I have one of these--
Amazon.com: Black & Decker VEC1095ABD Smart Battery 25/10/2 Amp Battery Charger: Automotive
It's very light weight since it is an electronic charger vs old school transformer type
charger. $60 with free shipping from Amazon.
There are mixed reviews on Amazon. Some folks found it to be short lived but others
loved it. I've had no problems with mine and it's 4 years old.
I don't use it all the time but when I need a boost I've got it.
I use it with my Honda eu2000 to quick charge my trailer batteries on occasion.
If you aren't in quite that big a hurry I recommend the battery tender plus from
these guys-- Battery Tender Plus
It's $40 bucks with free shipping.
I know you said you wanted a full charge in 24 hours or less but this one is
bullet proof reliable and won't harm your batteries.
It's a 1.25 amp fully automatic charger that you can leave connected long term.
It will give you a decent charge in 24 hours especially if your batteries
are not terribly discharged to begin with.