Jed,
> Note that the Prius now uses NiMH batteries, no lead-acid. When I said "advanced batteries are cheaper over the life of the car," I meant the NiMH ones they now use.
What is the performance of these in AH/Kg for
comparative purposes?
Plus.... Don't forget two other advancements -
ultracaps and ultraconductors.
Here are some numbers form web
sources last year. The ultracap may be better now.
For an advanced SLA - Lead Acid-Battery: 12V
13AH 4200g
For the UltraCap: 350 Farad 2.5V 60g
For the UltraCap: 350 Farad 2.5V 60g
ERGO
SLA Battery: 13AH / 4.3Kg = 3.02AH/Kg
let's say a performance index of 3
UltraCap: Q=CV => 350F * 2.5V = 875 Coulombs 1 Amp=1 Coulomb/Sec => 1 AmpHour = 3600 Coulombs => 875 / 3600 = 0.243AH 0.243AH / .06Kg = 4.05AH/Kg
UltraCap: Q=CV => 350F * 2.5V = 875 Coulombs 1 Amp=1 Coulomb/Sec => 1 AmpHour = 3600 Coulombs => 875 / 3600 = 0.243AH 0.243AH / .06Kg = 4.05AH/Kg
let's say a performance index of 4
That is a third better now. The Ultraconductor of
MPI, when used in a capacitive mode may double the SLA, according to Mark
Goldes. That would be ~6 or hopefully higher.
Of course the vapor-ware hydrino battery is
supposed to be about 50...??
Where does NiMH fit in?
The nice thing about UltraCaps, according to these sources who have actually used them, is that they are in production now, and the cost is dropping but still high and you can charge them VERY fast !! TheSealed Lead Acid (SLA) battery, in comparison, takes a LONG time to charge (4A max charge rate). This can be important in certain hybrid designs.
It is a real mystery why Apple did not go with ultracaps for the nano
- as it takes a couple of hours to charge. Knowing S. Jobs, this is probably
going to be announced next week... ;-)
Jones
