[Ham-Mac] Using external battery to power a PowerBook

[Phil Stripling]

Dick Rucker [rrucker@bellatlantic.net] wrote:
>SNIP< 
> I booted the G3 from its internal battery, then plugged in my external
> batteries, and monitored the current drawn.  Regardless of whether I had one
> battery, or two batteries in series, the current drawn by the G3 when the
> external power cable was attached was about 25 mA.  So obviously, the G3 was
> still using the internal battery and ignoring the external supply.

You have answers to your real question, so let me pose an alternative
to your comment above: Are you sure your G3 is ignoring the external
supply? 

Louise and I use small SLABs as back up power to our handheld transceivers
during long events. When we either are told we're fading or suspect it's
been long enough and do a pre-emptive switch, we plug a line in from the
SLAB to the recharge socket on the radios. This _does_ recharge the
internal battery. When we've been told we've lost power,  the SLAB either
powers the radio directly and recharges the internal set of batteries (we
only use rechargeables) or it boosts the batteries enough to continue
running and begins to recharge. I don't think this is a problem.

Is there a way to tell if your internal battery is being recharged along
with continuing to power the computer? I know our iBook knows when it's
got the recharger plugged in, but I have no idea how the electronics
handle the incoming power vis-a-vis recharging the internal battery and
providing power to the computer. Our iBook shows a distinctive icon when
plugged into the wall; what indication do you get from your computer
regarding the source of power?

-- 
Phil Stripling
The Civilized Explorer
http://www.cieux.com/