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AGM refers to "Absorbant Glass Mat" which is a technology that helps reduce battery size and improve their reliability. They are capable to deliver high currents on demand and they offer a relatively long service life. AGM is maintenance free, provides good electrical reliability and is lighter than the flooded lead acid type.
That's the type of batteries our cars are using and your charger needs to specify that it can charge them.
Yes, if it moves to 4 lights fairly quickly, it's probably fine. An AGM battery will not have on it a vent tube, whose purpose is to vent hydrogen gas developed during charging. As noted above, AGM batteries are standard on 991s, so it's unlikely you have a standard battery (and if you do, you'd better find a way to vent it).
Once you've identified the battery as an AGM type, use AGM mode on a CTEK. My CTEK 7002 "remembers" the last mode, so if you unplug it or have a household power failure and it resumes, it will revert to the same mode you left it in. I don't know if other models do that. The 7002 also has a recondition mode, and a "supply" mode (so you can maintain power to the car during a battery swap, for example).
If you have a lithium ion battery (rare option on most cars, even Porsches; but you can get an aftermarket one, like Antigravity), you will need a charger specific to those because they require a different charge profile.
BTW, I know a few have reported bad experiences with CTEK, but I have five of them, some going back 7-8 years, and all have worked flawlessly. I have had other charger brands that have failed.
Yes, if it moves to 4 lights fairly quickly, it's probably fine. An AGM battery will not have on it a vent tube, whose purpose is to vent hydrogen gas developed during charging. As noted above, AGM batteries are standard on 991s, so it's unlikely you have a standard battery (and if you do, you'd better find a way to vent it).
Once you've identified the battery as an AGM type, use AGM mode on a CTEK. My CTEK 7002 "remembers" the last mode, so if you unplug it or have a household power failure and it resumes, it will revert to the same mode you left it in. I don't know if other models do that. The 7002 also has a recondition mode, and a "supply" mode (so you can maintain power to the car during a battery swap, for example).
If you have a lithium ion battery (rare option on most cars, even Porsches; but you can get an aftermarket one, like Antigravity), you will need a charger specific to those because they require a different charge profile.
BTW, I know a few have reported bad experiences with CTEK, but I have five of them, some going back 7-8 years, and all have worked flawlessly. I have had other charger brands that have failed.
I have found where is the best spot to attach a trickle charger to 991 Porsche. I have read where people plug it into footwell port in passenger side or plug in console box.
my question is does it work in those places ? I have tried in both spots and it appears that charger shuts off in a few minutes after closing door. I have read that both plugins go dead after a few minutes after closing doors .
who knows if it works correctly plugged in vs direct wires to battery
I have found where is the best spot to attach a trickle charger to 991 Porsche. I have read where people plug it into footwell port in passenger side or plug in console box.
my question is does it work in those places ? I have tried in both spots and it appears that charger shuts off in a few minutes after closing door. I have read that both plugins go dead after a few minutes after closing doors .
who knows if it works correctly plugged in vs direct wires to battery
The footwell port works fine, mine does not turn off even after locking the car.
i just leave the passenger window slightly open for the wire.
When you say it doesn’t turn off after shutting the door? What did you use to check if power is still on in footwell after car is closed up?
mine is fine when I hook it up and **** the door then after a while it shuts down until I open door again
When you say it doesn’t turn off after shutting the door? What did you use to check if power is still on in footwell after car is closed up?
mine is fine when I hook it up and **** the door then after a while it shuts down until I open door again
Check the lights on your battery tender that will show you it’s charging.
That is how I noticed it , when I first plug it up it’s charging come back to it hours later and charger is off not charging. That is why I say the ports seem to go dead after shutting down car so as to run your battery down case you left an electronic hooked up .
That is how I noticed it , when I first plug it up it’s charging come back to it hours later and charger is off not charging. That is why I say the ports seem to go dead after shutting down car so as to run your battery down case you left an electronic hooked up .
That doesn’t happen on mine, and I think a lot of people use this foot well socket for charging.
I've charged my car ('17 base C2) multiple times over multiple days with a CTEK Multi US as well as GOCO charger, via both the passenger side footwell socket and the central console socket.
I currently am using a GOCO 1A Genius unit, and have now directly connected the charger pigtail leads to the battery terminals with M6 nuts. I then have the pigtail routed out to just above the polymer frunk liner out near the passenger side windscreen wiper. When I want to charge, I connect my long 10' extension to the COCO 12V pigtail, plug in the GOCO to power (which resumes at the AGM setting, which I like) and lock the car. That's it.
Lately I've been placing a simple LED 12V outlet voltage monitor into the central console socket to monitor the charging voltage. At least "for me", the 12V LED monitor stays energized throughout so I can see the charging voltage on the battery easily from outside the car.
Last edited by Rich_Jenkins; 06-09-2020 at 09:55 AM.
I also plan to hard wire my Noco Genius G3500, it will permanently replace my Charge O Mat Pro. The G3500 is a nice unit and features 9 Charge Profiles https://no.co/support/understand-charging-steps
06-02-2020, 10:13 AM
