The Lifeline press release is not exactly factual. Lead acid batteries can only be discharged to about 50% capacity if you want any cycle life out of them. In addition, it takes a long time to recover the last 20% of charge. So if you need 100 AH of capacity, you need at least a 200 AH bank, possibly more depending on recharge times. Lithium on the other hand, can be discharged to 20% with exceptional cycle life, and recharge much more quickly to 100%. So if you need 100 AH capacity you need only perhaps a 125 AH bank.
They are still a very new technology though, and not cheap, even considering cycle life and useable capacity.
