Quote:
Originally Posted by sportcoupe
A Trojan t-105 is 225AH at a 20 hour rate. That is published. They even publish 10 hour and 5 hour rates which have much less AH. Hardly no manufacture published their 1 hour rates, that's the one that seperates the men from the boys.
You have to compare apples to apples. If a lithium battery has a 10AH spec you have to know at what rate it's taken at to compare to a Trojan 20 hour rate of 225AH.
|
The variance in Amp-Hours at different discharge rates is due to the Peukert Effect and the Peukert Number for Lithium batteries varies with the chemistry.
The Peukert Number for the type of Lithium battery (Lithium Cobalt Oxide)that caused the grounding of Boeing 787 Dreamliners, is very close to 1, so varying the discharge rate does not significantly vary the AH capacity. On the other hand, the Lithium batteries linked to (Lithium Iron Phosphate) do have a Peukert Number >1, so the AH will vary with discharge rate.
However, manufacturers tend to display the products in a favorable light, so I'll stick with my assumption that a 100AH battery will have less run-time than a 225AH battery.
It may not be less than half as I originally said, but it is betting odds that it will be less.
As for reduced performance, I might have been unfair because I overlooked the fact the Lithium batteries have a nearly flat discharge curve while the terminal voltage of Lead-Acid batteries decreases as discharge rate increases. Due to that electro-chemical attribute, a 100AH 36V Lithium battery pack might be able to produce the same amps at the same volts during acceleration and hill climbing as a 225AH 36V Lead-Acid battery pack.
Hopefully, at some point in the near future, Lithium battery manufacturers will publish more meaningful specs on their products and some valid comparisons can be made.
