> On Oct 8, 2015, at 11:56 AM, Anthony Jackson <xxxxxx@iii.com> wrote:
>
> From: xxxxxx@shadowgard.com
>
>> Another problem is that as batteries sapproach (or pass) the energy density of gasoline, they get dangerous. A
>> battery fire with batteries that powerful is a *really* bad thing. So are shorts and the like.
>
> Actually, they get plenty dangerous long before that; gasoline's effective energy density is increased (by a factor of 4-5) by the fact that it uses atmospheric oxygen (which isn't really an option for most battery designs, though there are some unrechargeable cells that do so), and if you store oxidizer along with gasoline the result is ridiculously dangerous. Fortunately, we don't really need to match the energy density of gasoline, because the battery is replacing the engine as well as the gas tank (the electric motors are more the equivalent of the transmission).

Also you get greater efficiency and performance if you move the motors to the drive wheels; infinitely variable traction control and zero transmission losses, more so if you go with AWD. A lot of current designs eschew this in favor of a more typical electric motor:transmission but that’s mainly to leverage existing vehicle stock and parts. I was a little shocked to find I can buy the kit online now: <http://tzquanshun.en.alibaba.com/product/60044746306-800339755/273_8_8kW_Hub_Motor_Electric_Hybrid_Car_Conversion_kit.html>

Sadly this is a wholesaler, I don’t know how much it costs per kit…

I’d also look a wee bit askance at those controllers; they look a bit small for 8KW…

--
Bruce Johnson
University of Arizona
College of Pharmacy
Information Technology Group

Institutions do not have opinions, merely customs