It's more about the long term storage than the cost. Let's say a set of new batteries last 20 days in a mechanical device. If that device is in a remote location, someone would have to go there every 15 days and change the batteries. With the new nano multicell, you would only need to visit every 120 days if it had 6 compartments. The batteries would cost more, but the savings in trips to the site would be tons of money. Say 20 miles to the site at $4/gal gas is $8 a trip for $40 gas savings. Got to pay someone so 2 Hr trip time at $30/Hr salary is $60 a trip for a savings of $300. Total saving is $340.