Low Battery warning

(68 E-Type) #1

My 2016 F-Type started showing the “Low Battery - Start Engine” light. Took it to dealer and they replaced the battery, (as well as fuel tank cap (unrelated) due to check engine light.)

The low battery light has come on again. If I drive it for 30 minutes or so, it is good until next morning. Drive it for a few minutes - comes on when I get back in car.

Anyone have similar problems?


2 things here, either you have a drain on the battery or you are simply not driving the car enough.

Fully charge the battery overnight if possible and then see how long it takes for the warning to come back.

(68 E-Type) #3

Two good thoughts. The dealer installed a new battery two weeks ago. I am inclined to believe there is a drain on the battery. I drive it daily, but only about 15 miles. Drove it today about 80 miles, mostly interstate, keeping fingers crossed for morning.
I have an appointment at the dealer for an “evap" check engine light and added this to the request. I read on a forum (can’t remember which) that there is a secondary Lithium-Ion battery that is used for starting. Perhaps it is bad? I will ask about that.

Preston Garner

317 Woodberry Dr.

Chesapeake, VA 23322-5739


757-650-9832 ©

757-547-2801 (H)

“Still plays with cars, especially little British ones!”


Most F-Types have a pretty weak charging cycle. If you don’t drive long distances, the battery fades and will eventually die from chronic operation in a low voltage state. The answer at that point is a new battery. But… many new batteries sit on the shelf for a while, so they too may be in a pretty low charge state when installed. In most cars, that would get remedied upon the first solid drive, but in the F-Type, a partially charged new battery can fall into the same low voltage rut.

The problem is exacerbated by Jag’s selection of a high quality AGM style battery, which operates at a little higher voltage than Lead Acid. AGM’s are notoriously very finicky to slow-charge once significantly depleted, and even if new condition, they may fail to accept a low amperage charge.

Obviously this isn’t a great dynamic for the Jag’s low amp charging circuitry. So it is important to fully charge a new AGM battery upon Jag installation–your dealer probably did not do that because, sadly, they really don’t know much about F-Types.

Recommendation: disconnect your new battery from the car and charge it manually to 100%. After that it will likely function just fine. The owners manual recommends physically removing the battery from the car before charging it out of an abundance of caution.

You will need an AGM capable charger that outputs at least 5A to get your new battery back up to 100%. You will probably find that 3A or less “hangs” during charging and the terminals may get a bit hot. The solution is to apply 5A to10A to an AGM in the 1000 CCA range, like ours. It is worth investing in a decent charger with a percent-charge readout, so you can verify and monitor AGM progress to 100%.

Good luck! I think your F-Type + AGM is displaying normal behavior.

(68 E-Type) #5

Interesting! A little disconcerting to get in every morning with that warning staring at me!
I figured it was time to upgrade my 40 year old battery charger!
(Removing the battery will be fun)

(Gunnar Helliesen) #6

I had the same problem when my car was about a year old. The dealer replaced the battery and I never saw the light again. Knock on wood.


(68 E-Type) #7

Well, it has been awhile now. I took the car into the dealership for an unrelated problem. (Even after I charged the battery, the light still came on.) Discussed with service rep and he said that it was due to the insurance company monitor I had in. (That is one of those 90 day devices that plug into the OBD port.) Well, I was skeptical, especially after discussing with the insurance company. (Still received a 12% discount) I unplugged it and returned to the insurance company. It has been three weeks and no light. My take away is the device was at fault. Sounds crazy, but everything has worked perfectly since then.

(Gunnar Helliesen) #8

That’s interesting. I had a problem where my transmission would refuse to shift out of Park if I turned the car off and then immediately turned it back on again. I’d get a “Transmission Fault” yellow triangle on the dashboard display. The fix would be to turn the car off, wait at least 1 minute, then turn it back on again.

I had the dealership look at it multiple times, but they couldn’t find anything. They upgraded the software in the engine and transmission control modules, but it didn’t help. Finally they suggested I unplug my ODBII device* and leave it unplugged. Lo and behold, that seems to have done it. No problems since.

*) Not for insurance, but one of those gadgets that’ll help you record each trip you drive, and which also supplies diagnostic data via BlueTooth for apps on your smartphone. Very cool.


(Paul Wigton) #9

Would it be impertinent of me to ask, WTH is that???

(Andrew Waugh) #10

It’s an electrical connector, usually near the driver’s left knee. It’s a bit like the old Centronics connectors for printers, just fewer contacts.

( :slight_smile: )

(Paul Wigton) #11

Right, ya smartass.