The issue with regular lithiums like LiFepo4's, like solar batteries you see, LiFepo4 batteries is they have 25-50, 100 or 200 BMS control units on them which is fine if you don't expect to exceed the burst rate they are rated for. For instance, a $250 100ah LiFepo4 from Litime will give you enough burst current up to 285A but only for about 5-7 seconds before the BMS kicks in an limits it to prevent damage to the lithium bank. That's because they are not geared to audio but are fine with systems that draw less than continuous BMS rating. The Glow or other Lithium Titanate batteries are designed without those limitations in mind. Start with the amount of wattage it will cover then get the most storage you can afford in that range that is tailored to the use. If you don't need off motor hours, then any really good lithium abnl that provides enough continuous power is fine. The series 1 is better capacity and good output, the 2 is for greater output and about half the reserve and the 3 is what I deem a competition bank, balls to the walls power but little reserve. If you only need support for a 5000 watt system, no need for the series 2 or 3. Keep in mind that you can get all of it if you want to plunk down serius cash and get 4 of any of them in a series parallel configuration, but why would you unless you have a 50000 watt system and 4 alternators, which you don;t.