TKEES

Hey Guys,

First post. Did some digging (on this site and teamspeed) and couldn't find an answer. I'd appreciate some direction from any owners if they have experience storing the Porsche Lithium Ion Battery. The car is about to go away for the winter season and last time I stored the car (on the Porsche trickle charger) it didn't do the job. Any help would be appreciated, my dealership has never seen this battery (outside of my car) and don't have an answer for me. Porsche Motorsport NA is also unable to help, I even tried calling the manufacturer to no avail. It's as though I am speaking about a phantom part. I'm sure these pieces were rare but, I'm sure you guys will know best.

Thanks,

Nizer

Open hood and both doors, disconnect negative lead on battery, close both doors, don't close hood. It will happily sit this way for as long as you want.

stout

Have you checked with CTEK?

I'm curious which factory setup you use (I have seen the CTEK charger rebranded as a Porsche charger, as well as Aston Martin, M-B, etc.), but there is a setting on CTEK's own version of the charger specifically intended for Optima dry-cell batteries. That's not your battery, but it is an indication that they "get" car people and their special batteries. Anyway, I met the CEO a few years ago. He's a total car nut and demonstrated how his charger will not allow a car battery to draw too much (also will not charge on reverse polarity, nor if water is introduced to the battery posts). I was impressed enough that I've bought several as gifts for friends over the years. I have no affiliation with CTEK and am not recommending their product for your application, but I'd be very curious to see what they would say. For those who don't want to disconnect their car battery—and many shops advise against it with the new cars—it might be a way to go. Or, at the very least, advise a charger maker of a need.

pete

Spleenache

Li-Ion batteries will not charge using standard chargers whether it is Ctek or another brand. Please do not try since you are likely to damage the battery. They require a completely different charger. I do not have the Porsche Li-Ion; i have the lithionics (http://www.lithionicsbattery.com/auto.html. You can get some answers to charging questions in the Lithionics web page too.

These chargers are more expensive then the regular chargers. I was advised to fully charge the battery before storing it.

Nizer

I have high-end CTEK charger. Never felt comfortable with it. Even in maintenance mode I could hear fluids bubbling inside the battery if I listened closely and I killed one (regular) battery using it. I would never consider using it on $2k+ Lion battery.

Process for resetting car after battery power is lost is laid out in the manual and very straightforward. Reconnect power, turn on the car and close the windows then hit the window button again after they're closed and they're set. Electronics reset themselves by the time you back out of the driveway and drive 20 feet. Never once had an issue. JUST DON'T CLOSE YOUR HOOD WITH POWER DISCONNECTED. It's a bear to get to the battery with hood latched and no power.

stout

Appears to be good advice above...and good to know.

stout

Both interesting and scary...never heard this before, but noted.

Have used the factory procedure for reestablishing power after replacing 9x6/9x7 steering wheels, seats and other fun stuff I wasn't going to touch unless the car was powered down, but...

...this is the thing I am not as comfortable with as I once was. While I never had a problem, either, Tony Callas and Tom Prine did an article on why it's preferred to use "jumper" power in the modern cars when switching batteries, etc. to keep continuous power.

I remain somewhat amazed that a fix for this snafu wasn't introduced more than a decade ago...

pete

Spyerx

I was under the impression that LI-Ion batteries for cars has circuitry that allowed the use of normal chargers. Why? Well they are installed in a car which was designed for lead-acid batteries... so the circuitry effectively allows the LI battery to act like a lead acid battery to whatever is connected to the terminals.

For example, look at this thread from voltphreaks who responds to a question on a ctek with their batteries:
https://rennlist.com/forums/997-gt2-...group-buy.html

ShakeNBake

For a $3000 battery I will use a Porsche approved charger to maintain the warranty....and I'm on the 2nd battery already. I think there is a 3rd party Lipo battery available for less cheese that is lighter, more stored energy, and totally transparent to the charging system (has it's own power electronics for converting charging current/voltage).

Spyerx

I get the warranty issue... Does porsche have a different charger they recommend for LI batteries? I thought it was the same one they "normally" sell for use with lead acid batteries.

ShakeNBake

I don't know...mine came with the car. It seems to be a standard trickle charger with the Porsche logo in it.

But...my point is, ask the dealer, get it in writing....then no worries. People asked why BMW had special oil for the S54, S85, and S65 engines...WTF just use what they recommend and don't over think it. They all go boom eventually.

cbweaver1

If you are comfortable changing a battery out yourself here is another option that can give you some peace of mind:

1.) Buy an after market perfect fit battery with warranty that has the nipple on the side for the vent tube--they are cheaper, have more power and last longer than OEM. Install this battery for your winter storage.

