Steve Cole

I drove my car yesterday despite the amount of sand still on the road (but the salt has been washed away with days of rain), and after sitting for 10 weeks with a few battery checks by unlocking the doors and seeing how bright the headlights came on, the car fired instantly, exhibited zero problems. So, I think the fabled battery draw, at least with a 991.2 TTS, is over-stated. The key might be, according to some I've seen talking about this, that you keep the doors locked. Their feeling is that this allows the computer to put the car into "deep sleep" after some number of hours of being unmolested.

SamboTT@ByDesign

Yes it goes to sleep for the most part. Porsche still even knows when you dis-connect the battery or lose power.

Randyc151

OK, I took my car over to the dealer today, because they said they needed to initialize the new battery to the car. What they did was just program in to the car that the Porsche Techquipment lithium battery was installed instead of the OEM battery. I have no idea if that makes any difference, nor did the senior tech. They charged me for 1/2 hour of labor, but it took more time to find the Porsche lithium battery part number than the programming lasted. I was in and out in 15 minutes. All in all, the car performs identically in every normal situation so far, and I am feeling good about this swap to lithium.

SamboTT@ByDesign

Sweet Randy

Antigravity

Hey Steve, this is actually VERY GOOD news, because this means they are making the effort for the "sleep mode" in the Car to really lower the current draw after it realizes the doors are locked and the vehicle is just going to be sitting. For those using smaller Capacity Lithium Batteries in their vehicles that means they will have longer storage times even with a battery with lower Amp Hours than their stock Lead/Acid batteries. Additionally this means if you do have it on a charger you will not be getting as much "cycling" of the battery from the charger during storage. I assume this is something quite intentional from Porsche. McLarens also have a great sleep mode and they intentionally focused on that over the last 3 year since the early models sucked the battery dry very fast.

Keep in mind that the high Parasitic draw is not a fable... it's real and you will hear me bring it up because that is exactly what will ruin batteries be it Lead/Acid or Lithium the fastest. I'm just telling everybody to watch for it.... an over-discharged battery is the #1 cause of short battery life or eventual failure.. And a lot of cars have large Parasitic draws.... though the newer Porsche may not. If you keep any battery in it's top 15% state of charge you are keeping that battery in a position for it longest life and not giving it opportunity to be damaged. One accidental deep over-discharge will significantly damage your battery cells and decrease the life span. And lithium is much more sensitive to that than lead, so the lithium will show the effect sooner since it is not a massive chunk of lead.

But keep in mind that there can be many other things that create these Parasitic draws. For example the theft deterrent system and immobilizers some stock and some aftermarket that cause very fast parasitic drain on batteries, because they are constantly monitoring the cars... Nowadays and it seems in the latest cars they have worked some of these out to go into sleep modes drawing less current, but that is not the case in many cars still. Additionally, keep in mind that many cars have proximity detection in their keyfobs... so if you are close to the car it actually wakes up basic systems and the car is linking with the keyfob and creating a higher level of draw as it awakens the systems.. so even if you car is in the garage but not driving it each time you are walking by it or hanging out next to it it drains the car. A Mclaren guy was sayin he never knew why his battery drained every few days and he was storing the key in a drawer in the Garage Cabinets... there for keeping the system alive. Last putting some aftermarket stereo in or accessory, or Power Commander type of things will often be installed and not a factory part and they can also create fast draws on the system. The bottom line being, over-discharge from the Parasitic Drain is the most likely accidental reason a person will come back to a dead battery... so watch for it. But I'm glad to hear you .2 is barely drawing energy.... it more reason for people to look into lithium!

Randyc151

What does Antigravity offer as to chargers for automobile lithium batteries? What are your thoughts on this Porsche model: https://www.suncoastparts.com/product/CHARGER2.html

Should any charger for lithium batteries work, or do you need to go with the specific one for each mfg.

Antigravity

Good info...now others know what's entailed.... wish theTechs could tell you what the change actually does...that would be good information for us to know. I will try calling around also to find out.

You will do great with lithium... you did all the correct things by getting the correct charger and understanding it, and I've read your posts and you seem like an intelligent person who maintains their car so you are going to be fine.

And if you didn't know, extra pounds of weight are exponentially heavier at speed. For example you have Concrete block that weighs 10 pound and is traveling at 30MPH the force required to slow that down is say "X" but if that block is going at 60MPH and you try to slow it down, it is no longer just 2X the force required to slow down the block since you only doubled the speed... its actually something like 3.5X the force (or some other specific number I don't remember from class) required to slow that down because the the force required to slow down that mass goes up exponentially as speed increase.... So when you are talking weight savings of 10, 20, 30 or 40 pounds it is MASSIVE when you are slowing things down from 100 MPH or more since that mass become exponentially harder to slow down. So while 10 to 20 pounds sound pretty good as a regular number and the car sitting static... When you put it to high speed it becomes really significant reduction of mass to be slowed down from higher speeds.

