[okusa]

6 months ago my OEM battery died and I replaced it with the smaller, lighter one from the Z4M. Then, I added a sub and JL Audio 12W3v3-2 in January. Since then, I've experienced increased battery discharge warnings after driving with the sub running for about an hour and I've had to keep the battery on a tender at night (I never run the stereo when the car isn't running). So, I unplugged and removed the sub and the problems went away. I've been running it like that for about 2 weeks with no additional problems which that tells me there's no parasitic leak somewhere and the problem is the battery strength.

So, my questions is - what is the best battery to upgrade to so I can avoid this problem in the future?