Specifications
Battery
- Technology
- Flooded (lead-acid)
- Voltage
- 12V
- Capacity
- 35Ah
- Cold cranking current (EN)
- 520A
- Length
- 212mm
- Width
- 175mm
- Height
- 140mm
- Terminal layout
- 0 — positive right
- Terminal type
- T1 standard (EN)
Why this one
01
Backup duty
Keeps electronics and safety systems powered while the starter battery cranks.
02
Vent and flame arrestor
EN-compliant degassing vent with a flame arrestor for safe gas release.
03
Maintenance-free
No topping up needed in service.
04
ETN 535106052
Short code AUX1, case POB, for a quick match to the fitted battery.
On the job
What it does
Many modern cars carry a small second battery next to the starter battery. It keeps voltage steady for electronics and comfort functions while the engine cranks, stretches start-stop phases, or backs up safety systems. The AUX1 is a flooded unit in the low POB case, 212 x 175 x 140 mm, with an EN-compliant vent and flame arrestor.
Before you fit it
Auxiliary batteries vary a lot between makes, so compare dimensions, capacity, terminal layout and hold-down with the original before ordering; a few millimetres of height matter in a tight bracket. When the auxiliary battery fails, test the main battery and charging system too, as they usually age together.
