Lexus RX 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 UK cost figure and an honest account of unhelpful owner correspondence.
Illustration for editorial purposes
Opens live listings in a new tab.
OEM Part Number: 28800-AZC09
| RX450h GYL25 (2016 onwards), genuine reference | Lexus OEM: 28800-AZC09 — L2 type, 60Ah, shared with NX300h |
|---|---|
| RX450h GYL10/GYL15/GGL (2010-2015), genuine reference | Lexus OEM: 28800-31291 (also referenced as 2880031290, 2880031292) — Panasonic-made |
| RX450h GYL15 (2008-2015), alternative reference | Lexus OEM: 28800-31293 — S55D23L, 51Ah, Panasonic-made |
Lexus RX Battery: The Part Everyone Blames First, Not Always Correctly
On the Lexus RX, 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.
Lexus RX Battery: What It Does
On the Lexus RX, 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.
A Genuinely Important Safety Point Worth Knowing About This Hybrid — Lexus RX 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 that powers the electronics 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. It's worth keeping a proper trickle charger on hand, or knowing where to source one quickly, rather than reaching for jump leads if you find the battery flat.
It's also genuinely worth knowing a specific, useful diagnostic finding if you're chasing a persistent parasitic drain: one documented case successfully isolated the drain to two specific fuses, eventually traced to a specific multiplex network communication unit — removing this component caused the excess current draw to stop entirely. Worth having a proper fuse-by-fuse parasitic drain test carried out rather than assuming a battery replacement alone will resolve a recurring drain if the underlying cause hasn't been identified.
Lexus RX 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 Lexus Battery
The same part, covered across other Lexus models.