Have been reading up on AGM (not even considering wet batteries) vs Lithium batteries for my deep cycle house batteries. Now that the Lithium iron batteries are being used that have eliminated fire problems, I have been on AMSolar.com looking at both solar and batteries. With Lithium, you can use all the amp/hr rating and there isn't any degration of output until the very end-think of your cordless drill that goes and goes, then suddenly dies to need recharging. With AGM batteries, you should have twice the amp/hr rating that you should use to get maximum life. So here's the difference in cost: 400amp/hr Lithium battery pack is $3,300. Using 4-Lifeline L16 will give 800amp/hr at about $2,200. Which would you use? Good Luck, TomC