Tony from Voltphreaks here, just want to add, the 14 pound Voltphreaks VPR-S40P model isn't what is recommended for Porsche's. The model we recommend is the VPH750. It can still start the car in cold weather, and you don't need to leave it on a trickle charger (if you drive the car at least every 2 weeks or so), even though it has only 14Ah. The VPH750 is cheaper than the Porsche OEM option, though still much more expensive than a lead-acid battery. The VPH750 is comparable to 20 to 30 pound lead-acid batteries.
Based on your observations below for your situation, the VPH750 should last about 5 days, or so, but most applications with the VPH750 results in the battery lasting 2 to 3 weeks. In any case, you don't need jumper cables with any of the Voltphreaks batteries because they will shut off before the battery is completely drained, leaving enough power to still start the car by pushing a button to turn the battery back on. Though you can still carry jumper cables to give other cars a jump.
The VPR-S40P is mainly for applications where you need the battery to run the car a long time when the alternator fails (ALMS, Rally, etc), though of course it would work fine in a Porsche. Risi Competizione ran a single VPR-S40P in their 430GT to win the 24 Hours of Le Mans in France this year!
- Tony (voltphreaks.com)
Quote:
Originally Posted by NJ-GT
The water cooled cars have a lot of parasite loads (static loads) in the electrical system. These cars need batteries with enough reserve and capacity.
- The stock Moll has a capacity of 70 Ah and a reserve of 115 minutes.
- The common replacement (and lighter) Optima Red 35/75 has a capacity of 44Ah and a reserve of 90 minutes.
We cannot compare a Braille or Odyssey to a Li-Ion battery. In the warm California weather, my 11 lbs Braille needed to be plugged permanently to a trickle charger in the garage. Things got better with the 15 lbs Braille.
At a warm track day I had to unplug the engine cooling fan with the car sitting in the garage, otherwise the Braille would drain out and the car won't start.
A 11 lbs Braille only has 15Ah and 25 minutes of capacity. A 15 lbs Braille has 21Ah and 35 minutes of capacity, still not enough. When I was using my RS with a Braille, I was carrying a jump starter as part of my tools, because more than once the car ran out of juice. My Spec Boxster drained a brand new carbon Braille (15.5 lbs) in 6 days just sitting in the garage.
A 14 lbs Lithium battery (volthpreaks) has a capacity of 48Ah and 100 minutes, better than an Optima Red Top. I already ran an Optima red top in my GT3, and I didn't need to carry a jump starter.
For some, 22 lbs could sound like negligible weight, but consider the location of the stock battery. Also, it is cheaper (per pound) than lighter wheels, a lighter flywheel, PCCB, or carbon body parts.
I'm quite sure that Porsche went through enough testing with this battery before pioneering such technology into mass produced vehicles.
I hope they offer the option in all the Porsche road cars (except Panamera and Cayenne, the anti-thesis of lighter cars).
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