Fullyield

You make good and valid points. But, I replace my AGM battery every 4 years for less than $200 which is about $500 total cost over 10 years. Plus the AGM battery is available anywhere and everywhere. I can use any brand. So, it’s $1850 every 10 years for a proprietary “Porsche” LI battery (if I can find one) or $500 every 10 years for AGM batteries I can get anywhere. I love the idea of RAS. Sole reason I did not order it as an option was the LI battery issues. I sympathize with our Canadian members who are not given a choice in the matter.

CodyBigdog

Price wise, I assumed what my Porsche dealership charges. All bets are off on price comparisons if you use something else and DIY. But appreciate the AGM batteries are cheaper and found everywhere.

As I mentioned, I suspect Porsche is expecting most of it’s customers to trade-in their 911 before the clock strikes midnight at 10 years. 10 years is a very long time when it comes to automotive innovative changes.

I think the real “gotcha” is that this battery is “proprietary”, not so much the price (since $$ isn’t a real issue for most Porsche owners).

As an aside - knowing what I know about the LiPo battery, etc….I would still opt for the option if it meant that’s what I had to do to get RAS.

Antigravity

Hey Null,

You question is on the shelf life of the LIFEPO4 Battery.... here some points to consider.
- The BMS (Battery Management System) is what can draw down the LIFEPO4 Battery more quickly that it would otherwise. For example the BMS puts a mild self-discharge on the lithium battery pack in the case of our Antigravity Automotive Battery line, and it could possibly be a much higher self-discharge in the Porsche Battery being it probably has a more active BMS than our since it also arguably more electronics inside to send the data points (voltage, current, temp) to the Porshes system. So that could be a main reason these Porsche Batteries are discharging faster than a typical Lifepo4 Auto Battery like ours.

But I do want to point out we make Racing Batteries without a BMS and those products are amazing because they can sit on a shelf about a year and still have 13.2v in them. But they do not have the Protections of a BMS system so that is a double edge sword and not recommended for Street Cars. The point here being Lifepo4 can actually hold a charge up to a year when not connected to anything that draws energy, but once you have a BMS it will reduce the shelf life by a good amount, and that will ultimately depend on who is making the BMS. So I can't give you a hard number but can say for our Antigravity Batteries if you have it on a shelf doing nothing after a full charge you can get about 6 month of sitting without being connected to anything before we would say put a charger on it again. But for the Porsche Battery it may only be two months ( I dont' know at all) since it might have more active electronics on their BMS to be able to do what it does. Sorry I can't answer better on that.

CodyBigdog

Have you guys - recently, or in the past - reached out/ approached Porsche to see if you could be a secondary, if not primary, supplier to them for the LiPo batteries? Seems they need help in this area?

IXIXI

How safe is it to leave either the Porsche or AGravity battery on the proper charger/trickier for the duration of winter months?

siberian

No problem with that.

As to the points raised concerning alternative batteries. With all due respect, the entire point is moot. We can't have a LiFePO4 battery sans BMS period. Nor can we modify via PIWIS (or certainly way beyond anything I would be willing to do) such an equipped car to accept an AGM battery and at that point also be able to disconnect RAS since AGM doesn't have the amperage needed for the current surge required by RAS.

Lastly how long a battery can theoretically sit with or without Porsche BMS is again moot unless you can actually test out the viability of the BMS software and harness prior to buying a "spare" one for when you need it, until Porsche gets off it's proprietary wagon. This is not like buying a spare quart of oil.

It's unfortunate but until any vendor comes up with a cloned LiFePO4 with a Porsche BMS (let's look at China) substituting or buying a spare is IMHO moot.

siberian

Antigravity

From the data that some have stated.... it would actually appear to be the battery. I am saying that from what I have read in terms of the Dead Battery scenario, not just a battery saying its low as a flag... It appears the batteries can't be woken from their Protection Modes, or the Dealers are saying there is a damaged sensor in the Battery. This would not be caused by the Cars BMS , but rather the interior BMS in the Battery itself. Anyway, its a truely ridiculous issue and shows that over-engineering rarely works and creates a greater problem the the supposed issue it resolves. This was no more than Porsche's attempt to create a closed system that Porsche could control the pricing on, and not allow the Customer to be able to replace one of the simplest parts of a vehicle. My Porsche should make Proprietary Tires for their vehicles next!

