I run two small batteries like that in my trunk. Still save about 20 pounds and have enough reserve for normal stuff.

He's right though, one isn't enough if you have cold weather or any kind of starting issue.

Former owner of '99 CSVT - Silver #222/2760 356/334 wHP/TQ at 10psi on pump gas! See My Mods '05 Volvo S40 Turbo 5 AWD with 6spd, Passion Red '06 Mazda5 Touring, 5spd,MTX, Black