My 2018 F-type 400 Sport is giving me a message saying "Battery Low - Please Start Engine." I bought this car used a couple years ago and the CARFAX report doesn't show the battery being replaced. Can anyone tell me which battery this message is referring to? Is it the main battery or the accessory battery? Also, if I replace one battery, is it best to replace them both, or can I replace each one individually as they start to die?

 

You have a newer F-TYPE so only 1 battery. Earlier F-TYPEs had 2 batteries.

 

It is the main battery in question. The secondary battery, if your car has one, controls ONLY the annoying start/stop nonsense. If that battery is disconnected or fails the only effect is freedom from the annoyance - nothing else is affected. Many of us purposely remove the secondary battery from the equation…the later cars do not use a battery for the start/stop system but the system can still be disconnected without any other issue.

If you install a new main battery you MUST, MUST make sure that it is fully charged at installation. Low battery voltage in modern cars, including your F-Type, results in random systems not functioning properly and associated warning lights coming on. Your car has now told you that the battery voltage is insufficient! If you have access to an electric outlet the best idea is to permanently install a battery minder to keep the battery at full charge - there are various brands, the favoured one being CTEK.

 

You have only one battery. Only the first two years had a secondary battery and that only controlled the eco stop/start.

 

Thank you everyone for the input. I wasn't sure if my 2018 had one battery or two. My 2014 had two and I have been searching online for information on my 2018. Unfortunately there is a lot of has unreliable information on the internet and I have seen posts stating that my car has one battery and I have seen posts stating that it has two. This forum is a great source of information and I appreciate it from everyone.

 

Ideally, once you install a new battery, you should use an OBD device to reset the BMS, so that it knows it has a new battery.

I installed a Duralast Platinum (AGM) from Autozone 5 years ago. No issues.

 

Funny enough, I had someone swear up and down that my car had two batteries. He said there was one in the trunk and one under the hood. He pointed at the jump terminals under the hood as his proof that there was a battery there...

 

Did he also try to convince you that he had a power station in his wall behind the power outlets?

 

I once pointed out a type on a menu to a lunch companion. It listed a "Monte Crisco" sandwich. The waiter said "No, that's not a typo. It's fried."

That made it even funnier.

 

I just replaced mine with one from Walmart at under $200, a direct replacement.
Easy to do, however as another respondent said, you must perform a battery management system update so that the car recognizes a brand new battery. Otherwise it will likely overcharge it and reduce the life.

You need a Jaguar appropriate scan tool like an iCarsoft LR V3.

A dealer will charge you $500 for the battery and another $200 (1hr labor) to install and update the BMS.

 

When using that odb scanner, have you had issues with exiting out of it correctly?

 

Yes occasionally, but a quick disconnect of the battery for 30 seconds will fix it. always double lock and check that the warning triangle light extinguishes after 15 mins to show the car has gone to sleep.

 

Thanks for the info on the scan tool. I'll check it out on Amazon.

 

I replaced the main battery about 18 months ago and then I used my iCarsoft LR V2.0 to attempt to reset the BMS but no go, it failed no matter how many times I tried.
The iCarsoft LR V2.0 definitely has the BMS reset function so my best guess is that the failure was due to the secondary (start/stop system) battery no longer being there as I removed it years ago. Despite this the battery and electrical systems have behaved perfectly ever since, I believe the BMS resets itself after a few drive cycles anyway.
Moral of the story - if you have an early F-Type with the two battery SS system and you have removed or disconnected the secondary battery then it's likely an iCarsoft scanner (and probably any scanner) will not be able to reset the BMS.