jump packs and trickle chargers

[David Pertuz]

Thought maybe I'd wake the list up from its nap with a question.

I could use another portable jump pack. Something like this:

http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=39954


I went out the other day to see if my car would start - it wouldn't - 
and this topic naturally came to mind. I drive my G20 quite seldom, 
since I bike virtually everywhere in the city and don't leave it much 
except for trips to Detroit, and besides that I was out of the country 
for three weeks. Whereas my Fiat will start up just fine after sitting 
all winter, my G20 may have a very small current drain in the radio 
circuit that makes the car impossible to start after a few weeks.

I actually have one that I've had for years, but some years ago the 
battery apparently died and I don't know how to recharge it or replace 
it. Like a lot of things these days, it does not appear to be 
user-serviceable.

Any easy way to revive the jump pack I have? I suppose hooking it up to 
a trickle charger would work, eh?

Or I could just get a trickle charger for the G20.

Any of these products in particular that y'all find are particularly 
good? Repairable is nice. I don't like disposable products.

David