Jupio Lithium VPE-10 9V Battery JBL9V SPOT DEAL
This Jupio Lithium 9V Battery lasts up to 7 times longer than a normal alkaline battery. Where a standard 9V battery in a smoke detector lasts about 1 year, this Lithium battery lasts 5-10 years.
A Lithium battery is slightly more expensive to purchase, but it lasts many times longer and is ultimately a lot cheaper. Compared to other chemistries lithium batteries have a very high charge density. Widely used in power hungry portable consumer electronics.