Deep-cycle means a different plate, not a bigger number
A leisure battery is built to be emptied slowly and refilled often, which is the opposite of what a starter battery is built for, and the difference is in the plates rather than in the label. Capacity is published in amp-hours at a stated discharge rate — usually over twenty hours — and the same battery drained in five hours delivers noticeably less; a listing that prints amp-hours without the rate is describing an ideal. Construction separates the shelf: flooded cells are cheapest and need checking, AGM absorbs its electrolyte in a mat and tolerates vibration and mounting angles, gel handles deep discharge but wants a gentler charging voltage. That charging voltage is a specification, not a detail: an AGM battery on a charger set for gel never reaches full, and a gel battery on an AGM profile is cooked slowly. Depth of discharge is the figure that turns a capacity into a usable capacity — half of a lead-acid battery is generally as far as it should go, where a lithium one goes much further — and it is the honest way to compare the two chemistries at the same price. Then terminals, dimensions and weight, because a battery that does not fit the locker is not a candidate. We compare capacity and its discharge rate, construction, depth of discharge, cycle life, charging voltage, terminals and dimensions.
100 Ah at 12 V · AGM, sealed and maintenance-free · over 600 cycles at 50 % DoD · self-discharge under 3 % a month · −20 °C to +50 °C · M8 terminals · 330 × 172 × 217 mm · 22.5 kg
A 12 V 100 Ah sealed AGM leisure battery rated for over 600 cycles at 50 % depth of discharge, with a published temperature range and a self-discharge figure.
Best for: A garden building or a standby installation where the battery sits for long periods between uses.
≈ €120
80 Ah at 12 V · AGM, maintenance-free · up to 55 % usable capacity · up to 700 cycles · low internal resistance · sealed and vibration-resistant
A 12 V 80 Ah AGM deep-cycle battery rated for up to 700 cycles, and the only battery in this catalogue whose listing publishes a usable capacity figure.
Best for: A van fit-out where the working capacity, rather than the rated one, is what the budget is built on.
≈ €128
100 Ah at 12 V · AGM, sealed · terminal clamps, positive on the right, plus 19.5 mm / minus 17.9 mm · supplied filled and charged · 2-year warranty · 278 × 175 × 190 mm · 21.5 kg
A 12 V 100 Ah sealed AGM leisure battery supplied filled and charged, published with terminal post diameters and polarity, and explicitly stated not to be a starter battery.
Best for: A direct replacement in a caravan tray where the existing clamps must fit the new posts.
≈ €130
140 Ah at 12 V · AGM with glass fibre mats · 850 A (EN) · deep-discharge protection named · positive on the right · dimensions published with a unit error in the listing
A 12 V 140 Ah AGM leisure battery quoted at 850 A to EN, described as gas-tight and suitable for indoor use, with a deep-discharge protection named.
Best for: A motorhome with a mover, where the high current figure is the relevant one.
≈ €183
A price quoted in the text of a PowerVerdict page dates from the day that page was written; the live figure beside each product is fetched while you read and replaces it.
