Portable AC power source?

Charles Curley charlescurley at charlescurley.com
Wed Jan 27 11:27:00 MST 2010

On Wed, 27 Jan 2010 10:42:37 -0700
D <p-collector at gmx.com> wrote:

> Anyone know of a good PORTABLE AC power source? Something like a UPS
> or something, but smaller. It doesn't have to be big, just enough to
> power a couple of external devices to my laptop.

Simplest solution: an inverter. Get one specifically designed for solid
state electronics, e.g. laptops, etc. It must produce a sine wave, and
if the salesman doesn't know what a sine wave it, it doesn't. For what
you are doing, a 140 watt inverter is fine. My Lenovo R51 is rated for
70 watts and actually draws around 40.

This, of course, requires a power source. Your car will supply any good
inverter just fine. Plug it into the power point (cigarette lighter to
us dinosaurs) socket and away you go. Just be sure that the inverter at
full load won't blow the fuse.

For longer term (camping, running while the engine is shut down, etc.),
a deep cycle battery and an alligator clip to power point cable will do
it. Put a fuse on it. I use the in-line fuse holders as that's what my
car has, and that way I can draw spare fuses from the same supply.
Also, put the battery into a battery case, just in (ahem) case. The
battery and case should be readily available at marine, RV and solar
power vendors. Try an auto parts house for the cable and fuse holder.

For charging the battery from the mains, a 1.5 amp trickle charger does
just fine. For faster charging, get a higher capacity charger. However,
the faster the charger the more likely it is to damage the battery by
charging too fast.

To charge the deep cycle battery while driving, get a vehicle to
vehicle battery booster cable. These go power point to power point. I
use a Black&Decker Simple Start, catalog number BBC2CB. It has smarts
on it, and delivers about 8 amps.

I use this to run my mobile refrigerator, and it's good for several
days without charging in the car even in hot Arizona summer sun.

Of course your definition of "portable" may preclude a deep cycle


Charles Curley                  /"\    ASCII Ribbon Campaign
Looking for fine software       \ /    Respect for open standards
and/or writing?                  X     No HTML/RTF in email
http://www.charlescurley.com    / \    No M$ Word docs in email

Key fingerprint = CE5C 6645 A45A 64E4 94C0  809C FFF6 4C48 4ECD DFDB

More information about the PLUG mailing list