The battery is shot in my IMB 600 series 2645-4BU. It works while it's plugged into an electrical outlet. Which battery should I replace? The main battery or the secondary 'Ultrabay' battery (as IBM calls it)? Both? Any information would be greatly appreciated.

-a

I would replace the battery that is shot... the main one. If the other battery is shot too, either replace it or remove it.

I've never examined the insides of a notebook PC. Does it come with a wafer-sized battery to maintain the system clock? I know on regular PCs there is a small battery connected to the motherboard. Sometimes this battery must be replaced too, or the system clock will drift.

I have that same model Thinkpad. The battery has been shot for several years and the computer has been running just fine off the charger. A Thai friend of mine has been using that machine for the past six months or so because I purchased a new Thinkpad. He keeps it plugged into a UPS in case of power failures. I thought about buying a new battery but they are expensive and you don't have any idea of how old the "NEW" battery actually is.

I recently ordered a non-OEM battery replacement for a Dell laptop from Yock-Asia.

The non-OEM I bought from Yock-Asia was $40 USD. That price included shipping it to me here in Chiang Mai. The OEM Dell battery sells for around $100 USD and I doubt if that includes shipping.

The "non-OEM" battery could very well explode and catch fire tomorrow, but it performs and appears great today.

Thanks for the replies, gentlemen. The computer runs fine while plugged into an outlet and it will probably run for years until the screen fails. I'd still like to use it while I'm on the go.

-a

Options are:

1. Get a new genuine battery from an authorized dealer. Pretty expensive.

2. Get a battery from Chinatown or somewhere other place. Cheaper, but maybe a bit risky.

3. Get the battery re-packed. Amorn in Chinatown, IT Mall, and Zeers does this. You basically replace the "guts" of the battery with equivalent cells. Much cheaper, but it doesn't look that good.