I am a new member and owner of a 2018 LC. I need to put on the trickle charger. So I connected the trickle charger to my rear battery terminal in the trunk (positive to battery; negative to body ground), but after 4 hours, the charger light still is red, indiicating the battery is still charging. I have been using a trickle charger for 15 years on my summer car, and usually the battery charges full green in 5-10 minutes on my cars, and maintains the charge throughout the winter. I am obviously doing something wrong. I looked in the manual and it was of no help. Can someone help me out here? I looked on You-tube and there was a video on jump starting the LC. It showed connecting the charger to the fuse box in the front (???!!!). Never heard of such a thing, and did not attempt. This is my first winter w the LC, and I want to keep the battery charged while the car is stored in my garage. Thanks!

 

How long it takes to trickle charge really depends on the charger itself. I use a noco genius on my cars, and it usually takes a few hours to get to 100%.


As far as jump starting the car from the front, that is normal for modern cars with the battery in the trunk. There is a tab inside the fuse box that you can open and it leads directly to the battery. Something you have to remember when using the tab is that only 1 side has a metal contact, so when clamping jumper wires, the side with the wire has to touch the side with the metal tab.

 

I have my maintainer/charger permanently and directly connected to the positive and negative battery terminals and simply connect it to a power supply when and as I think it may be necessary.
In regards charging time then the maximum output from the charger is 3.8 amps/hr and therefore if you have say a 70 amp/hr battery then to charge from fully flat will take 70/3.8 = 18 hours. In practice my maintainer tells me how much charge is left in the battery and it is usually anything from 50 to 75% and therefore a proportional reduction in the charge time. Certainly isn't unusual to see the battery take 8+ hours to fully charge, especially if I haven't driven the car for a week or two.

 

wow really? i would never have considered that a battery would drain that much sitting for a week or two.

i've definitely not driven my car for 2+ wks and never had any issue starting (no trickle charger here).

 

If you have a healthy battery, then the car should still fire back up after 2 weeks. I've only ran into issues with cars not starting when sitting for like 6+ weeks off a charger, but even then all the electronics will work. The car just needs an extra boost to turn over.

 

I don't know what it is with modern cars but they do seem to passively draw much more current than in times past. I guess also living in a cooler climate doesn't help and nothing sees off an ailing/old battery quicker than a few days of frosty mornings.

 

+1 for ^^^ this. I wired a CTEK charging dongle directly to my positive / negative battery terminals in the trunk, and when I need to charge the car I just connect my CTEK charger to that dongle.

To the OP, if your charger is still showing red it's probably your ground connection. Go straight to the battery.

 

Hi JBuffet,

Can you post a pic of what that dongle looks like in the trunk? Thanks!

 

^^^^

 

Hi Guys,

I thought I'd revive this thread since we now have the 2024 models, and the fuse box layout seems to be different (maybe not). I have a 2024 Bespoke Convertible. I am trying to figure out a way to permenantly install a trickle charger 'ring terminals' into the fuse box area. Within the fuse box, there seems to be 4 possible connection points for hte ring terminals, but I'm not sure which ones. There are 2 bolts in the box that seems to be connected, and 2 others which seem to be independent of one another. I am also thinking that at least one of the bolts maybe there to hold the fuse box in it's place within the engine bay. Does anyone know which of these bolts maybe used as a positive terminal to trick charge / jump start? I am fully aware of where the physical battery is, and also aware that there is positive 'tab' which can be used to connect an alligator connector. The goal here is to permenantly install a 'ring' terminal onto one of the bolt. I've checked everywhere in the manual, but there is no mention of this at all anywhere.

In the previous models, There was a separate box within the fuse panel wich you remove to expose the bolts. It seems that the newer models just has them exposed. I just don't know which one I need to use to install the terminal. Any help would be appreciate it! Please see the attached pic. I've marked 3 possibilities and labeled them 1, 2, and 3. Which one is he positive terminal bolt?

 

Why don't you make life far simpler for yourself and wire up direct to the battery?

 

I thought the same direct wire to the battery might be the best way to go. But one problem exists for me is I would have to add a bit of wire to the leads so the quick connect plug is up at a high point so taking things in and out of the trunk don't snag the wires of the charger and making it easier for my wife to unplg/plug the charger. asong1, I don't know the answer to the question you asked, but I did check and all the terminals you highlighted have 12v to ground. Also you would have to drill a hole thru the wall of the fuse box, as there is no access to the fuse box due to it's design. Hopefully someone has some who has done this will chime in as I will need to do the same soon. I am willing to do a little up front work to minimize effort later. Plus I like the quick connect plug vs the clips just incase someone bumps the cord while walking thru the garage and having the clips come off and causing a bigger problem.

 

I don't have an LC yet (just made an offer on one, though), but if I get one, I'd put a pigtail to charge it right away as well. On the picture above, I'd put the '+' lead on #3... assuming I could put the fuse lid back in place without modification. Like feeding the lead underneath, if necessary. In other words, fully reversible. By the way, where is the battery on this car? In the trunk? If yes, then I'd put the pigtail under the hood, probably using that #3 nut. Equally important is using a proper ground, for proper charging. I don't like not using the battery directly, but being in the trunk, there's no way around that for me. But smart chargers don't like that, for some reason, showing the battery as discharged when left connected for a while. At least that happens with both the G70 and Macan (both with batteries in the trunk/hatch). But if you just charge it, and disconnect it within a few days, zero issues. By the way, I might elect to buy an extension, to put the pigtail by the hood hinge, on the outside, so it's not necessary to open the hood, like I did with my ex-Porsche. But I always like to open the hood, especially in summer, so I'll have to decide when I see how I could route it. And how easy is to open the hood; on some cars it's quite hard, so I'd probably opt for the outside hinge location, if that's the case.

 

I just lift up the rectangular red lid with the + on top of it, inside the fuse box area.
I then attach my positive cable to the metal tab on the now exposed remote charging terminal .
Place your negative cable on a bolt on the strut tower to act as a ground.
Never had any issues and car charges up quickly with a battery tender.

 

Do you leave the trunk open when charging or do you close the trunk lid? I need to store the car for the winter and just wanted to know if closing the lid would hurt anything like the trunk seals.
Thank you