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HOWTO: Permanently Connect Battery Maintainer Terminals

Written by Wild Weasel

This is meant for 991 911 owners who want to make it easy to hook up a battery maintainer when they won't be driving their car for a few weeks or months at a time.

Skip to the Details.

Plenty of people ask about which 12 volt outlet they should plug their battery maintainers into. Some of them will stay live only if they detect a maintainer plugged in while others will turn off a few minutes after the car is turned off no matter what.

Even the ones that stay live can go dormant if you have a power outage and it no longer detects the current for a while. When the power comes back on they may not go active again and you could be left with a dead battery you weren't expecting. With the electronic frunk release on these cars, this can leave you with a real hassle trying to get things back up and running again.

So here's my solution. CTEK makes a connector to permanently attach to your battery terminals with a quick-disconnect plug on it that attaches to their chargers.

You may be questioning the installation as everyone knows you're not supposed to connect your charger directly to the negative battery terminal. Trust in me. I've done the research and the reasoning behind this is a cautionary tale from many years back when batteries could produce explosive gases and connecting to the terminal directly on the battery could cause an explosion. That led to laws and regulations that still make it a legal issue today for companies to instruct people to connect directly to the negative terminal.

I assure you this is perfectly safe and works exactly as you want it to.

Here are the Details

Firstly, it goes without saying that you should not try to drive the car with your battery maintainer connected. A few people mentioned this as a mistake they've made and suggested putting a piece of paper under the windshield wiper or on the dash saying "Battery Maintainer Connected" so you don't accidentally forget about it and drag it along beside your car.

The two key details I want to show here are where to connect the terminals, and how to hide the cable and connector when you're not using it.

As you can see in the pictures, the red and black terminals are attached directly to the battery terminals. It's as simple as that.

Battery Connection

Then, in order to not have the cable dangling around in there when it's not being used, notice that you can tuck it perfectly into the little box that holds the tire inflator. There's a gap under the lid at the back so you can run the wire without pinching it and space beside the inflator to tuck it in safely.

Cable Storage Location

When you want to use it just take out the connector, run it under the gap by the windshield, and plug in your charger.

Ready to Connect

CTEK Charger

One last thing worth mentioning is that I used to put a towel over the fender of my Boxster out of paranoia about potential marks on the paint. In this case, there's a PPF wrap on the car so I'm not concerned about the wire lying across it.

That's all there is to it!


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