koven

i ended up ordering the H7, i like the remote tech and the weight drop is nice. plus i think my oem startup crank is feeling weaker these days so ill just consider the h7 a preventative replacement. as for price sure its expensive for a battery but whats a few hundred $ difference on a $100k+ car

MC129

Due for a battery and thinking about one of these for my track car. Is it necessary to reset through a PIWIS to Lithium? Also wondering if you need a seperate battery to maintain current to the system while swapping them out?

curta

With the management system and the Wireless Remote Jump-Starting do you still need to use a trickle charger when, storing the car for over the winter?

Antigravity

No need to change the PIWIS to function perfectly fine.... but YES there can be a benefit to changing it in a TRACK or RACE CAR.....

With the PIWIS change to LITHIUM in the PIWIS the MAX Charger Rate to the battery will be lowered 13.5v.... so when you are talking the sustained HIGH RPMS use of Track Driving this is beneficials..... NOT because our battery will be affected, but rather because it creates less DRAG from the Alternator on the MOTOR since the Alternator is not trying to output 14.5 voltage like it does when normally driving. So yes there could be a benefit in that circumstance.

Let me know if you understand what I'm saying.

Antigravity

This depends on the size of battery you get and if you have any extra accessories you added to the 991.

For example we have 3 different Amp Hours available in the H6 size Battery... 24Ah, 30Ah or 40Ah.... a 40Ah has a much larger Lithium Battery inside compared to the 24Ah.... so it has more Capacity (amp Hours).... so it can sit very long in the car and still start it after a 2 months in storage.

But if you have extra accessories like aftermarket Camera, Radar Detectors or things YOU added to the car then the Parasitic drain can be much higher than the normal a 991 has. As an example in our GT3 the 30Ah can sit over 7 weeks and still easily start the car...... a 40Ah is about 8 weeks sitting without needing a charge. But again this is with a stock GT3 no aftermarket things on the car. A Turbo would have a slightly higher Parasitic Drain, but should still get maybe a few days or week less due to it having more electronics on board than a GT3. But all the 991 in stock form have a very low Parasitic drain.

So it also depends how long you are storing it over the winter.... for example if you had a 40Ah... you could let it sit about 8 weeks... then maybe it would go into sleep mode... but if it goes into sleep mode you still have about a month to press the Re-Start and it will still start the car fine.... longer than that and the restart reserve energy is being used up... so you would actually have to charge the battery if you left it too long after it went to sleep.

So figure about every two months you should put it on a charger if you are storing it and go with a 40Ah battery. Less time with less Amp Hour models....

Let me know if that answers your question...

MC129

I understand.....thanks for the info!

rockrdude

Will the porsche battery tender that was given to me with my car ok to trickle charge your batteries?

PTS-BRG

You cannot use the Porsche battery tender to charge a Lithium battery. You will need a charger specifically designed to charge Lithium.

I think the majority of guys buying these Lithium batteries are doing so because they have lead batteries that are old or starting to fail.
In that case, I think the Lithium is a better value. For guys like me with a 2018 or 2019 car and a battery that is like new, its tough to justify replacing a perfectly good battery.

But, I still want one

Antigravity

Hey Rock... PTS answered this correctly... you don't want to use a Lead Acid Battery Charger.

The specific reason is because a lead acid battery charger often has a De-Sulphate Mode.... This De-Sulphate mode spikes voltage to a lead acid battery because the lead acid plates can develop Sulfate on them. A lithium battery is a vastly different chemical makeup and will never Sulfate. And additionally these spiking voltages can damage a lithium battery. The secondary issue is that lead acid chargers will usually cycle the battery more often because lead acid batteries have a significantly faster "self discharge" rate compared to lithium. So what ends up happening is the lead acid charger keeps trying to recharge the lithium battery much more often than is needed and this is called "cycling". So the cycling creates an unnecessary little charge on the lithium battery very often and lithium does not need that. And last a lithium specific battery charger will do a slower recharge rate if it senses the battery is at an over discharged level. This circumstance won't occur with our RE-START batteries because they have a protection circuit that will not allow the battery to over-discharge, but there are still a high number of UN-PROTECTED Lithium Batteries out there... including we still make un-protected RACE batteries.... so it is very imperative to use a lithium specific charger on these types of batteries so you do not overheat or overcharge them.

rockrdude

Thanks for the great explanation!

