I just got a 2016 4 GTS a few months ago. The previous owner gave me the CTEK MXS 5.0 that he used as part of the car sale. I'd like to start using it since I've been traveling for work and could go a week or two without driving. Two questions...
1) For this model year, do I use the AGM option?
2) The car already had the connections to the battery for the MXS which are on the left side of the frunk. My outlet is on the right side, and a slight distance. If I plug everything in, I can either rest the CTEK on the hood of the car (like the black trim where the windshield meets the frunk), or I can let the actual module hang on the floor. Is there a preferred option? Would it be bad to rest on the car?

Thanks!

 

Best to ask the previous owner which battery setting he used on the CTEK instead of second guessing.

You can have the module hang on the floor, no problems whatsoever.

BTW, the CTEK MXS 5.0 is the "latest" top of the line for normal batteries, it's a great unit especially compared against the Porsche branded CTEK which is ancient and lacks nearly all the features found on the MXS 5.0.

 

A weeks or 2 should be no problem without charging.

 

I have the same tender on my 991.1. Hard wired at battery w/plug connector. You have an AGM battery, use the AGM setting. Mine is hanging in mid air on my lift post...you can put it anywhere but note that the unit will typically get warm.

 

They make a little rubber sleeve/jacket that can provide some protection to your paint if you are sitting the charger on the car.

CTEK (56-915) Black Bumper https://a.co/d/dBkTDba

 

Why leave it sitting on your car, I dont see anything good coming from that

 

Two weeks is nothing unless you have some aftermarket accessory draining the battery. I use my charger only while it is in winter storage or if I am away for several weeks. Plus I think our 991s go into a sleep mode after a few days or a week.

And if it is still the original battery as mine is, it is an AGM. But using the AGM mode if you are in the deep south with high temperatures is a bad idea as any VRLA type battery should never be overcharged. Just use the 14.4V setting.

By the way, you can get an SAE to SAE extension if the charging cable is short. Available in different lengths. I use one.

 

1) Yes, AGM option.
2) The charger gets HOT. Whether or not it will damage your paint I don't know but I wouldn't take the chance. I have the same CTEK model. Like jimmiejam above, mine is actually suspended in the air outside and away from the car. The cord goes in through a slight gap I leave open at the top of the window.

 

This is where it has been confusing. My mechanic said that he recommends it, as 2 weeks is long enough to drain from the battery. For what it's worth, I've only gone a week, week and a half so far, but my typical drives are maybe 30 mins in length.
The only after market thing I have that could be an issue is my Blackvue dash cam. I do have it set for Low voltage cut off, 12.0/12.5V. But since I've gotten it, I've actually unplugged it when I park at home. Anyone have any experience with this? Is the CTEK useful for regular use, if the Blackvue is constantly on?

 

I just got a Blackvue DR900X-2CH installed. I've never had a dash cam before. I did change the settings for "Low voltage cut off" 12.0/12.5 and "Cut-off timer" at 5H. Based on this, is it reasonable to leave the camera plugged in all the time? I've been unplugging it when I park the car in my house, afraid that it might drain the battery completely. But sometimes, I forget to plug it back in before I drive, which defeats the whole reason for having the camera. Was curious if having the blackvue would change your opinion on a week or 2 no problem without charging?

Thanks!

 

A normal drain is anywhere from 25 mA to a max of about 45 mA (in a 993), so in a week, that is 4.2 Ah to 7.56 Ah in a battery that is 80 Ah in my 2015 991.

And someone can confirm this but after about a week, my remote does not work unless I pull the door handle to re-activate the car's system. So it seems some electrical systems do shut down.

You can leave the battery maintainer connected if you like, but there are some downsides to it such as if you have a weak battery, you'll be able to start the vehicle, but if you park it somewhere during the day, it might not be strong enough to restart it later.

 

It's too easy to put the charger on. If I'm away for a couple weeks I'll put it on and know all is good when I return. My experience has been batteries last longer if you put them on chargers when not in use.

 

Here's how I handle this with the extension cable from CTEK. I zip tied the power cord for the charger to the garage motor braces and I just leave it hanging there all the time. Makes it easy to remember to disconnect it when departing