Does anyone have an idea for how long the battery should last on the F-Type on average if it isn't being driven?

I ask because I noticed the battery icon was lit on my car today when I had the car turned on but the engine was not running. I didn't get a popup warning in the info screen about low battery or anything, just the red battery indicator in the speedo. I wasn't sure if that was normal for when the car was on without the engine running or not. I couldn't find any display in the car that showed battery levels so its hard to get an idea of where it sat on total charge.

To be safe I hooked my battery tender up to the car. While charging it indicated that the car had below an 80% charge, but I don't know how far below. Its been trickle charging for the last 5-6 hours and the levels are still below 80% so I assume it was a fair ways below 80%.

In any case, I put around 50-80 miles on the car on Friday (2-3 trips, 2 of which I was driving at least 30 minutes in one go.) So it should have had a full charge when I parked it on Friday evening. I didn't get the chance to check in on the car again until around 2pm today (Sunday.) The car was locked which means the alarm was on, and I'm sure drains the battery. But my BMW is the same way, and I've gone two weeks without driving that in the past without any battery issues.

Until my lease expires on my BMW (just about three months away) I'm still using that as my primary vehicle. (I plan to get all the miles out of it that I paid for.) So the Jag is currently being driven mainly on the weekends and whenever I feel like going for a joy ride.

How fast does the battery normally drain when not in use? Is this normal, or does this suggest there may be a problem with the car (or battery?) If normal, it sounds like I should plan to keep the Jag hooked up to the battery tender through the week if I only drive on weekends.

Thanks!

 

Most cars will show the battery icon when the ignition is on but the engine isn't running. Means the battery isn't charging.

 

Most of the idiot lights will go on when the ignition is on, and the car isn't running. That's how you check to make certain the idiot lights aren't burnt out.

....Why can't we have real gauges? (or at least digital data on the infotainment system)

 

Thanks... that is nice to know... though the battery turned out to need charging either way, so its good that I checked.

Getting back to the original question, I'm still looking to know if there a sense of how long the car can sit (on average) without being started before the battery is drained or too low to start the vehicle? I'd like to make sure I avoid any issues going forward.

I read a few threads that have suggested that some have gone more than a week without starting the car and had no issues, which sounds great. Though I'm concerned that mine may not be so efficient.

 

I am aware of one 2015 R Coupe that sat idle for 5 months. Started right up without any indication of a drained battery.

 

Wow 5 months?! That doesn't sound possible to me. Particularly for a car with all the electronics this one has.

I know the car will shut down higher power draw systems and eventually shut down completely when the charge gets low enough, but I'd imagine that final battery charge would fade on its own before 5 months even without use.

Hopefully I'll never need to test that theory, but it does make me feel more secure about not charging it for a week.

 

I left for 2 weeks and no problem. I'm afraid to leave our Maserati for 2 days without the trickle attached.

 

Mine was stored without charging for 5 weeks from I bought it and till I could pick it up (F-type R).

It started without any hesitation the moment I pushed the button

 

I don't know how long the battery will last without being driven or charged, but it varies considerably. For example, cars on a dealer showroom floor are routinely dead because people are getting in and out of them, and playing with the power seats, etc. If the car is locked and left alone, the battery will hold a charge much longer.

I just got back from vacation, and my car's been idle for 10 days with no battery maintainer attached. I have a Battery Tendery Plus hardwired into the battery bus, so I plugged it in yesterday afternoon. 18 hours later, the charger indicator light is still solid red, which means it's below 80% charged (the indicator blinks red when it reaches 80% and turns green when fully charged.)

 

I am also using a Battery Tender Plus unit, though I am using the clips on the jump posts in the engine bay as I don't have the wiring harness installed on the Jag.

It sounds like these cars may discharge the battery fairly quickly to start, but once they get to a certain threshold, the power save features kick in pretty aggressively and the power drain drops significantly. So I suspect I have nothing to worry. Though I am considering no longer locking the car in the garage to avoid the additional drain from the alarm.

 

I agree you don't have much to worry about by leaving it unplugged for a few weeks.

I don't think the F-Type is much different than any other modern car with all the electronics of today. I've experimented with plugging in the Battery Tender just after driving it, and it's not even fully charged then, but is usually blinking red, which means it's above 80% charged. If I leave the car sitting just a day or so, it's below 80%, but fully charges in a couple of hours.

I don't know how low the percent charge can fall before the car fails to start, but I'm guessing it's well below 50%. I think you can safely leave it for a couple of months without a maintainer.

Now if you factor extreme cold into the equation, that's a different matter. A couple of months with temps in the teens Fº, and it would most certainly be dead.

 

Some modern cars are definitely worse than others when it comes to battery drain from lack of use. It isn't uncommon to hear stories of people coming back to a dead battery after a week or less without driving. bjg625 was saying earlier in the thread that his Maserati has issues after 2 days. So it can vary quite a bit.

Luckily I don't have to worry about that where I live. The coldest it gets here is the low 40s or high 30s. Plus I keep the car garaged, and I'm sure it stays warmer than that in the garage. When I lived in your area (I was in the NoVA area for the last couple of decades and only moved back to California 4 years ago) that was another story. I drove an SUV there, since it was all-season friendly.

 

Yep, we've traded places. I lived in Palo Alto for 10 years.

 

Rather than guesstimate how long it will last, and as no one really knows the answer, I would suggest you invest in a CTEK trickle charger or similar.

I have three other vehicles with this kind of charger and I have seen some last >12 yr. My F goes on charge at every opportunity when it is in the garage, and I expect to get 10 years + out of my battery.

 

Oddly, my car was at the dealership last week for a recall to address a battery drain. I didn't clarify if this was an electrical or physical drain though...

 

The Battery Tender (BT) Plus does exactly the same thing as the CTEK, which is what we were discussing above. With it hardwired to the battery bus, it's a simple plug in, and the trunk lid (boot for you) closes over the power cord.

You are right that lead acid batteries do not like to run down and stay healthier at full charge, so leaving it on a trickle charger/maintainer like the BT or CTEK theoretically leads to the batteries lasting longer than they would otherwise.

 

I'm planning to leave my car on the battery tender during the week anyway to be safe. But I'm less concerned about leaving it without the tender now.

 

As a follow-up to the conversation we had yesterday, it took 36 hrs for my car to reach a full charge using the Battery Tender Plus. The car had been idle and unplugged for 10 days while I was away on vacation. That's the longest it's been idle in the year I've had it.

 

Interesting. So it was obviously pretty far down on battery after 10 days. With mine just idle from Friday afternoon to Sunday afternoon, it took at least 12 hours for mine to reach a full charge using the BT.

So it seems like the car eats battery a lot faster after being recently driven, and doesn't start shutting down systems until the battery gets to a certain level (50% perhaps?) I also assume it probably shuts down completely when it gets to a critical threshold on the battery charge (25%?) which would explain how these cars can still start after weeks or months without being driven.

Out of curiosity, did you leave the car locked/alarmed while you were gone? If so, was the remote still usable to open the car when you returned? (Would suggest the radio for that was still being powered.) Otherwise, did you notice anything else that might suggest that the system had completely powered down due to being idle so long?

 

Yes, the car was locked for the entire 10 day period with the fobs inside the house. I did use the remote to unlock the trunk to plug in the BT. The red LED (indicating alarm armed) was blinking, so it was not completely powered down.