Since I've noticed all the posts about the problems that a discharged battery causes in the F-Type, I installed a Battery Tender and use it if the car's not going to be driven for a few days. (That is actually a rare occurrence.)

I noticed that the first time I used the Battery Tender, it took almost 24 hours for it to register as fully charged...

Fast forward to this week... After not having driven the car for about 3 days, all the while being plugged into the battery tender, I get in to start the car, and I get the "Battery Low please start car" message... Strange... It's been plugged in for nearly 3 days...

I drive the car all day long, come home and plug it back in, assuming the Battery Tender to register a full charge, but no, it starts charging immediately after plugging it in. 24 hours later it's still charging...

Now I'm curious and I remove the Battery Tender (after 24 hours) and attach a real battery charger. The charger gauge shows the battery is sucking up 8 amps... I leave the charger on for an hour before deciding to take it off, since Jaguar doesn't recommend charging a battery while in the car.

I've never actually experienced a Problem, other than the displayed warning, but I am beginning to wonder if the battery is defective and isn't holding a charge.

Any similar issues or recommendations, other than, "take it to the dealer"... (which I will do if I actually experience a problem, or at the time of my first service...)

 

The 24 hrs to charge on a BT is normal even if you plug in immediately after driving a good distance.

The warning message is the only strange part. Do you have it wired per these instructions, which came from Jaguar? It's not likely, but I'm wondering if an alternate wiring scheme could throw a warning even though the BT is showing normal charge indications. Didn't you say you wired yours a bit differently?



Nookieman gave me the idea to put a 12v charging port voltmeter ($5 on Amazon) on the car. I've been observing it lately and the readings vary greatly depending upon whether I've had a BT hooked up or not.

After a full BT charge with the car at rest, it registers 12.6-.7, and when started, it drops down to the low 12s, with occasional spikes in the 13s as its driven. Once you drive it 20 miles or so, the voltage numbers start creeping up to the higher 12s, and you see more spikes in the high 13s to above 14v.

If I don't put the BT on for several days, the resting voltage is a little lower (12.5 usually), but when the car is started, it almost immediately starts registering voltage numbers in the high 12s to 13s with occasional spikes above 14v. I drove the car last week for 5 days in a row and 60 miles per day, did not put the BT on at night, and it showed these numbers everyday.

After putting the BT back on immediately after getting home from work on Friday night, it took 26 hours to charge, and when I drove it today, it went back to the low numbers in para 2 above.

What that seems to indicate is when the car starts with a topped-off battery, the software tells the alternator to rest, and when started with a partially depleted battery, it's charging far more often. However, the alternator never seems to fully top off the battery, which is interesting.

I don't see any reason to plug in the BT unless it's going to be idle for a couple of weeks or more.

 

Which BT are you using and is your car single battery (I assume so from your picture) or does it have an Aux battery?

 

Mines a 2016 with a single battery. I did wire it a little bit differently, but knowing a little about electricity it makes no difference. I just put the positive at a different point on the bus bar. This makes NO difference as the bar is one solid piece of conductive metal and any attachment to it will do the exact same thing. I just chose a different point to give me more length for my pigtail.

I have the standard Deltran "Battery Tender" from Amazon.

 

I would add that my car had some weird codes that went away with a new battery. The new battery was installed last month.

The old battery tested fine but clearly wasn't fine. I also got a transfer module reflash at the same service as the new battery. All is well now. Thee battery was $391 at the dealer.

Interestingly, the Jaguar tech recommended installing the ctek tender directly on the battery terminals to protect the transfer module instead of per jag's instructions. I chalked that recommendation up to ignorance and left it installed per Foosh's pic.

I think it is always a good idea to put in a new battery if the car is acting up. The forum is full of battery related issues, on all the newer models. I plan to do it every year. if that is all it takes to make the car happy so be it.

 

I have had lots of those messages over the time I have had my car, I don't have a battery tender but I did once need to leave it at the dealer overnight for them to use their deep cycle charger to revive the battery, haven't had an issue since then.

