I'm hoping someone has some experience to help me figure out this recurring problem because the local "expert" dealership mechanics can't figure it out or, more likely, are not interested in figuring it out. So, I bring my car for service and when I pick it up it says "Low Battery Start your Car." I go inside and ask what they did to kill my battery and they said they probably just had the door open while they were servicing it too long etc and so on. OK fine, that was about a year ago and it was the original battery so (Car is 2016) so I don't think much of it. Drive the car a few times over through the year, no issues, starts right up. Let it sit for a little longer than normal earlier this year and the battery was dead. Jumped it and took it to the dealership for a new one. Dealer says they have to check everything (So they can charge me for it) and reports back that everything was good, alternator is fine and system seems good and I just need a new battery to the tune of $700. Play expensive games win expensive prizes. Drive the car home park it in the garage. Now I add the insurance company plug in to get a discount on my mileage. Go out 2 (Two) days later and its dead. Completely dead not sort of dead. Odd, because my 15 year old car with mystery age battery can handle the billionth of an amp draw from the insurance dongle, but the Jag can't? Call the dealership back. "We're so sorry must have been a defective battery." Bring it back to the dealership. They swap batteries allegedly. I bring the car home park it in the garage and one week later...dead again. Call the dealership, bring it back. After a week they tell me the insurance dongle is not letting the car "go to sleep" and must be draining the battery. Whatever, take the dongle out and bring it home. All is good no more dongle. 3 days later...dead. Back to the dealership, seriously, and after another week they tell me everything checks out ok and they have no idea whats wrong and the car starts just fine. So what can I do? Nothing but pick it up. Drive it home. 3 days later and it works! I take it to DMV to get it inspected no problems. Go home park it and 4 days later...dead again. I'm bringing it back this week.
Does anyone have any clue why batteries would keep getting shot like this. They claim my alternator is good and they have checked it 3 times now and I'm sure they'd be happy to charge me for a new one since the car is now out of warranty. I read somewhere that there are 2 batteries in the 2016s, one for starts and the main one. Is that true? But when I say the car is dead, its dead. Not even the LED dome lights come on. Plus it takes a long time charging it off my truck to even get it to try to start. Is there some relay that gets smoked after too many low voltage events or something? The dealership seems to have no interest in fixing this but if I bring it to another one I just don't want to go through the same disaster. Assuming they actually changed my original battery, I cannot believe I got 3 bad batteries in a row. There is nothing plugged into the car to draw power. For the first 4 years we had the car, I could let it sit for two months or more with no battery tender (I know not the best idea) and it would start with no issues. Since the original battery died, it will not last for more than a few days before it is dead again. Any thoughts or suggestions would be greatly appreciated.

 

First, your battery is 4 years old, and this in itself is a risk factor. Second, the battery has been drawn down to "dead" status several times - this irrevocably damages the battery. Third, the insurance dongle: ( the question of why you would want an insurance company to track your driving is a separate matter): it is obviously correct that this dongle while plugged in kept systems alive in the car - this is a known issue although it is not universal.

There is nothing for your dealership to fix. There is likely nothing at all wrong with your car.
what to do: Get a new FULLY CHARGED battery installed (and new batteries are almost never fully charged); do not plug things into the OBDII port unless you are prepared each time to do a "hard reset" (which means disconnecting the negative battery lead from the trunk floor for 30 seconds or so and reconnecting). You can easily tell if the systems have shut down: with the car LOCKED, does the red emergency light triangle on the console remain illuminated after 15 minutes or so? If it does remain lit then systems in the car are NOT shut down and the result will be a dead battery. Perform the hard reset (easy to do, but a nuisance).

And, for the record, if you have a proper battery maintainer like the CTEK units (and there are other good ones), they can be left connected for many months, in fact, indefinitely, with no damage at all to the electrical system, but with the assurance that the battery will be fully charged always. This in itself prolongs battery life immensely.

