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The CTEK Lithium XS charger has a function to obviate this situation; here is what the user manual says:
BATTERIES WITH "UNDER VOLTAGE PROTECTION" Some Lithium-ion batteries have an on-board UVP (under voltage protection) that disconnects the battery to avoid it becoming too deeply discharged. This prohibits the CTEK charger from detecting that there’s a battery connected. To bypass this, the battery charger needs to open the UVP. By pressing the RESET-button for 10 seconds, the charger opens the UVP. During this process, the charging STEP 7 is lit. Once the UVP has been opened and the battery is ready to be charged, the charger automatically starts the charging cycle.
Similarly, the Porsche Charge-O-Mat user manual says:
BATTERIES WITH "UNDER VOLTAGE PROTECTION"
Some Lithium-ion batteries have an on-board UVP (under voltage
protection) that disconnects a discharged battery. This prohibits the charger
from detecting the battery. To bypass this, the charger needs to deactivate
the UVP.
1. Disconnect the negative terminal of the battery
2. Connect the red and black clamp in accordance with the picture below
3. Connect the charger to the wall socket
4. Select Li-Ion charging program and press the MODE-button for 10
seconds until one of the indication lamps is lit (procedure may be
repeated).
That's great info, thanks you! I did see that in the manual before I understood what was going on, so it didn't register and my eyes blurred over a bit when it said to disconnect the battery with 43 miles on the car. My bad. Makes sense now. I think I subconsciously parked that in the 'need to call Porsche' category if if got to that point. Also, the Porsche charger doesn't actually come with the clamps needed to do that, so without the optional adapter, you can't really do that. I actually did have the clamps so I can't use that as an excuse, but I mention it in case helpful to someone scratching their head over it in the future. Given all the hassles I experienced trying to use the cigarette lighter, I'd say everyone should get the adapter anyway. Either way, sounds like there IS a way to wake up the battery with the Porsche charger if you have the clamps and are able to disconnect the battery, so I stand corrected! Thanks again.
Edit: thinking about this a bit more, that procedure is a bit ironic and/or chicken and eggy. When the battery goes into UVP mode, you can't open the frunk. If you can't open the frunk, you can't disconnect the negative terminal of the battery to follow that procedure... That may be the other reason I glazed over this procedure in hindsight, since I was locked out of the frunk? I wonder what happens if you try that on the red frunk terminal in the footwell without disconnecting the battery? I'll have to get out the charger manual and see if it talks about that...
I'm going to add some clarity on a few of the comments above.
In regards to the LITHIUM Battery going dead and some one saying connecting a charger is not working to AWAKEN it because the Charger does not SEE the battery because the battery is not showing any voltage. This is accurate. As a safety precaution modern chargers will not start charging unless they see a voltage minimum. This is especially true for Lithium Batteries/Chargers since if you charge an unprotected lithium battery that has gone well below 8v it can over heat the battery and cause a Thermal Runaway event in some circumstance. But the fact is the Porsche Lithium Battery a higher quality Lithium Automotive Battery will have the low voltage cut-off to prevent the battery from ever getting to the severely over-discharged state where it is dangerous to recharge. But some Lithium Batteries on the Market still do not have these built-in protections still, so always look for that.
Now, back to waking up the Battery after if goes into its sleep mode after being over discharged. As the persona above stated there is a low-voltage cut-off setting at which point the Battery goes into a sleep mode to protect itself from a deep over-discharge that will damage it. But oddly it seems that Porsche is not telling the Customer how to wake up the Battery.... because just putting it on a charger will not do this. The fact is that to re-set the BMS ( the Battery Management System) in most higher quality Lithium Ion product requires a certain HIGHER PULSE of voltage and current to AWAKEN the Battery. It will vary but it is usually in the vicinity of 14+ volts. This then triggers the battery to awaken the BMS at which point it can/will accept a charge. I don't know why this is not common knowledge or an instruction set that is not given to the Customer or printed on the battery. So what ends up happening on the Cars with a Lithium Battery from the Factory is the Customer attempts to put it on a charger and the charger sees no voltage so does not take any action.... so the Customer is confused.