Also $2k for a Battery is getting pretty darn crazy and especially if they are not getting about 8 to 10 years. I would be scared to buy a Car if I came in armed with the knowledge that I'm buying something that will cost me an extra 2k every few years for such a simple product as a battery.

siberian

Could very well be. Or it could be the BMS code or a faulty harness (less likely but...)

You're very right it's ridiculous this proprietary business (have faced that along my IT career many times) and along the vein of the Porsche and the Mobil1 0w-40 ESP x3 oil for 992s that can only be gotten at dealers (though Mobil1 seems to be opening up a bit). I keep mentioning this, but customer loyalty is a fickle business and when you loose it it's gone.

siberian

Antigravity

No, we have not reached out to Porsche. The large Auto manufacturers are on different level, we talked to some that approached us, but I don't need it or like it really. Its a long proccess, it has many pitfalls and is best left to companies that are also very large, and do that scale of business.

But, what I can say is that we are in the new Paganis that are coming out toward the end of this year. Pagani reached out to us two years ago, so the new Car will have our battery, and they have also developed a retro-fit kit using our Antigravity Batteries for the previous and current models. So that is super cool for us.

Being blunt I know Pagani must have reached out to A123 Systems and several others who are way bigger than us... so I'm stoked they chose us. I think they saw we are small, and can develope stuff super fast, and we make stuff that does what we say. So they kept it simple which was smart, they could have put a more complex battery by A123 Systems but probably saw it was more engineering and tied them to only one product, and last larger companies like A123 are not fast... its all a slow process. For example we had to make a remote button for Pagani rather than our Wireless Jump Starting... we did that for them in a month and sent samples... a larger company would take 6 months to do that. We also are talking to and popular English Car maker of smaller sports cars but that has been going on two years also... so its a long process. So at this point we have a niche that is growing rapidly in several catagories, and that suits us just fine. I'm also a control freak and don't want anyone telling us what to do.

Antigravity

Absolutely and perfectly safe... no issues at all. These modern charger are designed to be left on cars without issues, and the batteries can handle it fine.

achilleas101

is it possible that the charger can damage the harness/bms/sensor on the battery?

i only ask because my issue w/ the sensor flashing low voltage started after i came back from vacation, when i had the car locked and on the trickle charger. it was fully charged, but when i started it, bam, warning light. So it freaked me out that maybe the charger fried it somehow. I use the CTEK lithium charger fwiw, not the Porshce branded, and used the battery positive, but a negative post terminal near the battery (couldn't reach the big negative post by the driver side), using that 'hardwire' ring harness, not the alligator clamps.

siberian

Possible but IMHO unlikely. Sometimes a cigar is just a cigar.

siberian

achilleas101

ha, yeah, i just LOOOOVE those coincidental errors. My favorite- had a 2003 A4, it was like 4 years old and i was checking the front left wheel out for play. Had it raised on a jack. Put it down, get everything ready to go, i turn on the car, and i get a check engine light. I'm like, WTF JUST HAPPENED? all i did was try to move the wheel back and forth. Did i knock something around?!? Turned out that a coilpack died. Just the random timing of it freaked me out.

siberian

I feel you. In these uncertain situations we tend to look for any and all possible or probable causes but at the end as a renowned sleuth once remarked "when you eliminate everything else then whatever remains however unlikely must be the cause". I think in this case it's unlikely to be a charger (whether Porsche, CTEK or other) but battery related. Now as to whether it's the BMS, physical battery or harness that's for a CSI autopsy to determine. Way beyond anything any of us (and I would venture most dealers) to determine. Most likely the latter will be told by Porsche to ship it home to them - and I doubt anyone will ever really know the cause.

siberian

Michigan 992

FWIW My 2S is now running RWS with a Porsche supplied AGM battery. Everything seems to work fine in 80 degree weather. I have no idea if that would be the case below freezing. I don’t know how big of an AGM they installed to make it work or how long the battery will handle this type of usage. Just has to make it to the end of July for me.