thanks and a Thinkpad power supply question

Archived from groups: comp.sys.laptops (More info?)

Thanks to folks in the group who helped me with info sources, I got my
first Thinkpad today through E-bay. A T21. It is great. Thank you
to you all.

Though it's only about 1 1/2 years old, I understand, it doesn't look
like the battery will last too long. I need to time it, but I think
it's going to be 1 to 1 1/2 hours.

So here's the question: the AC supply puts out 16 volts dc. Does the
Thinkpad need that full 16 volts to run and take a charge? Will it
take a good charge from that same connector using a 12 volt dc battery
- like a small 12 volt gel cell? Or do I need to make up a battery
pack that gives out the full 16 volts? The idea is I could carry
along a battery pack to increase the on-time.

Dumb idea, or OK to try?

Jim

Archived from groups: comp.sys.laptops (More info?)

On Mon, 18 Oct 2004 23:53:52 -0500, jim_demian@hotmail.com wrote:

>Thanks to folks in the group who helped me with info sources, I got my
>first Thinkpad today through E-bay. A T21. It is great. Thank you
>to you all.
>
>Though it's only about 1 1/2 years old, I understand, it doesn't look
>like the battery will last too long. I need to time it, but I think
>it's going to be 1 to 1 1/2 hours.
>
>So here's the question: the AC supply puts out 16 volts dc. Does the
>Thinkpad need that full 16 volts to run and take a charge? Will it
>take a good charge from that same connector using a 12 volt dc battery
>- like a small 12 volt gel cell? Or do I need to make up a battery
>pack that gives out the full 16 volts? The idea is I could carry
>along a battery pack to increase the on-time.
>
>Dumb idea, or OK to try?
>
>Jim

Jim,

You can get an auto/air adapter at Radio Shack wihch plugs into a
cigarette-lighter socket and has an adjustable output and removable
tips. It has the correct tip for a Thinkpad, and the output is easily
adjusted for 16 v. Once configured, this works very well either
powering from your automobile, or a 12 v gell-cell battery. I couldn't
get the Thinkpad to run with only the 12v out of the gell-cell though.
(I had two Thinkpads at the time, an old 365XD and an A-30, and had
the same experience with each).

There are also special battery packs available, but they are
expensive. Overall, if cost is your primary concern, a second battery
is your best option. Check ebay carefully and you can get a good deal.
If the T21 takes Ultrabay accessories (the A30 did) then an Ultrabay
battery is the way to go. otherwise, just add a second main battery
and keep your "marginal" battery as a spare.