Let me be very clear about this review, this is just my opinion do as you like with this information. This v Max charge pump is a great addition to a sound system here's the trouble Yes it is lithium however it is more of a capacitor rather than a battery which could be great under certain circumstances such as having a true lithium or agm battery as a head unit battery under the hood as well as the addition of an extra battery in the rear to support this v max charge pump to hold a steady 14v+. I'm running a 240 hi output power series alternator and big 3 upgrade with ofc copper 0/1 wire , xs power agm up front ran parallel to the v max charge pump in the rear to support the amplifier of 3k + on 2 12's with 1,500 rms each and I experience voltage drops during the lows from 14.2 down to 12.5 on some songs. The charge pump does quickly recover back up to a solid 14+ volts As soon as you cut the music off but in my opinion this would work far superior with the addition of two batteries plus the v max charge pump for Maximum delivery. THIS ALONE OR ANY OTHER MODEL WILL NOT SUPPORT A VERY WELL BUILT HEAVY SYSTEM WITHOUT THE HELP OF EXTRA BATTERIES AND A HIGH OUTPUT ALTERNATOR WITH THE ADDITION OF THE BIG THREE AND TRUE COPPER WIRE!! with that said , I hope this information helps somebody make a decision before they purchase thinking that this is going to solve their voltage drop issues completely.

Got my vcp6k running with 320a alternator, Power is there! My 2000w, 1000w, and 500w amplifier are very happy now!

Installed on a 2017 Mazda with eloop system. Made my voltage super stable and no more drops running my kicker set up. Super happy

It's crazy. My voltage is so happy and I am super happy. Have this 9 and the 6 in another vehicle. These are the truth