The 120ah Cmax lithium battery bank. I've had many questions asked about what's the difference between this battery and the 45ah Cmax option, https://screweduplithium.com/products/cmax/45ah-cmax-lithium-battery-53278689 I'm here to say that both are some of the best lithium batteries in the world! However they both have two distinct advantages, for example the 120ah utilizes the 24ah Cmax cell which although has a lower C rate than it's cousin the 5ah It has over 2.5x on average the capacity versus the typical 45ah, thus making it a great option for people that want to be able to demo their vehicles while they're turned off for short periods of time. I typically recommend this battery for people who want to be able to demo at car shows and audio shows without needing to run their engine and burn gas all day long. The 45ah and the 120ah are both more than capable of handling up to 12,000 watts of amplifier current being drawn from them, however the 45ah will drop without voltage support from the alternator being constantly given to it unless demo volumes are turned down very low. With the 120ah option You can typically demo for a lot longer. As always there are great options besides Cmax as well such as the 10ah Scib lithium battery bank which is an LTO option and boasts an excellent C rating along with a very well-balanced amp hour capacity for being able to demo while the car is turned off with a sufficient enough reserve capacity.