Electrathon America Forum

meangreen · teacher / board member

A rule or a suggestion?

Archer321 · Senior Member

I agree with your suggestion. Lithium vs lead-acid is like bringing a sword to a knife fight. Pretty similar but the difference is significant.

Brendan_Smith · Veteran Member

Another option might be to drive towards enabling additional ballast to bring the Experimental cars up to equivalent mass to a Standard class. You've already got maximum masses for advanced battery tech in the rules, so you'd just need to subtract those from the 73lb upper limit for lead acid and you have your additional ballast weight.
Should then be no discernible advantage for bringing those cars into the Open class as they have the same power density, albeit that they can choose where to place their ballast.
Potential danger, however, comes from locating and securing said ballast. It's one thing to add a little to increase the driver's weight to the minimum, but it's another to add large masses to the car. Scrutineers would need to be vigilant to ensure safe application to said cars, but luckily would only need to examine one or two cars only (otherwise they have a class!)

An example of when it can go wrong when ballast is just lumped in. See the end of the below.
www.channel4.com/programmes/speed-with-guy-martin/on-demand/58642-004

meangreen · teacher / board member

Adding ballast would take away the weight advantage, but Lithium batteries have a different curve on their charge/discharge cycle. Lead acid batteries lose their power gradually over the course of a race. Lithiums have a fairly flat power curve; they run at the same level until they reach their bottom limit and then just quit. Once a team figures out the optimum "life cycle to gear ratio" combination, the lead acid cars are left in the dust. There is really no way to equalize the two types of batteries. The bottom line is Experimental and Standard battery cars should not be combined in one class.

I couldn't get the link to work. Got the opening picture, but the video wouldn't play. Anyway, I once had to put 90 pounds of ballast in a car because the driver was a petite little girl who weighed 91 pounds. I bolted one of my old stock car weights (a 50 pound lead bar) to the front axle with 1/2 inch bolts. For the rest we used two 20 pound dumbbell weights attached to the bottom of the roll bar with the big 100 pound zip ties, two on each weight. Yes, loose ballast could potentially be very dangerous; it has to be properly secured.

dmorgan · Member

So what's your suggestion, Jim? Yes, I agree on the separate class but what about the weight difference? Right now in Georgia, we have only 2 cars running Lithium batteries. Both cars are new this year and they've been working out bugs so it hasn't been much of an issue. I know both will be at our race in a couple of weeks plus the FL car you mentioned. Looks like I'll need three sets of trophies! These are things that need to be hashed out before the Handbook is rewritten for next year. As our organization grows, and it is, the more things we get settled, the less race day problems.

ProEV · Senior Member

Jim,

Good point, but one that probably does not require any modifications to the rules. The rule book states (on page 29) "Electrathon Classes are created only for the purpose of awarding prizes" and that there are SIX MAIN CATEGORIES THAT COMPETE SEPARATELY EVEN IF IN THEY ARE IN THE SAME RACE. They are HS standard, HS solar, HS Advanced, Open standard, Open solar, Open Advanced. So it seems to me that Open standard and Open Advanced can not be put together.

There were three Open standard cars entered (even if one did not complete any laps) and only two open advanced battery. So, I think I should hand over the Open Trophy to Steve, Steve should hand over second place to Rodney and Rodney should pass his to Pensacola State College and the official records should be modified to seperate the classes and show the correct results.

ProEV is first in Open Advanced and USF is second. Our class is not sanctioned but there does not seem to be any defination of what that means. I assume that we are still eligible for the overall Trophy, so I will hang on to that aww .

ProEV · Senior Member

Archer321 wrote:
I agree with your suggestion. Lithium vs lead-acid is like bringing a sword to a knife fight. Pretty similar but the difference is significant.

Steve,

Lithium's biggest advantage is being 50 pounds lighter. This means less energy to accelerate and less mass allows the car to carry more speed through traction limited corners. This is a big help in parking lot courses but I do not think it really comes into play on big banked ovals like Five Flags. Everyone accelerate once at the start. Because of the banking, no one has to slow for the corners. There is a small theoretical advantage in rolling resistance by the 17 pound less load on the each wheel's bearings that would be hard to quantify.