So now there are companies making Lithium Chargers that send out a few PULSES of energy upon connection to a battery and the Charger can then WAKE UP the BMS on the Lithium Battery. For example both CTEK and Optimate make Chargers with a BMS RE-SET feature on them. But we tested both and they do NOT send out a large enough pulse of energy to re-awaken most Automotive BMSs. So I reached out to both these companies and complained and told them their PULSES are way to low to AWAKEN a more robust BMS like in a Car Battery. They wake up our Powersports Batteries... but not our Car Batteries. So CTEK didn't respond and OPTIMATE did.... and they worked with us to develop a PULSE that was adequate to awaken a Automotive Battery BMS so that was awesome. I have not tested it on the new Porsche Battery but I would like to do that for sure since we heard of this problem on the Porsches, McLarens, and Mercedes since they all use the A123 Automotive Starter Battery. Anyway I think that is the problem with the newest Porsche Battery, it needs that higher voltage/current pulse to awaken it... but the CTEK versions can't so that it too low of a PULSE.
The Optimate that works for that is the Optimate 275.
I'm going to add some clarity on a few of the comments above.
In regards to the LITHIUM Battery going dead and some one saying connecting a charger is not working to AWAKEN it because the Charger does not SEE the battery because the battery is not showing any voltage. This is accurate. As a safety precaution modern chargers will not start charging unless they see a voltage minimum. This is especially true for Lithium Batteries/Chargers since if you charge an unprotected lithium battery that has gone well below 8v it can over heat the battery and cause a Thermal Runaway event in some circumstance. But the fact is the Porsche Lithium Battery a higher quality Lithium Automotive Battery will have the low voltage cut-off to prevent the battery from ever getting to the severely over-discharged state where it is dangerous to recharge. But some Lithium Batteries on the Market still do not have these built-in protections still, so always look for that.
Now, back to waking up the Battery after if goes into its sleep mode after being over discharged. As the persona above stated there is a low-voltage cut-off setting at which point the Battery goes into a sleep mode to protect itself from a deep over-discharge that will damage it. But oddly it seems that Porsche is not telling the Customer how to wake up the Battery.... because just putting it on a charger will not do this. The fact is that to re-set the BMS ( the Battery Management System) in most higher quality Lithium Ion product requires a certain HIGHER PULSE of voltage and current to AWAKEN the Battery. It will vary but it is usually in the vicinity of 14+ volts. This then triggers the battery to awaken the BMS at which point it can/will accept a charge. I don't know why this is not common knowledge or an instruction set that is not given to the Customer or printed on the battery. So what ends up happening on the Cars with a Lithium Battery from the Factory is the Customer attempts to put it on a charger and the charger sees no voltage so does not take any action.... so the Customer is confused.
So now there are companies making Lithium Chargers that send out a few PULSES of energy upon connection to a battery and the Charger can then WAKE UP the BMS on the Lithium Battery. For example both CTEK and Optimate make Chargers with a BMS RE-SET feature on them. But we tested both and they do NOT send out a large enough pulse of energy to re-awaken most Automotive BMSs. So I reached out to both these companies and complained and told them their PULSES are way to low to AWAKEN a more robust BMS like in a Car Battery. They wake up our Powersports Batteries... but not our Car Batteries. So CTEK didn't respond and OPTIMATE did.... and they worked with us to develop a PULSE that was adequate to awaken a Automotive Battery BMS so that was awesome. I have not tested it on the new Porsche Battery but I would like to do that for sure since we heard of this problem on the Porsches, McLarens, and Mercedes since they all use the A123 Automotive Starter Battery. Anyway I think that is the problem with the newest Porsche Battery, it needs that higher voltage/current pulse to awaken it... but the CTEK versions can't so that it too low of a PULSE.
The Optimate that works for that is the Optimate 275.
I was hoping you might swing by. Any idea why the owner's manual and battery say not to put the negative charger clamp on the negative battery post? There is a separate post off to the side for ground. For lead acid batteries, I understand the spark can create a risk of blowing up the battery. Is that the true on a lithium battery too? Or is there something else going on with the lithium batteries that makes it a problem to charge at the battery posts?
p.s., as to the user manual procedure above about waking up the lithium with the CTEK and/or Porsche chargers -- is this the pulse you found to be too low? And why would you need to remove the negative battery cable?
