Hey Bad. Sorry for the delay, but it is finally here .... .and long
There are four (4) aspects of the battery and its use that need to be understood and factored in for this discussion. They are:
1) The maximum continuous discharge rate specification of the cell
2) The internal resistance of the cell
3) The application of the cell
4) The cell lithium ion chemistry
The cell ratings are based on a continuous discharge. The application is intermittent duty, by its nature not continuous, so a cell can be intermittently be pushed somewhat harder than its continuous rating in this type of application. The Provari when supplying its maximum output power (14.5 Watts) will need to draw a maximum average current from the cell of 5.2 amps. While it is true that the pulse current can be as high as 9 amps, the duration of these pulse currents is less than 10 microseconds and is not as important as the total average current drawn.
The 5.2 amps is when the cell is at end of charge and the output is adjusted to maximum power out, so it is an absolute worst case situation.
This situation is important because any manufacturer of a high quality
device needs to account for the worst case conditions his product will be exposed to in its application.
When compared to the 6 amp continuous rating of the AW18350 cell it passes with some acceptable margin. The AW18490 and AW18650 have even better margins.
BUT just as important, is the safer lithium ion chemistry and very low internal resistance of the AW cells. Other lithium-ion chemistry and higher internal resistance cells will not perform to the level of the AW cells and therefore reduce the overall experience when used. The cost of these other cells when comparing their performance and safety are just not worth it.
There are cells that claim to have the same or better capacity as the AW cell BUT their internal resistance is inferior. If the cell has a higher internal resistance it will drop more voltage when current is taken out and as a result the ProVari will indicate it is at end of charge when it could have a significant amount of capacity remaining.
What good is this capacity if it cannot be utilized by the ProVari? It is of NO use, so why use it?
We will ONLY recommend cells that our engineering tests show will allow the ProVari to perform at its best.
