Speakers is killing my battery?

I have 2 12" cvr kickers hooked up to a kenwood 1000 watt amp, I have been through two new brand battery within a year(thank god I had a warranth) but I noticed since I switch amps, I had a 1500 watt d cl bazooka amp hooked up I didnt have no problem until I switch to the kenwood, so I figured the amp was up to high so I low down the b and gain on the amp and its still causing my headlights to blink everytime the subs hit, im thinking bout hooking back up that bazooka. What might be the problem?