I recently installed an Alpine MRP-M2000 in my car and i was wondering what other upgrades i should do. Ive done the big three with all 0 gauge, im going to get a new optima yellow top for my main battery and maybe one to go in the trunk.But do i need an isolator or what, and i was considering a HO alternator.

assuming 14.4 volts, you'll need ~139 amps just to cover the 2000 watts the amp can draw. i don't know if that'* peak or RMS, but that'* still a huge draw.

What is ur reason for installing an Isolator?

no isolator, and might wanna think about a beefier alt, the 2 batts will help too for sure.

An isolator is actually a good idea. You need something inbetween the batteries to keep them from fighting when the car is off. The way it was explained to me is without something to stop the flow of power, the batteries will trickle a little power in between them and cause a wave effect where they eventually are sending large amounts of power back and forth until one or both goes bad.

connect two batteries together and if they were both at the same voltage before the connection NO current will flow in either direction. if one self-discharges faster than the other, it'* terminal voltage will lower, but the one that doesn't discharge as quickly will flow current toward it until it is at the same voltage as it is. they will keep each other at identical voltages, that will be the only time they transfer current between one another. this "wave" concept does not exist, unless one of the batteries drops a cell, in which case the good battery will throw a LOT of current toward the bad instantly and continue to do so until it'* drained itself down to the level of the bad.

this all works on the same reason why if you connect two 12 volt batteries together with jumper cables, if you see a spark, one was obviously discharged, but no spark means no flowof current(equal voltages).

most is correct.. but if u install a isolator.. your voltage wont increase which is a big reason people install a second Batt.. but u can run ur stereo with the car off and only drain ur aux batt.

Actually I meant relay (solenoid) not isolator, my bad. The relay setup is how I have mine so when the car is off, one battery powers the car and after you start it both batteries are live and can charge. I've also heard both sides of the story when it comes to the batteries fighting each other, and it may have a lot to do with the two batteries that you are connecting. In my case I have two completely different batteries and would rather be safe than sorry. I also like having the peace of mind that I can leave the stereo on with the car off until the battery is low, and still start the car with the full battery.

Your factory alternator is IIRC 105 amps. If you want to push 2000 watts for any extended period of time, you'll need a higher output alternator.

The birth sheet for the amp says 2,100 watts RMS at 2 ohms which is how i have them wired.