Bill Daniels wrote:

I think I could build a box for an internal laptop battery that
would have contacts and a restraining latch. Just push the battery in until
it clicks - no wires to futz with.

Perhaps a suitable solution for a knowledgeable person like yourself,
but the typical laptop battery has a half-dozen contacts, so I wouldn't
know which ones need connecting. I don't even know if the charger can be
connected directly to battery, or if it goes through some other
circuitry in the laptop. These issues don't exist with external laptop
batteries, and their approximately 4" x 6" x 1" shape would make
mounting them easier than the oddball shapes the laptops use. We already
futz with one cable out a lead-acid glider battery - not a problem there.


Many laptops and gadgets sit on car seats in the sun and then get turned on.
I have certainly done that but I don't know of any problems. I remember
trying to boot a laptop I left on a car seat in Phoenix. It was so hot I
couldn't hold it. After it booted, I couldn't read the LCD until the A/C
cooled it down. Generically, Li-ion polymer batteries are tolerant of
temperature extremes. The laptop batteries are regarded as 'smart'
batteries in that they have processor chips inside that manage them.

I don't know how smart a laptop battery is, and I suspect some of the
smarts are inside the laptop; for example, in the situation you
describe, the laptop likely cut back it's processor speed and LCD
brightness to reduce the power taken from the battery, protecting it
from overheating. The battery used by itself might not be able to
protect itself properly, because it's designed to be used only in the
laptop. The external batteries might offer this protection, since they
are intended to be used by themselves. I don't know if that's true, but
I'd like to know before I started using one in a glider.

I think they may even limit the voltage to 14.8V.

A number of the external batteries can be set to different output
voltages, which might be useful, but I don't know how they do that.

--
Change "netto" to "net" to email me directly

Eric Greenwell
Washington State
USA