12V Batteries
Overview
Overview
12V Batteries Overview
About 12V Batteries
About 12V Batteries
A battery is the one part of the setup that wears out by being used as intended.
Everything else on the vehicle lasts until it breaks. A battery has a number of cycles built into it from the day it leaves the factory, and every night you run the fridge is one of them gone. That number is what you are actually buying, and it is decided by the chemistry long before it is decided by the brand.
A car battery is the wrong tool for this. It is built to deliver a huge current for three seconds to turn an engine over, then be refilled immediately. Ask it to feed a fridge overnight and it lasts a season. A deep cycle battery is built the other way round: modest current, for hours, drawn down and recharged over and over without complaint. That is the category, and everything here is one.
Within it the choice is chemistry. Lithium gives you the most usable capacity per kilo and the most cycles, at the highest price and with a management system that needs the right charger. AGM is heavier and gives up less of its capacity before it wants recharging, but it is cheaper, simpler and forgiving of the charger you already own. Slimline formats put either chemistry into a shape that fits behind a seat or under a floor.
Sizing comes from the daily draw, not the shelf. Add up what runs and for how long, work out what the battery can actually give before it is flat, and give yourself a margin for the cloudy stretch where the solar returns half what it should.



