Renault Megane Battery: Specs, Fitment & Common Faults
On the Megane, a genuinely surprising real root cause: a faulty immobiliser control unit caused a drain that stumped two dealers for three weeks.
Illustration for editorial purposes
Opens live listings in a new tab.
OEM Part Number: 540-640A
| Most petrol engines (Megane II), Type 027 | 62-64Ah, 540-640A (EN) depending on grade — 242mm case |
|---|---|
| 1.9 dCi diesel, Type 096 | 278mm case — genuinely larger than the petrol fitment |
| Megane III/IV, standard fitment | 207-278mm length depending on engine, 175mm width, 175-190mm height |
A Genuinely Surprising, Real Root Cause Worth Knowing About — Renault Megane Battery
If you've had two dealers and an auto-electrician all fail to find a persistent battery drain, this is genuinely worth knowing: one documented case, after three weeks of unsuccessful diagnosis, was eventually traced to a faulty immobiliser control unit itself — replacing it resolved the drain completely, with no reoccurrence six months later. This is a genuinely surprising root cause, and it's worth mentioning specifically as a possibility if you've already exhausted the usual suspects (interior lights, glovebox, boot light) without success.
It's also worth checking the glovebox door itself, not just the bulb: the plastic door can genuinely warp slightly over time, meaning the side that operates the internal switch retreats away from the switch plunger, leaving the light triggered even when the glovebox looks closed. If you've already removed the bulb and the drain persists, checking the door's fit and alignment against the switch is worth doing.
Renault Megane Battery: The Part Everyone Blames First, Not Always Correctly
On the Renault Megane, more non-starts get pinned on the battery than on any other single component, and that assumption is correct often enough to justify checking it first. It's not always the real cause, though, so it's worth confirming before spending money on a replacement that doesn't fix the problem.
Renault Megane Battery: What It Does
On the Renault Megane, every engine start and every moment the electrical systems run without the engine turning draws on the 12V battery. Stop-start puts far more demand on that battery than older designs, given how often the engine cycles off and on — hence the need for an AGM or EFB battery instead of a standard type.
Opens live listings in a new tab.
Renault Megane Battery: Warning Signs, DIY Difficulty & Aftermarket Advice
These are the same regardless of make or model — see our full Battery Guide for warning signs to watch for, confirming fitment against your VIN, and matching the right technology (standard, EFB, AGM) when buying aftermarket.
More Renault Battery
The same part, covered across other Renault models.