff than the main batteries, and if you are ever able to charge a main battery fully you may find that your present battery will begin to recharge. This is a design feature, I gather, and mostly borne out by observation.

The principal, if not unique, source of new main batteries in Australia is the eBay seller (boom, tish) aussie_battery, located in the Haymarket, Sydney, but with no shopfront access.

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