I didn't think that a battery would make such a difference in how powerful my system sounds. I have an RE XXX d2 15'' on a 3000.1 amp. my regular acid battery went to junk within the first two weeks of my new sub. Now with this new battery, I also have a small xs battery to help the juice it takes to move the power hungry sub. My voltage is around 15V with the two batteries and drops around to 14 when im around full tilt. Barely dims lights and I am very happy. My roof in my s-10 extended cab flexes on quarter volume, before it needed to be around 70% to start flexing and rattling. I can tell i've got an extra 5 db atlesast just from a battery swap!! It is bigger than a standard battery so be prepared to do some body work. I got lucky and it fit snug. Now i need a high performance alt to take it to the next level for next summer!! XS for life!!