The answer to this age old question of Leaf 12v batteries has 2 solutions... First, you do not need a L-ion battery, or AGM deep cycle. The 12v electrical system does not require any cold cranking power (like starting a big engine), so the stock one is adequate. If you want an upgrade, get the biggest that fits in the battery tray, or even get a bigger tray, and you can have a good, powerful, Lead Acid battery that can last 10 years, like most of my car batteries do.
Second, it is not the size or type of battery that is important. Dead Battery problems do not happen suddenly, but over time, when we are not looking. My 3 year old battery is in NEW condition. I know this because I have installed a digital volt meter that tells me the battery voltage at all times when I drive. You can get one reasonable, and install it in the cigarette lighter, or hard wire it. When you see the battery voltage start going down, then you can investigate what your car is doing....
Last edited by powersurge
on Mon Nov 20, 2017 10:20 am, edited 1 time in total.