Testing on the ebike in Australia is underway with the first pack, Lead Acid, being the star of the show.  Many people have asked, "Why bother?, we already know that a lithium pack will power an e-bike very well!" 

    Good point! But we are not trying to prove something we already know.  The purpose of the test is to uncover a mystery.  Where does the unexplained extra range come from when using lithium?

   During track tests in Virginia, and to a lesser extent in SC, it was discovered that there was range added to the vehicle that was not expected based upon the normal formula of KWh per mile.  Some of the extra range could be explained as energy savings due to shedding weight in the battery packs themselves.  But that did not explain all of the extra energy that seemed to appear during testing.

   In a test vehicle you save 25% of it's curb weight by changing from LA to Li battery packs.  That is a substantial amount of weight.  On an e-bike the greater weight is in the bike and rider, so the amount of weight shed is much smaller as a percentage of the total weight.  So, testing Li packs on an e-bike removes one of the variables, the weight dropped from LA to Li.  The fewer the variables in an equation, the easier it is to solve.

   It is our opinion that the extra gain in range and power from LA to Li packs is due to the difference in Peukert's effect in relationship to the two different technologies.  Lithium has less loss in delivery than LA, so that would account for the difference in energy above and beyond that saved in shedding weight.  In any case it will be an interesting experiment.

   The testing is being performed by Rob Leviston in Victoria, Australia.  Updates will be provided as they come in.  A second chart will be posted when the pack change to Li occurs.
   

   Data from the packs, motor, and controller are obtained from equipment similar to the units on the Accent, Tucson, and Ranger.  The data is displayed in raw form rather than being converted by our on board computer to a more user friendly "Available Range", "Charge Remaining" format.

   The format of the data on the chart is self explanatory, with the exception of the column V Sag.  This actually is Voltage sag, or drop in voltage due to the load being applied.  It is an indication that the LA battery is not designed to provide the current required to run the bike, even though the specs would indicate that it is capable.  The load of 1C is actually dropping the potential voltage by 10% across the two 12VDC packs.  This is somewhat typical of LA chemistry.

   Li will not exhibit this same "Sag" as it is quite comfortable supplying 11C.  A couple of other things to note are in the controllers.  It is quite common for controllers to heat up during operation.  Some of the controllers on our LA test vehicles got very hot, so hot that you could not touch them.  These same controllers did not get anywhere near as hot when the packs were changed to Lithium.  This would indicate that the impedence match was much better.

   The percentage of gain in our test vehicles was better than 50% more range just by switching from LA to Lithium packs of the exact same size.  Again, some of this could be attributed to the weight that was shed, but the rest....well that is part of the mystery that we hope to solve with these ebike tests.