96redLT4

Hi Scott. I was surprised to find I had a Lithium Ion battery as the OEM in my 2015 BMW M4 daily driver. The car and battery are 5 yrs old now, and I am wondering how much longer the battery will last. Do you think it will go '8-10 yrs' as you quoted in one of the earlier posts? No one at BMW seems to know very much about the Li technology although they are happy to charge me $2K to install a replacement. The info I could find on the spec sheets touts a higher life cycle from this 69Ah battery but no idea when to replace. Should I buy your Li charger or emergency unit than replace it with an H6 40 when it finally dies? I guess the OEM BMW battery will last significantly longer than the AGM in my 991 which is almost 4 yrs old! Thanks in advance for this info

Jim

Antigravity

Hey Jim I know some of the M3s and M5s had lithium ... didn't know they put it in the M4 of a few years ago.

I think you looking quite good at 8-10 years since you already have 5 years. So that is cool. Ultimately this will depend on the cells they use, the BMS protection system in that battery, and how often it is used, but I would be very optimistic you will get that range for sure. And a 70Ah Lithium is a real beast... some serious power and Amp Hours there.

So don't worry about it and run it till it dies. DO NOT let them tell you you need a NEW Battery until it actually won't start your car. These Dealers know NOTHING about Lithium, and they are flat out liars in regards to batteries 90% of the time and looking for sales only. Again don't trust the dealer.... just wait till that battery won't start your car and you've made sure it isn't some other issue. If you battery is resting at about 13.2v and starting the car fine.... it is absolutely fine. That's all there is to it. When a Lithium goes bad it really just stops turning the motor over effectively, and it won't hold a charge long. Its pretty obvious. So that is why I say don't trust them. Last keep in mind BMWs are super smart... so it might start to give you flags and such if it thinks it going bad. Most actually register the battery on the BMWs when you put them in at the Dealer so hopefully their system doesn't try to create false flags in another few years. I don't trust what they are doing now with the computers...

Also keep doing what your doing if you already got 5 years in. Don't change anything you have been doing. No reason to introduce something new when you are getting good life on your battery.

On BMWs we see ALOT more parasitic drain... meaning they do tend to discharge batteries faster than the Porshes... the 991s really put all their systems to sleep so well. The BMWs seem to use more energy so that is why they probably went with such a large Lithium Battery. But don't worry about our battery replacing yours now.... if you get a couple years more maybe lithium will be cheaper then. But I would stick with 40Ah or above in the BMWs since they have a higher parasitic draw.

96redLT4

^^Thanks for the info Scott. I did order one of your MicroStart units as a back up.

J

Greg D.

I saw an antigravity stand at Laguna seca a while back. Not sure if it was official or reseller... I picked one up to weigh it and was blown away by how light it was (especially after having replaced mine with another AGM and damn near thrown my back out in the process) . Next time my battery goes bad I'm *definitely* picking one up... I read that you needed a specific charger/maintainer (i have a regular Ctek - probably the wrong model?) - the only thing I did not read about was if you needed to do the mythical computer reset that has been questioned a lot, for an antigravity battery, or will it tolerate the default charge mode from the car ? .

Antigravity

Hi Greg, I think it was touched on a little earlier in the thread but the just of it is you do not have to reprogram the PIWIS to use our battery. The existing profile will provide a completely satisfactory charge for lithium. It may be something to consider if you using in track/race applications but again not necessary to do so.