ttxgp won by agni motors

maydaverave

10 kW
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Jan 13, 2009
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I saw that a uk build powered by agni motors won the ttxgp. Was this jozzbikes or another member or former member of this forum?
 
I think we are near a tipping point in US society. I am seeing more and more references in the mainstream media about E-bikes, E-scoots, and E-moto's. They are still not well-known by the majority of the population, but once they become a hot story, we will see more pages and air-time on them.

It is wise for Agni to invest in making an early big splash. There's enough pie for everyone, but any success Agni enjoys now is good for all EV parts suppliers.
 
It turns out that the battery pack used by Agni motors was smaller than originally intended. They cut things really close. Here's a message Cedric Lynch posted recently on the Thundersky yahoo forum:

I do like the Kokam cells for racing because of
their excellent energy density at high discharge rates and their very low
internal resistance. We got 100% of the cells' rated capacity (42 x 70AH
cells in series-parallel for about 80V 140AH) when taking it all out in 26
minutes, and there was still a little left. For applications where the
highest energy density is not crucial I would still tend to prefer Thunder
Sky because (1) they are cheaper (2) they are much easier to install and
(3) in the case of cells made after about 2005 they have longer life, which
is very important to the economics of running an electric vehicle.
One team in the TTXGP did use Thunder Sky LFP cells which performed well.
Their installed capacity (21 x 90AH cells, about 6 KWH) was a bit too low
for a top result but their bike did get to the finish.
 
Cedric Lynch said:
(42 x 70AH
cells in series-parallel for about 80V 140AH) when taking it all out in 26
minutes, and there was still a little left....

Cool, I read the same recently somewhere else. They planned on 63 cells but could not fit them all in.

If the race is run again at the IOM for one lap, I'd be surprised if any runs less energy then Team Agni (~11kWh). I'd like to see the teams packge 15-20+kWh in the bikes :mrgreen:
 
It's interesting that Cedric mentions ease of installation as one of the main benefits of prismatic cells such as Thundersky. I'm learning myself that fitting smaller cylindrical cells on a motorbike involves a lot more thought and effort than I'd imagined.

42 x 70Ah = 10.8 kWh, so over a race lasting just under half an hour the Agni bike averaged around 20kW for an average speed of 87 mph.
Average battery current 250A.
 
Malcolm said:
42 x 70Ah = 10.8 kWh, so over a race lasting just under half an hour the Agni bike averaged around 20kW for an average speed of 87 mph.
Average battery current 250A.

I wish there was telemetry data coming off the bikes, I'd like to see power, current, voltage & Watt-hours displayed on screen during TV race coverage 8)

I think current would have been jumping all over the place across the IOM mountain course with all the turns, hills & straights. It would be interesting to see how power was used and where it was conserved. And, how this compares to a petrol bike.
 
My hope is that Agni motors become popular enough to greatly expand production, so they become less expensive and more readily available. Isn't that the purpose of a sponsorship. While they're at it, how about a version that maximizes continuous output in a package of half the weight specifically for ebikes. For the icing on the cake, let's be greedy and add in highly efficient and lightweight 2 speed transmissions for both the new and original motors.

On a separate topic, the top performance guys still seem to use brushed motors. In daily normal use how often do the brushes need attention with these Agni's. How much does bi-directional use reduce brush life?

John
 
We worked the numbers out in another thread, and his ending voltage was 3.5/cell. He still had about 30% of the energy left in the pack after the race.

That means when Kokam calls them 70Ah cells, it's like when Hobbycity calls it a 5Ah lipo cell, and yet you pull 6.5Ah out of it after break-in.

It's also interesting that Kokam rates the cells to be cycled clear down to 2.7v. Don't try that with LiCo cells.
 
liveforphysics said:
We worked the numbers out in another thread, and his ending voltage was 3.5/cell. He still had about 30% of the energy left in the pack after the race.

That means when Kokam calls them 70Ah cells, it's like when Hobbycity calls it a 5Ah lipo cell, and yet you pull 6.5Ah out of it after break-in.

It's also interesting that Kokam rates the cells to be cycled clear down to 2.7v. Don't try that with LiCo cells.

I had given you the wrong info, they only managed to fit in 42 cells, not 63 as they had originally published. That means they had 1/3 less energy on board then we had assumed. It seems that they did in fact cut it close. A custom frame would have enabled more cells to be fitted I suspect, but I'd still argue that giving the rider a bike chassis he was familiar was very important and worth the sacrifice.
 
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