DC powered Portable Bass Amp?

[skypn]

Short story long
Kid plays sax, and wants to do Christmas Carols door to door next year with My Bro on snare, and myself on bass. I looked at (and used to own ~30 years ago) a Pig Nose, but I heard that pushing a bass through one might muke it up. If that's incorrect, tell me, and problem sloved.

I don't want to spend more and $100 on this.

I thought maybe I could build something as I am handy with a soldering iron and do woodworking. IF I did build my own I'm only looking at maybe an 8", 10" speaker at most.

Google searches for an amp circuit left me dizzy.

I'm starting to think that maybe I'd be better off trying to run my Rumble 15 through a marine/car battery with a converter built in their own (vented) box, and strap the cluster to a luggage "hand truck". I would have no idea how long a set-up like this would play before the battery would die.
Obviously I'm not looking for "true" bass sound, just some that doesn't sound like utter crap.

Any suggestions would be appreciated.
TIA

[BassmanPaul]

Maybe an acoustic bass guitar might fit the bill. So can get quite loud.

[waleross]

Here is a link for the Pignose Hog-30 that I recently bought. You might want to take a look at it. It holds a charge for a long time and it gives a great sound for a portable amp. Just great for my around the house playing without plugging it in. I'm sure there are others but in this class Pignose's are great . Pignose*Hog 30 Amp - Find the largest selection and guaranteed lowest prices at Musician's Friend.