You can tell if your car has the two-battery system by simply lifting the trunk floor panels and taking a look. The main battery sits to the left and if you have the second stop/start battery, it is small and is on the right side of the trunk cavity. The negative ground point mentioned above is also easy to see. Just follow the negative battery lead the the approximate horizontal centre of the trunk floor where it is attached to a threaded stud.
There is nothing in your story which suggests any fault with the F-Type. Modern cars have enormous power needs so they require a different protocol than we are used to. What was normal in the year 2000 with regard to battery and electrical system care no longer applies.

 

I have a new to me ‘16 that started showing the low voltage message a week after we brought it home.
Checked the battery with my boss’s fancy battery tester that does AGM and it’s fine.
If I drive it a bit, I get the same message right away. If I drive it an hour or so, no message until the next morning.
Took car to dealership for it’s first, to me, check up and “it’s a bad battery”.
New battery under warranty and a BMM reset. They told me it would have been $300+.
Two days later, low voltage message.
It’s going back to dealership in a week. The car certainly doesn’t act like it’s low voltage but I don’t know how many volts is “low” enough to have the battery management module throw a code.

 

There is one thing that owners have to accept: the modules in these cars need fully battery voltage all the time . They do not like anything less, although the engine will always start except in cases of a very badly discharged battery. You have had a new battery installed but unless the new battery was fully charged before installation, and unless you use the car regularly and for trips of a decent length, it may never get to full charge!
Do you lock the car when it is not in use? Is the red flasher triangle on the console lit beyond 15 minutes after the car is locked? (If it remains lit, you need to perform a hard reset -disconnecting the negative lead for 30 seconds or so and then reconnecting). Taking it to your dealer may prove to be a waste of time unless you hve ensured that the battery is fully charged. Do you have a battery minder such as a CTEK unit?

 

Are you plugging anything into the OBD socket?

 

The battery management is VERY conservative. Both you and the OP should disconnect the battery negative (as in Post 2) and go for a long drive (30 to 45 minutes at typical speeds).
X2 except that the need to reset annoying.

 

Reconnect before the drive!

 

Thank you for taking the time to reply sov211. I perhaps didn't make it clear that according to the dealership, I had 2 new batteries installed in my car. Its about an hour and a half from the dealer to my house and perhaps not enough to fully charge a battery, but seems respectable. Presumably the battery they took off the shelf, after who knows how long, was good enough to start the car at the dealership, I'd think an hour and a half trip would recharge it after a start. That I got 4 years out of my original battery is noteworthy, but that battery stopped being the problem when they took it out and replaced it on my first trip. As to the insurance dongle, it tracks only the mileage driven and discounts my policy since I don't drive the car daily and don't put much mileage on it. You should look into it, might save you some money. The point of mentioning the dongle was that it wasn't involved in the original battery going dead because I didn't have it then, and if it was involved in the first new battery going dead, it was removed before the second new battery went dead and therefore couldn't be the cause of the second new battery going dead. I'll have to watch for read traingle staying on after the car is shut off. So the last go round, it actually got me home from the dealership, sat a few days, and then got me a day out doing errands, then sat for a few more days and then died. Are these new batteries that finicky? One would expect the battery to be charged sufficiently since it was performing just fine for about 6 trips over the course of a week before suddenly deciding to die.
Anyway, thank you for the info.

 

Please trust this: your new battey was not fully charged and probably never reached full charge. The very best thing you can do is to buy a CTEK battery maintainer, (or other reliable maintainer which has an AGM battery programme) attach it permanently to the battery system (very, very easy and there are multiple threads on this). Allow it to bring the battery to full charge - this can take up to 24 hours or more. Now you know that the battery is fully charged; you will find that the issues have disappeared (and if keep the unit plugged in when the car is not actually in use, the issues will not reappear).
Thanks for providing the additional information, but there is nothing there that makes either the assessment of the problem or the advice change.
I wrote you a much longer note but it disappeared before posting. Anyway, given the history, the overwhelming probability is that *there is nothing wrong with your car*.
Adding anything (like the insurance company dongle) to the OBDII port is a bit of a risk unless you monitor the car afterward (to make sure it shuts the systems down properly - red triangle is the proof) and are prepared to do a "hard reset" by disconnecting the negative battery lead. You might want to do that now, and charge the battery...
Can you let us know how things go from here?