 

In the cars with 2 batteries, the BT needs to be connected to the BUS bar to supply both batteries with a charge. In the 2016's It shouldn't be a problem to attach it directly to the battery terminals.

 

From what I read, while the 2016 doesn't have the second battery to worry about, it is still a bad idea to attach directly to the battery terminals as it can cause problems with the battery level monitoring circuit. That is why I attached mine to the electrical bus rather than direct to the battery. I have no personal knowledge of this, I'm just parroting what I read.

 

That should be true, and I did it that way initially without an issue. It's been so long I'd forgotten that the primary reason to wire it to the buss is to charge the 2 batteries in 14-15 models, so I switched it over. However, as Merlin said, I've also seen it reported by seemingly-informed sources here that it could interfere with the "battery level monitoring circuit" whatever that is.

And just for the record, the wiring on my car in the picture above came from instructions provided by Jaguar in 2014 to dealers on how to wire a CTEK-manufacturered, Jaguar-branded, battery maintainer sold as an optional accessory (for way too much money) by Jaguar in dealer parts departments. It's no longer offered.

 

For the record, I do have the positive connected to the BUS bar and the negative on the earth ground. I also read not to connect it directly to the battery terminals.

Quite strange that Jaguar no longer offers the CTEK charger...

 

Thanks for the details on your setup. My main concern here was that the charger you were using, may not have suited the AGM batteries, which must be charged at no more than 14.8V otherwise damage will occur internally.

That said, I see the specs say that it can accommodate AGM's, so that should not have caused any issue.

It is prudent to follow the connection procedure as per the spec, as the Battery Monitoring Module (Mounted on the -ve post) will be incorrectly be seeing/monitoring the charger state, INSTEAD of monitoring the battery state, IF the BT was connected directly to the battery.
Connecting the +ve, as you have done, ANYWHERE on the busbar is fine of course.

At the point you're at, I would run it back to the workshop to see if you have any fault codes logged.

 

Tel, I also have a code scanner. No codes... I need to look if I can pull voltage from the scanner I use too. Might tell me something.

Again, I haven't really had an issue that's caused me a problem, just seems to be strange and I wouldnt want to be left waiting for a jump or roadside assistance one evevening should the battery or charging system be a problem.

 

I'm starting to notice this problem as well. If I don't drive the car for 1 or 2 days I get the low battery, please start car. I usually pop the trunk before I get in, so when it doesn't open I know the battery is low and it tells me to start the car first

 

The battery was HOW MUCH!?!

 

That's really not much more than I was expecting, although I still don't LIKE it. Optima AGM Batteries from AutoZone run an average of $225...

Now, consider this is from a dealer, and it says on the battery that it's made in Italy... $391 sounds about what I'd expect from a dealer.

 

Good lord. This isn't even close to acceptable. It seems like this may be less a problem with the car and more of a problem with shitty batteries being used.

I can think of no better way to wind up in divorce proceedings than to tell my wife that I have to plug in my $100k car every night like an iPhone.

 

Yep, I have a 14, and the positive is connected to the bus bar. Still, less than two weeks ago a Jag tech suggested it was better to go directly to the battery. Made no sense to me so I ignored him.

 

$391.00 USD. For one, installed. It's only about double the street price. I figured they would install it correctly and the car would not need any tweaking so that was worth something. Of course they still screwed it up. I had to reset the windows, reprogram the seats etc. I guess next time I will do it myself. The window issue caused problems with the smart top module but it's all good now.

 

I haven't had this problem myself, but I agree it is a pretty lame situation that we shouldn't have to worry about. I suspect it is probably the result of either a bad batch of batteries or a charging issue, or at least I hope it is, since replacing a battery or alternator isn't too tough.

Personally, I just keep mine plugged into the BT all the time when I'm not driving it since it helps extend battery life as well. I ended up doing a hardwire install using the ring terminal harness to make it simpler... so now after I park I just open the trunk and connect the BT to the plug before I leave the garage.

As long as I don't forget to unplug it before leaving the garage I should be fine.

 

Just out of curiosity, how long does it take for the BT to show a full charge after you plug it in?