operating t23 using 12v dc connection with battery removed

[oldcodger]

Can someone tell me if there is a modification I can do to run my t23 directly from a 12v battery. Other laptops can operate this way with the battery removed but the t23 thinks that all power is disconnected when the battery is removed.
Yes I can use an inverter but I would prefer to use direct 12v connection if possible.

Many thanks in anticipation of practical solutions to this small problem

[RealBlackStuff]

Welcome to the Forum.
You can get 12V car adapters, such as this one:
http://www.laptopshop.co.uk/ibm-thinkpa ... -1-ca9.htm
HTH

[oldcodger]

Thanks for the prompt reply. Can you enlighten me as to why the t23 will only operate at 16v and with the battery in place?
Sorry but not the solution I was hoping.

[RealBlackStuff]

I'm afraid I can't help you there.
Must have to do with the electronics on the motherboard.
The T23 battery supplies 10.8V.
A 12V (car?)battery supplies up to 15V and sometimes even more, too much for this laptop.
Have you tried feeding the T23 using the DC-port, rather than the battery contacts?
The pin in the middle is plus or positive, the crescent shaped contact is ground or negative.

[oldcodger]

I do apologise but I thought I was already assuming the power i/p would be the same as is used with the proper ac transformer. I am trying to connect a 12v supply directly to the power i/p with the battery out so I am not connecting to the battery terminals. Or I am again missing something?
Perhaps there is no solution to this but it would be nice to know why?

[RealBlackStuff]

The DC port gets 16V from the adapter, which is "reduced" by the electronics on the motherboard.
I assume that if you feed less than 16V into this DC port, the reduction ends up in a too low voltage for it to run.
And like I said, the T23 battery supplies 10.8V max.
What is effectively required to run this machine I don't know.
Circuit diagrams have never been published, so it's anybody's guess.

[Rick the Green]

13.9 volts is the minimum at witch the T23 will operate from the DC input jack, below that it will revert to battery operation if one is there.
So the hassle free is an inverter & the regular 16 volts adapter.
I used this setup many times on 10 hours car trips (GPS on Laptop)

Rick