Is LiFePO4 or lead-acid the better leisure battery?

LiFePO4 gives far more usable capacity per kilogram and a much longer cycle life; lead-acid costs less to buy and tolerates being charged by almost anything. The deciding questions are weight, how deeply the bank will be discharged, and how it will be charged.

The two chemistries are sold side by side for the same jobs, and almost every specification on their labels means something different.

Weight and usable energy

For the same usable energy, a LiFePO4 bank is markedly lighter and smaller. In a van, on a boat or anywhere a battery is carried, that difference decides the question on its own. In a garden shed where nothing is lifted, it decides much less.

Cycle life, and how to read it

A cycle rating is meaningless without the two things that qualify it: the depth of discharge it assumes and the capacity percentage the pack must still hold at the end. Two batteries rated for very different cycle counts may be describing the same endurance under different assumptions, and makers that publish both figures are the ones worth comparing.

Charging

Lead-acid tolerates rough charging and slow, partial refills. LiFePO4 charges faster and accepts current more readily, but wants a charger that knows the chemistry, and it dislikes being charged below freezing — many packs simply refuse to, and say so in the manual.

What sits inside the lithium pack

Every LiFePO4 battery contains a battery management system that limits current, balances the cells and cuts off at the boundaries. It is not an accessory: it is the part that decides how the battery behaves when something goes wrong, and it is the least documented part of most listings.

Where this page and the manufacturer’s documentation differ, the documentation is the one to follow. Every capacity, output, input window, current limit, cycle count and temperature threshold on this page comes from the maker’s own published figures, with the unit as printed and the source named. None of it is measured here, and no figure is converted into another convention, because a converted number is a different number. And for any cycle count: the number is set by two qualifiers — the depth of discharge tested and the capacity the pack must still hold at the end. Change either and the same cells produce a different headline. This page reports the qualifiers wherever a maker publishes them, and says they are missing when they are not.