PM'd

The "good reason" is they are cheap.. Most batteries are the same.. No reason to spend tons of $$$.. they can drain and recharge over and over till they are done.. Interstate makes a quality battery.. And the remans are often a great deal.. They have plenty of AMP/HRS to drive 4 JL Amplifiers for about 4-5 hours at 3/4-100% full volume.. (although to be honest I did not experience one failure all last year from the bats being drained)..

The key is to make sure they have water!!! if not.. ANY fill battery will explode when left on a charger.. (so.. my fault not the battery)..

The batteries I use are dry-cell's. Don't have to worry about all that.

Just a peek at the Subs going in. I will post pictures of this project as it comes together.
JL 12w7's

How much air space is in there? They look tiny, especially with the displacement of the woofers.

They are a little small. There only1.8 cu/ft. I may have to expand them alittle wider. I don't have much room on the starboard side to go much wider because of the battery switch. Also, I am mounting the amps in the middle.

Sealed calls for 1.875 and displacement is .21, so looks like you've got it pretty close, as long as it's completely sealed.

what about a solar baric style sub? Dont they require less space? 12 inch,box size,cf

solo-baric, and most woofers these days take the same amount or a little bit more.

a 12 1 cubic foot?