I first ran Five Flag's in 2012 in the same car powered by lead acid. I ran 63 laps in the first race and 68 laps in the second race. This year with lithium, I ran 64 laps and 68 laps. I was too aggressive in the first race and too conservative in the second race. So the record for the most laps in one hour is still held by Pensacola HS at 69 laps with lead acid.

ProEV · Senior Member

Brendan_Smith wrote:
Another option might be to drive towards enabling additional ballast to bring the Experimental cars up to equivalent mass to a Standard class.

Brendan,

My personal opinion is that this would be a mistake. We want to encourage teams to experiment with new batteries. Advanced batteries are cheaper, perhaps longer lasting, and more relevant to electric transportation. No one is using lead acid for traction packs except golf carts. It is great not to have to lug around all that lead!

"The Advanced Battery Class is intended to foster experimentation with

newer battery technologies that offer higher energy density than lead-acid,

and reflect the rapidly expanding availability and usage in the transportation

industry."

But what we do not want to do is ruin electrathon by changing too rapidly. The standard lead acid car teaches the fundamentals and is an excellent teaching tool. So it is good to have both.

ProEV · Senior Member

dmorgan wrote:
So what's your suggestion, Jim? Yes, I agree on the separate class but what about the weight difference? Right now in Georgia, we have only 2 cars running Lithium batteries. Both cars are new this year and they've been working out bugs so it hasn't been much of an issue. I know both will be at our race in a couple of weeks plus the FL car you mentioned. Looks like I'll need three sets of trophies!

Don,

Will the two Lithium cars be running this weekend? I will be there, so that would make three. I am not sure what USF's plan is.

I don'the need to run for trophies, just some of those excellent peaches aww .

Nitoragro · Senior Member

I am talking with USF (Another lithium car) they will be in Quitman and Leeds for the races

meangreen · teacher / board member

Hi Cliff,
First, let me say that I don't think you or anybody else should be handing your trophies "down the line". You ran a race according to the rules as they were interpreted and applied by the race organizers. Therefore, you won those awards fair and square.

My contention is that the paragraph on page 29 is not clear. It gives some advice and permission for ADDING classes, but says nothing about COMBINING classes. You are correct in assuming that Standard and Advanced are not supposed to be put together. Nevertheless, race organizers assume that if you can add classes then it's OK to combine classes - not so. There is no provision for combining classes and that's where the problems may occur. If there was no difference in the performance of different types of batteries there would be no need for different battery classes. We could just impose a minimum weight limit for all the cars and "run what ya brung". However, I agree with you that such action would likely discourage experimentation and education. This very topic was discussed briefly at Wednesday's (4/26) board meeting. Mike Hodgert indicated that combining different battery classes was never intended to be allowed, but the wording on page 29 is vague and possibly incomplete. It may be more clearly defined when the new rule book is published.

On the tight parking lot courses is where the advantage of the Advanced Battery cars is evident. Looking through the lap counts in Florida races so far this season, comparing the highest finishing Advanced Battery car to the highest finishing Standard Battery car in each race, the Advanced cars complete from 8 to 13 more laps per race. The reduced weight may be part of the advantage, but I know when my power is starting to wane in the closing minutes of a race, the Advanced Battery cars are still clicking off laps at full speed.

Don - Yes, you probably need a set of trophies for Advanced Battery class (and maybe some extra peaches). Other race organizers take heed - If there are Advanced Battery cars running in your events you need to be prepared with a set of awards for them. Also, a "First Overall" trophy isn't a bad idea (or possibly 1st, 2nd and 3rd). If there aren't enough cars in a class to be "sanctioned", they can still compete for Overall.

Archer - Your comment pretty well puts it in perspective.

