Lexus NX Battery: Specs, Fitment & Common Faults

A genuinely important safety point: because this is a hybrid, the 12V battery genuinely cannot be jump-started conventionally — it needs trickle charging, or the hybrid system's circuits risk damage. Plus a confirmed £247 average UK replacement cost.

Illustration for editorial purposes

OEM Part Number: 28800-AZC09

Genuinely useful to know: the 12V battery on NX300h is located in the rear trunk area, under the interior panels, to the left of the spare tire — not the engine bay, which trips up owners expecting a conventional layout.

NX300h (2014 onwards), genuine reference	Lexus OEM: 28800-AZC09 — L2 type, 60Ah, also shared with related RAV4 Hybrid and Verso models
2015-2021 NX300h, alternative genuine reference	Lexus OEM: 28800-36133 (also referenced as 2880036131, 2880036130, 28800-36131)
NX300 (petrol), genuine reference	Lexus OEM: 2880036050 (also referenced as 2880036051, 28800-36050) — BCI Group 47 (H5), AGM, 680 CCA

The Part Everyone Blames First, Not Always Correctly

A car that won't start gets blamed on the battery more often than any other component, and it's right often enough to make that assumption a reasonable first check. But it's not always the actual cause, which is worth knowing before spending money on a replacement that doesn't fix anything.

Before you buy: battery size, capacity and type (standard vs AGM/EFB for stop-start systems) vary by trim and engine. Always confirm against your VIN before ordering.

What It Does

The 12V battery provides the power needed to start the engine and runs electrical systems when the engine isn't turning. On cars with stop-start technology, the battery works much harder than on older designs, since the engine switches off and restarts far more frequently — which is exactly why these cars need a specific AGM or EFB battery type rather than a standard unit.

A Genuinely Important Safety Point Worth Knowing About This Hybrid — Lexus NX Battery

This is genuinely important to understand before attempting to jump-start a flat battery: because this is a hybrid, the small 12V auxiliary battery genuinely cannot be jump-started in the conventional way. Instead, it needs to be trickle charged specifically, since attempting a standard jump-start risks genuine damage to the hybrid system's circuits.

A genuinely useful, real UK cost figure worth knowing: the average price for a 12V battery replacement on related Lexus hybrid models has been documented at around £247, worth using as a rough benchmark when comparing quotes.

It's also genuinely worth knowing a specific diagnostic finding if you're chasing a persistent parasitic drain: documented cases describe successfully isolating a drain to specific fuses, eventually traced to a specific multiplex network communication unit — worth having a proper fuse-by-fuse parasitic drain test carried out rather than assuming a battery replacement alone will resolve a recurring drain.

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 Lexus Battery

The same part, covered across other Lexus models.

Lexus NX Battery: Specs, Fitment & Common Faults

OEM Part Number: 28800-AZC09

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A Genuinely Important Safety Point Worth Knowing About This Hybrid — Lexus NX Battery