"Low Battery - Please Start Engine"
 

I'm getting this warning (page 172 of the 2016 owners manula).

The manual says to drive for 30 minutes to recharge. So, I have...THREE TIMES THIS WEEK.

Battery and alternator checked yesterday and they are fine...but don't we have two batteries? I suspect the guy (spontaneous stop at local shop) only checked one.

This appears to be tied into accessory support (like monitoring systems and even remote trunk opening). Which battery drives that?

Do a search. This is a known issue that results in 2014-2016 after the OBD port is accessed. You need to reset the car's energy management system by disconnecting the battery for a few seconds. After that, your battery should hold a charge normally.

You can confirm the diagnosis if your red hazard triangle doesn't turn off after locking the car and letting it sit for 5 minutes.

Although this worked for me a few times, it was not a permanent solution as the battery kept dying a few days later.

As far as I know, they have not fixed this and refuse to recognize it as an issue, as the dealer could not "reproduce" the problem.

If the energy management module reboot does not permanently fix the issue (at least until the next OBD tap), then the battery might not be able to hold a charge anymore, in which case you'll need a new one.

SWMBO's beemer does this every once in a while. Rather than driving it around, I attach a battery tender overnight. No real pattern as to when or why the warning will appear, at least that I can see.

I don't know about them not acknowledging it as an issue...they gave it space in the owner's manual

Unplug the battery, hold the brake pedal for 30 seconds and then leave the battery disconnected for 10 minutes. Works for me every time I access the OBD port.

What does the brake pedal have to do with this issue?

Larry

Modern cars have all sorts of capacitors and other small power storage devices in various modules to keep memory stored when the battery is disconnected. When you're trying to do a hard reset by unplugging the battery, pressing the brakes will drain remaining stored energy from those modules because the car tries to light the tail lamps.

This is why a quick 5 second disconnect of the battery doesn't always reset the energy management module. It still has power for a short while stored in the unit. A quick press of the brake pedal and 10 minutes unplugged as always worked for me.

I had this issue, a new battery and reset fixed the issue.

Yes we do have two batteries. The little motorcycle looking battery in the trunk is to restart the car after stopping if you don't hit the "Intelligent Stop/Start" button. I just disconnected mine with no issues. Now I don't have to hit the button to prevent the car from shutting off in traffic.

Lookout's 2016 V6S only has the big battery.

Disconnecting batteries
 

Hi,
Old thread. I have this issue on a used 2017 F-Type I bought last week. It complained about low battery for a week but worked fine. Drove it every day except for a gap of two days and the battery was completely flat. I jumped the car. I noticed that the warning light stays on so I'd like to try the disconnect trick. But my question is, do I disconnect both batteries on only the one in the front? The one in the front looked like it was connected a little strangely so maybe there's an odd procedure?

Many thanks,
Dave

Dont leave lights on auto and windscreen washer stalk both should be Off known battery draining points on older jags . these cars were made in Birmingham :icon_smash:

I think I answered this myself. Looks like there is only one battery on my car, in the back. I disconnected it and so we'll see whether that fixes it.

Yep, only one battery on a 2017 model.
Get yourself a decent battery tender/maintainer (several around here use CTEK) and hook it up whenever you expect to go a day or more without using the car.

I just fired up the beast for a long drive after letting it sit for close to five weeks (trapped behind a bunch of remodeling building materials. No issue starting, no low battery warning and no tender applied during the hiatus. The parasitic drain on these cars, once they shut themselves down properly, is negligible. The real issue is to make certain the battery management system is working properly after maintenance has been done on the car and to reset with a battery disconnect if it isn’t.

As they say in the classics, YMMV!
From all my reading here and on other Jag forums it seems there is little rhyme or reason as to when, why or how you will have battery low charge problems.
All I know is I have been hooking up my battery tender to my original now five year old battery once a fortnight or so and I have never had a single battery or electrical system problem. And I hardly ever take the car for a long run, the most I see for months even years is about 20 miles at a pop, and I haven't disconnected or reset the battery for well over two years now.
For the sake of around $200 outlay on a decent battery tender and five minutes effort once a fortnight I reckon it is good insurance, even if it turns out I am wasting my time and money!

Edit - forgot to add - I have used the VAP tool plugged into the OBD2 port 5 or 6 times now, an iCarsoft i930 and then the LR v2.0 dozens of times and an elm327 plug to run Torque several times, and never once had a battery problem.

I got real annoyed with the OBD problem, and couldn't find a OBD reader that the car would acknowledge for shutting the car off. Added a quick battery disconnect switch on the terminal, works fine so far.

The procedure described worked great. I simply disconnected the terminals on my (single) rear battery. Pumped the brake pedal and waited 10 minutes before reconnecting (red first). Then, I reset the time and date and moved the side windows up and down a couple of times. I started the car and let it idle for 2 minutes, then put it in drive while depressing the brake for 2 minutes, then went for a 20 minute drive in "mixed conditions" which I felt was the reward for all this arcane stuff that you should never really have to do....

No problems since and no repeat of the dreaded message.
Thanks for your help forum mates.