In message om, Dave
Liquorice writes
On 29 Aug 2004 14:19:15 -0700, dg wrote:

If say, I wanted to power a laptop this way (mains transformer = 12v
and 4.16A) how long could I expect the car battery to last?

Quite a long time 12 hrs maybe longer but I doubt that a car battery
would survive this sort of treatment for very long. They are designed
for short high current use and immediate recharge. Not for long slow
discharge to almost nothing.

Most laptops run of a higher voltage, e.g. looking at my laptop PSU,
it's 19.6V output


--
geoff