2.) Use the Porsche OEM charger (which is a private label CTEK) to maintain the heavy duty battery over the winter. I do this and have never had a problem. The OEM charger is good but it can stop charging or over charge. You will know as the green battery light will flash orange! When this happens, unplug the wall outlet first then the car end, then plug it back in reverse order. These intelligent trickle charger systems are excellent but not fool proof. If you can't glance at what the indicator is telling you a least once a week then find somebody to do it for you

3.) Save your $3k Li-Ion battery by keeping it in doors for the winter. Use this as back up if your winter battery dies. It is easy to pop the hood with a spare battery via the fuse box inside the driver's footwell. The manual goes has a straight forward explanation on this.

Ur20v

Bubbling of a lead acid battery under charge is all part of the chemistry: Formation of gas bubbles in a lead acid indicates that the battery is reaching full state-of-charge (hydrogen on negative plate and oxygen on positive plate).

I run a Voltphreaks VPR-S40 battery (Very pleased with this battery) and use CKEK no problem, this battery does have the balancing circuit built in which is important to protect the battery. You can't use a charger that goes sulfation mode.

If you are going to leave the hood pooped, put a piece of polystyrene by the latch so it can't be closed along with a note why not to close and why the block is there so it doesn't get closed by a 'helpful' passer-by. it can be opened if this does occur while the battery is disconnected but its a pain removing the wheel arch liner to get at the 'emergency' release cable.

Jay

Steve W

You cannot store the car with the lithium connected over the winter or you'll destroy it withn 2-3 weeks when it becomes completely discharged. Once a lithium cell is discharged completely, it is non-recoverable. The Porsche lithium battery is an 18Ah battery, consisting of four 3.6v 18Ah LiFePO4 cells in series, netting a 14.4v 18Ah battery. With the car in sleep mode, the car consumes just under 1Ah per day. Sleep mode is the mode of least power consumption and is achieved by locking the car. If you leave your doors unlocked, you can expect the power consumption to double or triple to 2-3Ah daily. There is an beeping alarm built in warning you when the voltage gets too low and requires you to get the battery charged up ASAP, either by running the car or with a proper charger. Even with a charger, the proper way to charge lithium batteries is with a smart charger that balance charges each of the internal four cells to they have equal capacity. RC and EV hobbyists know this fundamental all too well. But unfortunately the Porsche battery does not have a balance charge port so eventually the the cells get highly imbalanced, where you can have one cell storing 18.5Ah, and another only 5Ah, etc., netting the battery capacity as nothing higher than the capacity of the lowest cell. Battery packs such as in your laptop, cordless power tools, or your Prius or Tesla contain circuits that maintain proper charge balance of the cells so this doesn't happen, and unfortunately the Porsche battery also does not have such circuitry.

There is also the danger of overcharging a lithium cell which can cause an explosion or fire. With a lead acid battery, the excess current/voltage ends up boiling the electrolyte. In a lithium cell, the electrolyte is part of the paste that contains the lithium which overheats and puffs up the cells, causing the type of explosions and fires you hear about with the Fiskser Karmas, Chevy Volts, the Boeing Dreamliners, exploding laptops and iPhones, etc. You may have also heard about the GT3s that had their lithium batteries just unexpectedly explode into a fire while it was in a dealer service department, probably because it was connected to a high current standard battery charger.

I would remove the lithium battery, and install your standard battery and connect a standard battery maintainer to the car to keep the battery topped instead. A CTEK or Battery Minder is good as they have a desulphating mode for lead acid batteries. But do not use such maintainers with lithiums or the desulphating mode destroys lithium cells. If you really don't want to swap the batteries, then just disconnect the cable from the battery and leave the trunk lid open and unlocked.

If you prefer not to disconnect or remove the battery, the alternative is to use a battery maintainer connected to the car to provide the maintenance current the car is drawing constantly. Some lithium battery makers claim a the tender made by the brand Battery Tender can do the job as they are just simple maintainers without the desulpahtion mode. CTEK recently came out with a lithium charger/maintainer claiming to be able to maintain the cells of a vehicle with a lithium battery, but neither of them utilize the traditional balance charge ports to keep the cells in balance, I would be skeptical of their operation for the reasons outlined above.

Ur20v

^^^This, but not all Li batteries are as poor as the OEM offering.