I was hoping you might swing by. Any idea why the owner's manual and battery say not to put the negative charger clamp on the negative battery post? There is a separate post off to the side for ground. For lead acid batteries, I understand the spark can create a risk of blowing up the battery. Is that the true on a lithium battery too? Or is there something else going on with the lithium batteries that makes it a problem to charge at the battery posts?
p.s., as to the user manual procedure above about waking up the lithium with the CTEK and/or Porsche chargers -- is this the pulse you found to be too low? And why would you need to remove the negative battery cable?
There are a few different reasons that I am aware of but I think they all might have a little truth behind them. But I have heard this being more recent thing due to keeping the IBS (Intelligent Battery Sensor) and Electronics safer.
- The one you are saying about blowing up the battery would be rare.. but the reason for saying that statement is because some types of Batteries like a vented FLA (Flooded Lead Acid) Batteries will vent Hydrogen gases when being charged and Hydrogen is explosive... but this does not happen with AGM Batteries since they are sealed. Rare but possible on the venting of Hydrogen.
-The reason I have heard for this on Modern Cars mostly is to not damage or the electronics and the IBS that are now often hooked up to the Negative Cable on so many Cars. Meaning they fear some surge spark or something from the JUmper Box might damage the IBS, or Electronics since the post on the battery is what they are connected to. Whereas going to a Post that is a raw ground makes for a path that is not so directly interconnected to sensitive electronics.
- I have also heard it keeps the chances of mis-connection down also.
So I think all three have merit to some degree on their own, but together they all make sense and for a LIthium Battery it WILL NOT EVER release Hydrogen or any other Gas when charging. We have jump started our batteries via connecting to both terminals without damage, but when looking at the overall picture, I too agree we should just use the ground post rather than the negative terminal on Modern Cars so we stay away from the potential damage to the electronics or IBS during a jump start.
Also, I forgot to mention the original discussion was asking about voltage changes during driving... and those will change because the Alternators used on the modern Porsche are Smart Alternators, or variable voltage alternators that will charge higher during colder weather since lead requires more voltage during cold periods to charge as it does in a warmer temperature, and the voltage will vary if you have your car in Sport mode or Modes that use more energy, or if you have the air conditioning or seat heater "on"..... and this will also depend on the state of the charge of the battery itself since the cars IBS (Intelligent Battery Sensor) is continually monitoring all this via one of the onboard computer systems and then changing the voltage to the battery as different scenario occur. So the voltages can vary and it nothing to really worry about really if the car is operating correctly. But the thing to look out for is if you electronics start doing odd stuff this is usually and indication that the battery is going bad or is low and needs a full charge to get back up to a higher state of charge, or even needs replacing. Often times if you not driving much the battery can still read decent but its in a low state of charge and doesn't get fully charged by a 20 minute drives do you need a full charge on it. Other times it just going bad.
I was hoping you might swing by. Any idea why the owner's manual and battery say not to put the negative charger clamp on the negative battery post? There is a separate post off to the side for ground. For lead acid batteries, I understand the spark can create a risk of blowing up the battery. Is that the true on a lithium battery too? Or is there something else going on with the lithium batteries that makes it a problem to charge at the battery posts?
p.s., as to the user manual procedure above about waking up the lithium with the CTEK and/or Porsche chargers -- is this the pulse you found to be too low? And why would you need to remove the negative battery cable?
I saw that a in the above picture. You are NOT supposed to hook up the neg (black) to the battery. Separate post away from the battery.
Any idea why the owner's manual and battery say not to put the negative charger clamp on the negative battery post? There is a separate post off to the side for ground. For lead acid batteries, I understand the spark can create a risk of blowing up the battery. Is that the true on a lithium battery too? Or is there something else going on with the lithium batteries that makes it a problem to charge at the battery posts?
p.s., as to the user manual procedure above about waking up the lithium with the CTEK and/or Porsche chargers -- is this the pulse you found to be too low? And why would you need to remove the negative battery cable?
The owner manual says "connect to ground post and not to battery negative", because that is "safe" and was written in previous manuals.
MY OPC confirmed in writing that for the 992 LiFePO4 battery (60Ah), you can permanently connect a pigtail directly to the battery "+" and "-" or, alternatively, to the battery "+" and the chassis "-" (mass point).
