On 2011-02-21 05:42:43 -0800, whisky-dave said:

On Feb 19, 4:26*pm, (Dennis Boone) wrote:
* If one knows the voltage for the laptop, they could make a 12 to 24
V
* input DC|DC converter that outputs the right voltage to the laptop.
*(A
* technician with nothing to do in his spare time should be able to ge
t
* the parts, assemble and test this in no time).

Um, it's not quite trivial. *Most boost converters are low-current
devices. *Most laptops these days require between 5 and 8 amps, at
their nominal input voltage, to operate. *That's a lot of current
for a throw-together project.

I think Apple advise not to run a laptop without the battery present
as the 'power' from the converter isn't enough to fully drive the
laptop.
Although it's probbaly be OK for most things.

Current MacBook Pros do not have a user replaceable battery. I am not
sure of the lesser MacBooks. My Old PowerBook Pro (a PPC or non-Intel)
machine has a user replaceable battery and it is possible to run that
without the battery. That option is not possible with the Intel
MacBooks.

....and as I have said I use the Kensington Power Inverter which is able
to power the MacBook Pro 85W power supply without issue.
http://us.kensington.com/html/17163.html



You _can_ get these things, but they're typically the size of your
laptop's existing power supply. *Some laptop vendors actually put
the functionality in the laptop supplies in the first place. (Dell)
Otherwise, look at the likes of Targus.

De


--
Regards,

Savageduck