What does ‘thin size’ mean on the 12V EU lithium batteries, and where do they fit?

Direct answer: “Thin size” on these pages describes a narrow, tall case. The 12V 100Ah EU battery is listed at 395 × 110 × 286 mm, the 150Ah at 552 × 110 × 288 mm and the 180Ah at 580 × 132 × 242 mm. That is narrower than the common box shapes, so they suit slim compartments, but they are longer. Check length, width and height plus terminal clearance and mounting orientation against your space, and confirm orientation with Redway.

Published figures. 12V 100Ah EU: 395 × 110 × 286 mm, 9 kg, 1,280 Wh, 100A continuous, 110A peak for 10s. 12V 150Ah EU: 552 × 110 × 288 mm, 12.8 kg, 1,920 Wh, 100A or 150A continuous by version. 12V 180Ah EU: 580 × 132 × 242 mm, 15 kg, 2,304 Wh, 100A or 150A. All three list IP65, an ABS case, M8 / T8–T20 terminals and a 3-year warranty.

A data point to confirm: the 150Ah EU page title says 150Ah and its energy (1,920 Wh) matches 150Ah at 12.8V, but its capacity row reads 180Ah. Ask Redway to confirm the capacity in writing before ordering.

How they compare. The standard 12V 100Ah page lists 260 × 168 × 210 mm (BCI Group 24), and the 12V 150Ah 330 × 172 × 215 mm (BCI Group 31). The thin versions trade width (110–132 mm instead of about 170 mm) for length and, on the 100Ah and 150Ah, height. Our arithmetic: the 100Ah EU case is roughly 135 mm longer and 76 mm taller than the Group 24 case.

Fit checks. Measure the space, then add room for cable lugs and bends above or beside the terminals, a fuse or isolator if it sits next to the battery, and air around the case. Check whether the battery can be installed on its side or end if your space needs that; the pages do not state permitted orientations. Check floor strength and how the battery will be strapped or bracketed, since the case is ABS.

Electrical checks. The thin packs share the 14.6V charge and 10V cut-off of the other 12V models and allow up to four in series or parallel, so the charger and inverter rules are the same. For sizing loads, see sizing a 12V battery for RV loads.