Seems like a lot more safety issues coming to light with lithium batteries everyday. I keep one eye on the lithium stuff, but sleep better at night with AGM. I like the no off-gassing and low maintenance (water) part of AGM's, a little longer life than standard wet cells, and mid cost factor. I guess the thing that keeps me up at night is the proper charging voltage factor for each type. Get it right and all is well. Get it wrong and s--t happens. Keep the smoke inside. Gerry H My inverters are 3 stage charging and were set right Lifeline check it,they came to the conclusion with the AZ heat the batteries charging and no space between the batteries installed in a well vented area for air movement the batteries had a thermal runaway. That is their story and they are sticking to it If revision D is not followed the warranty is void revision D dated 4-14-14 I am not the only person that has had a thermal runaway on AGM batteries