 

Such a stickler for the details!

 

Thank you once again for the reply. Full disclosure, what I don't know about cars could fill a warehouse, but I think I was spoiled by the factory battery. As I said, it lasted a solid 4 years with no tender during the winters, when the car was not driven to avoid the salt and brine of New Jersey's spectacular road network and with sporadic trips at all other times of the year. The key will be to see if the dealership will warranty me yet another new battery. If so, I will bring it directly home and put it on CTEK tender. One last question if you're willing...I read somewhere that the new batteries have to be programmed when they are put it in the car. Is that the case or can I go just buy an OEM battery and swap it myself. The only reason I keep going to the dealership is because I was under the impression they had to be somehow programmed to the car.
Thanks once again

 

Muuuch cheaper and easier just to buy a new battery and install it yourself.
It doesn't have to be "programmed" to the car (ie the Battery Management System or BMS reset), the system will reset itself after a few drive cycles, this is just a con by dealerships to get you to bring the car in and buy a new battery from them and have them fit it and "program" it and pay through the nose for the privilege.
The main thing with fitting a new battery yourself as sov211 has pointed out is make sure it is fully charged BEFORE you fit it.

 

Folks here say that, while dealer reprogramming new batteries is the best, they WILL eventually 'come around' without further encouragement. Several owners here have replaced batteries themselves.

But to repeat, you DO want them to be fully charged. Here is the chart to show % of charge for the AGM batteries used:

 

Another option is to do the BMS reset yourself, there are a few later generation OBD2 tools / code readers that can do this such as the iCarsoft LR V2.0.
I have one and it works great, but be warned the earlier iCarsoft i930 (which I also have) does not have this function.
As a new F-Type owner I strongly recommend you get a decent code reader such as the iCarsoft as it can and usually will save you heaps of time money and angst trying to track down and fix problems.

 

I can concur that the iCarsoft LR V2.0 is a great reader that has never caused me the OBDII battery drain issue. But, as others have said, any and every time you plug anything into the OBDII, disconnect the negative battery cable afterwards to reset it and prevent battery drain. I have a '14 V8S that is still running on the original battery. But now that I've said it aloud, it'll probably die. Damn it. It's not a fault with the batteries, nor the charging system, just a well known (to those that read every thread on here!) issue with plugging into the OBDII.

 

Yup, same here, the LR V2.0 has never caused me any battery problem (in fact I have never had a single battery problem ever) and I'm still on the original now 6+ years old battery.

 

Oh, and definitely never leave anything plugged into the OBDII, especially an insurance dongle.

 

I'm on original battery for 6.5 years. I put it on CTEK when we used to travel. Only use of OBD is smog check once a year. Low mileage but don't know if that matters. The second battery has been dead for 3 years after being replaced once.

 

Drove it a couple hours yesterday.
Checked voltage this morning, 12 volts. No low voltage message. Red triangle was on.
Ran to the grocery and checked the voltage, while running, when I got back, 14.87 volts.
Turned off and watch the voltage drop from 12.8 to 12.5 rather quickly.
Pulled the rest of the trunk apart and disconnected the NEG. Notice new battery was Mexican. Not that there's anything wrong with that.
I'm not buying the whole "nothing wrong" routine. If this thing runs at 14.87 volts, how is the battery not fully charged after two weeks of driving?
If I have to monitor the car for a red triangle every day and pull the ground if it's there... It's 21 degrees outside.
Remember, the dealer just reset the BMS and did a hard reset. I had to change all the display options back to the way I like it.
If I have to put in a battery minder because we drive it every other day... Not that it's a big deal, we're NOCO dealers, a Genius 2D will cost me next to nothing, but still.

 

Thank you for the reply, much appreciated.