Last edited by Joan Alcover; 04-26-2021 at 04:44 AM.
Have no idea how it actually discharged but none the less it happened overnight. She got going with the assistance of Porsche road-side after failing to get the frunk open with a typical car to car boost.
Couple of trick issues/suggestions:
-Keep your charge cables or booster out of your Frunk or be prepared to tear off fender liners on the passenger side looking for the manual release.
-Needed to boost the the fuse box to get the trunk to open. Make sure the fuse box red terminal is pulled all the way out and attach negative to door hinge
-Like above, NOCO booster will not detect voltages below 2v. He had to hit bypass button first (!) without grounding to get it detect the battery then do a boost cycle with negative attached....hood finally released.
-Battery fired up with boosting to positive terminal in frunk and grounded to frame.
-Everything settled in at 13.4v on the drive. Be sure to drive in Sport mode or in Individual with stop/start function turned OFF.
I bought a NOCO Boost Plus GB40 to keep under the passenger seat. Technician used a NOCO GB70.
Last edited by Pad Bender; 03-15-2021 at 01:35 AM.
I had problems as well. I was fiddling to long with the car on but not running and a warning light popped up saying "powering down due to low battery" or something. Jumped out of the car and went to bed.
Next day dead. Nothing.
Luckily the windows were down and in the garage.
Had to use the boost in the fuse box to open frunk
Jumped the car from jumper cables - positive terminal in frunk and grounded to frame.
Drove it for 30 minutes but a low battery notification was still there.
Trickle charged it 2 nights straight till CTek Lithium LiFePO4 charger said fully charged but the notification is still on. WTF.
Works great and drive it around town today for hours. In and out of the car. Starts fine but notification for low battery still on. PITA. Will have to go to the dealer to have them clear it I guess. Does anyone know how to clear the notification?
Bummer, sorry about that. That was my fear, but I have no codes/messages. I know on the earlier models, things like oil service lights and similar codes are removed with a fancy electronic tool, so most people just go to the dealer. I'd assume it's the same for our cars, but haven't really confirmed that. Google 'Durametric' to get the idea, but there are cheaper versions out there that claim to remove codes, etc.
p.s., Pad Bender's tips are all consistent with my experience, especially the part about pulling the red frunk charger tab all the way out. We pulled it out far enough to clip on the power, but unless it's pulled all the way out, there's no electrical connection and you might as well clip the power onto the tires
Have no idea how it actually discharged but none the less it happened overnight. She got going with the assistance of Porsche road-side after failing to get the frunk open with a typical car to car boost.
Couple of trick issues/suggestions:
-Keep your charge cables or booster out of your Frunk or be prepared to tear off fender liners on the passenger side looking for the manual release.
-Needed to boost the the fuse box to get the trunk to open. Make sure the fuse box red terminal is pulled all the way out and attach negative to door hinge
-Like above, NOCO booster will not detect voltages below 2v. He had to hit bypass button first (!) without grounding to get it detect the battery then do a boost cycle with negative attached....hood finally released.
-Battery fired up with boosting to positive terminal in frunk and grounded to frame.
-Everything settled in at 13.4v on the drive. Be sure to drive in Sport mode or in Individual with stop/start function turned OFF.
I bought a NOCO Boost Plus GB40 to keep under the passenger seat. Technician used a NOCO GB70.
I will report with Pat's post quoted to see if that sends him a notification...
I had problems as well. I was fiddling to long with the car on but not running and a warning light popped up saying "powering down due to low battery" or something. Jumped out of the car and went to bed.
Next day dead. Nothing. Luckily the windows were down and in the garage. Had to use the boost in the fuse box to open frunk Jumped the car from jumper cables - positive terminal in frunk and grounded to frame.
Drove it for 30 minutes but a low battery notification was still there.
Trickle charged it 2 nights straight till CTek Lithium LiFePO4 charger said fully charged but the notification is still on. WTF.
Works great and drive it around town today for hours. In and out of the car. Starts fine but notification for low battery still on. PITA. Will have to go to the dealer to have them clear it I guess. Does anyone know how to clear the notification?
03-10-2021, 09:42 AM
