Hi!
I own a 2021 Defender and I only drive it a few months a year since I live between the east coast and west coast. I would like to purchase a trickle charger but not sure which one to get. I saw online that my car has two batteries, is one of them lithium?
I'm between purchasing the CTEK MXS 5.0 and CTEK CS FREE 4 in 1 that apparently works with lithium batteries as well. any idea what's the best for my car? it's mainly to maintain the battery but would also use it if I had to charge the battery eventually.
Last, will I have to connect the trickle charger to the battery under the passenger seat or the battery under the trunk?
thanks in advance for your help.
Best,
Olivier

 

You should connect the trickle charger to the battery terminals under the hood. The lithium battery under the trunk is the battery for the 48v MHEV system, which is used to support the engine. It replaces the accessories with an integrated starter-generator to help improve fuel economy, give a slight power boost at low RPMs and offers nearly instantaneous auto stop/start. It is charged with the energy recovered under braking and does not require external charging. The standard 12v battery under the seat powers the infotainment system, interior electronics, accessories etc. and should be on a trickle charger if you're storing your car long-term. Like I said, connect the charger to the battery terminals, which I have attached a photo below.

 

Well noted with thanks. Do you know what kind of battery is under the hood? is it a regular 12V and what about the amps? also, any of the 2 chargers I mentioned that seems good to you? Apparently some people are using the CTEK MXS 5.0 but want to make sure it's correct before purchasing it.
thank you!

 

It is a 12v battery with 850 amps and 95 amp hours. The CTEK is a popular choice, many in the Porsche community use that trickle charger.

 

I use a CTEK MUS 4.3 POLAR (https://smartercharger.com/collectio...-mus-4-3-polar), as our Defender sits outside and we get semi-cold winters. Works well.

 

I switched from the Ctek mxs5 to the NoCo genius 5 - I like the NoCo more
The Defender uses an AGM battery.

 

Is this the same for the P525 motors that aren't MHEV? I just bought a trickle charger and haven't hooked up it up yet.

 

The P300 and P525 use the same method as the P400/D200/D250/D300/D350 MHEVs - use the terminals under the hood. All JLR products are like this, as none have the battery in the engine bay.

 

Thanks man!

 

I'm in the same situation @OlivierLA75 . I have a place that I visit infrequently where the Defender now resides. Sometimes I'm there every week. Sometimes one of my kids swings by to stay. Sometimes I'm there for a long time. Sometimes I'm gone and I won't dare give the keys to my kids. Regardless, the first time it was left for several weeks, the battery was cold hard dead. Not only that but the little pita telematics battery had died too. Could not restore the battery and had to replace it which was quite the pita. Yes, I double locked the doors thinking it would be fine. My bad. This thing doesn't like to be lonely.

So, I put in my trusty CTEK 5.0. Since then, no problems. No matter how long/short the duration, it fires right up. I plug it to the connection points described above under the hood and then close the hood. I am absolutely going to install a dedicated connection point. There are many threads on this. My favorite is someone who ran it to the back bumper. This is likely me over the holidays. I'll add the link later if I have time to hunt it down.

Good luck with yours.

EDIT: Here's the thread - Link
It has all the classics. @Dogpilot with a solar mount (didn't work for me because it's in a barn)
@gurka01 with a EXCELLENT magnet mount. I'm a pass because I'm cheap.
@WTFChuck and/or @R-dubb did the classic CTEK mount at the back that I'm going for and would recommend.
Again, good luck and post pics/details afterwards of your solution!