Pierce

The information I have gleaned from non-Lincoln hybrid threads (some of which are extensive) is that the 12V battery does not start the engine, but does start the hybrid battery, which in turn starts the engine. In other words, if your 12V battery dies, you're stranded, even though it doesn't directly start the engine. I presume this is also true for Lincoln MKZ hybrids.

Thanks for all the replies. I'll replace it soon. I'm pushing up against the end of the 4 year warranty. Does anybody know if there's a test standard below which the dealer, with Lincoln's agreement, will treat replacement as a warranty item? Or is their position that until the battery needs repeated jumping, or fails entirely, replacement is the customer's responsibility? (I've never had any issue starting the vehicle.)

Could declining MPG on similar drives be one of those quirky things that an aging 12V battery might cause?

I have a 2015 MKZ Hybrid with 41,000 miles (bought new). How long (and/or how far) should I expect the 12V battery to last? Have some of you chosen to replace yours at a certain age and/or mileage, rather than to wait for clear symptoms (or a total failure without warning)?

I've got a 2015 MKZ Hybrid, which I bought new. I've put 40,000 miles on it. I noticed my mpg declining over time, and wondered whether battery degradation might be the cause. I started reading here and elsewhere in the forum. I'm puzzled by a statement above and elsewhere to the effect that the battery is covered by the 4 yr/50,000 mile warranty. I've also seen statements that 4 years is about what to expect out of these batteries. My warranty says the hybrid battery is covered for 8 yr/100,000 miles. (Given the cost of a hybrid battery, I would never have bought without this warranty length.) Am I missing something about battery warranty length? If not, it would seem that any large scale battery mismatching would be a huge financial issue for Lincoln, rather than its customers.