Antigravity

Hey Randy, this is something I'm glad you brought up... Chargers. As a disclaimer I have NOT test EVERY Lithium Charger on the Market... but we have test all the Major brands.

Here is the issue with Chargers. There is a special algorithm that a charger should follow for a specific battery chemistry to be charged correctly... and this charging algorithm can change as the battery is being recharged. For example for a battery starting at a super low voltage (over-discharged state) the Charger would want to follow a certain algorithm to massage it back up gently until a certain voltage at which point it can then start charging it faster with higher voltage. So the charger will step up the charging profile as the battery's state of charge goes up.. a good charger will also step back and test the battery again during its charge cycle to make sure its taking the charge correctly. So this is what most "Smart Chargers" do nowadays.... But where this gets tricky is that many manufacturers who deal with Lead/Acid Batteries come out with a "Lithium" Version of their Charger where they mildly tweak this Lead/Acid charging algorithm, but it is not really proper for lithium. So it can end up not massaging an over-discharged Lithium Battery as well as it should, or excessively cycles the lithium.

There are two brands that do it correctly.., Optimate/Tecmate and CTEK. We got our share of warranty returns from over-discharged batteries before we had all the new protections.... And the only chargers we used to bring back those over-discharged Warranty Claims are those brands and we have tried all the major brands. They both do SPECIFIC Lithium algorithms and know how to correctly charge lithium, and in many cases these brands have brought back some lithium batteries that were at 4v and saved them. Keep in mind since the battery was taken to 4v it is still suffering some damage.. but these chargers actually saved them, while many chargers can't bring back over-discharged Lithium Batteries, or they puff them out when trying to save them because the algorithm is not correct. Again we have not tested them all, but we have extensively tested, and actively use them both those brand DAILY, and both they have never damaged our batteries and are great... I will say do not ever get Battery Tender stuff... even Optima Batteries and Odyssey Batteries say in their warranties they will void if you use Battery Tender Charger.... that's sort of funny.

As far as these two Brands... CTEK makes all the OEM chargers for most all the European brands and some American companies GM, McLaren, Porsche, Audi etc.... they make both Lithium and Lead Acid chargers..... It is the same for Optimate.. but Optimate does more the Motorcycle Industry Like Honda, Yamaha, Ducati... and is big in Dealership's garages . So both are well tied companies who do it right. The Optimate had more saving/testing features during its start up than the CTEK... but both are great.

So the Model you show that is labeled a Porsche Charger is actually a CTEK OEM'd by Porsche.... It is a 5A model which is good for faster charging if ever needed. So that is a good choice. But, if you don't want to pay for the Branding of "Porsche" at $209 dollars, that same model labeled as CTEK own branding is about half the price and will be exactly the same. The equivalent 5 amp Optimate is about $120 dollars.

Randyc151

So this one: https://smartercharger.com/products/...ek-lithium-us/

Or this one: http://optimate1.com/product/optimate-lithium-4s-5a/

The Braille charger says to never leave it unattended, so I'm not sure it's designed to do maintenance mode

Antigravity

Yes those are the best chargers.... you will notice that the Optimate is a little more expensive... but it does have some cooler features for what it's worth. It goes through a complete test procedure before it starts charging and will warn you if there is any anomaly. So they both work fine but the Optimate is a bit more into the test and recovery for lithium which is valuable from my perspective for the couple dollars more. It physically a little larger, but also claims rain proof... and they are built sturdy for sure.

As for the Braille charger saying never leave unattended..... All chargers will have that in their Users Manual its part of the safety instructions for any charger or re-chargeable products. My Electric Bike with a Bosch Charger and Battery (top quality stuff) also says that, and even more scary stuff like loss of life could result if used wrong... but it a legality. Theoretically you are never supposed to leave ANY thing charging unattended. I actually make all the guys unplug any batteries that are charging when we close. On the other hand I have left many charging overnight at my house and still do... But yes it counterintuitive for a Maintainer to say never leave unattended when it is meant to stay on the vehicle. It just due to that fact that anything could happen and you want to be legally safe with the disclaimer.

Randyc151

Actually, both Optimate and Ctek state that they can be left to maintain the battery without worry!! I think I will grab the Optimate and just see how all of this goes. Your advice has been a big help. I can't wait to see what you guys finally roll out to this customer base!

SamboTT@ByDesign

Optimate is a great one! My 5 year old can operate it haha. So simple and works great. It's really for just in case in the case of the Braille. I have never had an issue after 10-12 and a few years in all weather and sitting for long periods too. Including a 4 month engine build deal where the car sat. Great to see other options as well.

carguy84

I wonder if Porsche needs to update the ECU so that the alternator doesn't pump out as much voltage? I often see 15.2 volts coming from the alternator and I'm not sure if these Lithium batteries have the electronics built in to drop that voltage down to < 15V?

Randyc151

I believe so. So far, sitting for a few days between drives, the car still fires up with immediacy. Continue to feel great about this swap.

stealthpilot

This is a very cool product, but it feels a bit like cutting weight at the wrong section of the car.