W5PWR

Recently my 992 GT3 Touring has been reporting an error Battery Low Inspection necessary.

The car is always left on a CTek CS-One, checking the voltage on the display is showing 13.4 and goes up to 14.2 during warmup so looks normal, does anybody know what is causing the error?

neanicu

Perhaps your car has sat a lot before you've taken possession of it and one of the battery cells is dead. You can check the battery voltage unloaded all day and it might look ok but in reality it might not be ok.
I would disconnect both positive and negative terminals and load test the battery : either by using a traditional load tester that puts a load on the battery for a few seconds or using a modern electronic battery tester that measures the internal resistance of the battery. For the latter you would need to know the Cold Cranking Amps that your battery is rated for so you can introduce the number in the tester.
If the battery checks out ok I would check for parasitic current draw on the battery : meaning something on the car is drawing the battery excessively instead of being asleep.

NeoLeo

So I had the same “low battery” warning on my 992.1 GT3Touring (2023). I took in for Service #1 at the local dealership. They ran diagnostics and determined that while the battery level was fine, there was a bad sensor on the battery itself. The Porsche dealer replaced the battery under warranty. I inquired the cost if it was out-of-pocket, and they cited about $1700 for the battery plus $800 for labor.

sparkhill

Mine was replaced under warranty for the same error a month or two ago. The battery tested good, so they made the leap it was a battery sensor error.

Seems like a common issue, and there was even a TSB on the Cayenne (WMJ9 – Re-Programming Gateway Control Unit (Battery Sensor) (Workshop Campaign).

if your CTEK is hardwired, you might consider removing, since I hear that might “void” the battery warranty.

993RR

Using the 12v socket is acceptable? What's the difference for the battery?

sparkhill

The 12v outlet is fine. I only mentioned the hardwire issue because I read somewhere that somebody's warranty replacement was allegedly denied by their dealer only because they had hardwired their charger to their battery. It should not matter, but why give any reason for possible warranty replacement denial of a known recurrent battery issue?