I recently acquired a 2008 Mercury Mariner Hybrid from a trade. The previous owner told me that the vehicle sat for quite some time before the trade but was running normal prior. After some time going over the vehicle and a general fluid change and new battery it still won’t even begin to crank the engine. I’ve read some other forums talking about the hybrid battery in the back possibly being the culprit. I’m definitely not trying to do anything when it comes to disassembling or servicing the hybrid battery but is there any way for me to charge the hybrid battery or could it possibly be something else causing this problem. Any information would be greatly appreciated.

 

Hybrid and Lithium-Ion batteries go bad quickly when they are left with low voltage for a long period of time. Being that the car sat for a long time, I assume that it has passed the point of no return. As stated on many other electric/hybrid forums, even a fully charged battery will degrade %20 if not used for over a year. This is rapidly increased if the voltage drops too low. I'm not sure how easy the job is on that specific vehicle, but a replacement is the best bet. Any other solutions to recover the battery will be short term, but possibly effective depending on what you expect out of the car.

 

When it comes to Hybrid batteries , The large ones, sometimes sections can be replaced separately . It is a whole new field and hybrid batteries are expensive and the sections are monitored individually.

 

So as off now I did a bunch of research the only code I’m showing is the one that disables the 12v battery due to the high voltage battery in the back being below 300v. It’s measuring about 234.12 v on my scanner. I’ve read about the small button on the driver side access panel on the side of the dash and after charging the 12v battery on the car overnight the little button just flash’s when I press it some other videos show the light on the button going solid and flashes once complete would you happen to know how to get this to work correctly or is there another way to get that voltage back up above 300v