Bentley Bentayga Lithium Battery Replacement: AGM Conversion
Bentley isn't a brand built around shaving weight, but the Bentayga shares its underlying MLB Evo chassis with the Porsche Cayenne and Lamborghini Urus, and that's exactly why it leaves the factory with a lightweight lithium-ion 12V battery under all that leather. When it ages or fails, dealer replacement is a significant expense. We evaluate your car and, where it's a safe fit, convert it to a factory-correct AGM battery instead, at independent pricing.
Shared engineering, unexpected result
The Bentayga's platform-mates are the Porsche Cayenne and Lamborghini Urus, both far more weight-obsessed cars than a Bentley. The lithium-ion 12-volt battery is one of the few places that shared engineering shows up on a car that otherwise prioritizes comfort and mass over grams.
How the pack ages
Lithium cells handle deep discharge and long idle periods worse than a standard battery, and a Bentayga that sits for weeks between drives, common in a South Florida collection, is exactly the pattern that shortens a lithium pack's life. Once a cell group degrades, the pack is typically replaced whole rather than repaired.
What the conversion involves
- We confirm your Bentayga's charging system and electrical calibration are a good fit before recommending a conversion
- The car's electronics get reconfigured so they no longer expect the lithium battery management system
- An AGM battery holds up better to infrequent driving and storage than the factory lithium pack does
What it costs
We don't yet have a confirmed Bentley dealer quote for this exact replacement, but a comparable Lamborghini Urus conversion, on the same shared platform, has been quoted as high as $10,000 at the dealer, so expect similar pricing here. An AGM conversion, for a car that's a good candidate, is a fraction of that at independent pricing.
Related: All services · Bentley service · Lithium vs. AGM battery guide
Frequently asked
How much does Bentley charge to replace the Bentayga lithium battery?
We don't have a confirmed Bentley quote for this exact replacement yet. As a reference point, a comparable Lamborghini Urus conversion on the same shared platform has been quoted as high as $10,000 at the dealer. Call us and we'll help you get a real number for your car.
Is an AGM battery a safe replacement for the factory lithium battery?
In many cases, yes, once we've confirmed your car's charging system is a good fit and reconfigured the electronics for the conversion. Not every car is a good candidate, and we'll tell you honestly if yours isn't.
Will an independent AGM conversion affect my warranty?
No. Under the Magnuson-Moss Warranty Act, factory-correct work performed at an independent shop does not void a manufacturer warranty. We document everything for your records.