Archer321 · Senior Member

ProEV wrote:
Archer321 wrote:
I agree with your suggestion. Lithium vs lead-acid is like bringing a sword to a knife fight. Pretty similar but the difference is significant.
Steve,
Lithium's biggest advantage is being 50 pounds lighter. This means less energy to accelerate and less mass allows the car to carry more speed through traction limited corners. This is a big help in parking lot courses but I do not think it really comes into play on big banked ovals like Five Flags. Everyone accelerate once at the start. Because of the banking, no one has to slow for the corners. There is a small theoretical advantage in rolling resistance by the 17 pound less load on the each wheel's bearings that would be hard to quantify.
I first ran Five Flag's in 2012 in the same car powered by lead acid. I ran 63 laps in the first race and 68 laps in the second race. This year with lithium, I ran 64 laps and 68 laps. I was too aggressive in the first race and too conservative in the second race. So the record for the most laps in one hour is still held by Pensacola HS at 69 laps with lead acid.

Cliff,

I think you may be forgetting the difference in discharge characteristics between the two battery chemistries.

I'm sure you are aware of how much slower lead-acid gives up it's power than does lithium ion.

Also, I know the differing battery weight allowances for differing chemistries was designed to keep overall pack capacities similar, but how similar are they really? With all the advances in lithium batteries since the weight guidelines were drawn up has the capacity of a 15 lbs pack grown?

How many amps does your pack support for an hour?

I'm certainly not suggesting that those weight allowances be changed. I feel the different vehicle classes do a fine job of keeping the playing field level. My point is just that significant differences exist between lead-acid and lithium ion. But you have given me something to aspire to... trying to duplicate lithium performance on lead-acid.

You keep racing Cliff, and I'll keep chasing you.

Brendan_Smith · Veteran Member

Hi Cliff,
Sorry, I meant that the battery techs could be balanced by ballast only if/when the experimental class had insufficient entries. No ballast if the class runs, the playing field is then already level.

A "First Overall" trophy has pretty good merit; that way, if you have one or two Experimental class cars that are good enough, they can compete for the overall win without getting in the way of the Standard cars (nor upsetting their points system), and if a third car turns up they have their own class anyway.

Also, the weight stipulation in the rules is possibly counter-intuitive when discussing particularly advanced battery tech. The "maximum" allowable battery mass stops extra storage, which should be eliminated by the 1kW limit anyway.
For instance, the battery packs I'm planning to run come to 9.2kg (a little over 20lb 4oz) for 960Wh of rated energy using LiFePO4. The mandated maximum battery mass for that chemistry is 29lb, but I've got close to the energy limit for an 8.5lb discount. In this situation, it would make sense to me that I would need to carry some missing mass as ballast, to level the field, just like they do in the British Touring Car Championship and other production-based race series...

Nitoragro · Senior Member

Brendan,
About that 8.5lbs of "missing battery" weight, I don't think that you need to ballast for that assuming you have other advanced battery cars. I run 3 cars, One runs 72 lbs of batteries, another runs 69 lbs, the 3rd runs 52 lbs. That advantage anyone else I compete against can have. Any lead acid car can have this same thing, it would be like having an aluminum car or a lighter motor, or a driver that's not 200 lbs. However if you were the only advanced battery class and were 52 lbs underweight then I could see using ballast.

Don and Cliff,
I just heard from Charlie that the Electrocutioners (2 or 3 lithium cars) will not be at Quitman or Leeds. So I think it will only be Cliff and USF running Advanced.

Steve,
This is what Cliff (ProEV) put in one of his earlier post about battery capacity
Rhino Lithium-Polymer pack rated at 972 Watt hours/tested at 1,100+ and less than 15 lbs cost around $350 delivered. This is around the same cost as a 840 normal/1008+ tested (Dave Cloud reported) Watt hour pack Optimas. And the rules say "Maximum output of any battery combination used may not exceed a one-hour rating of one kilowatt/hour according to the manufacturer's data." So the 972 rated is legal even though the tested capacity is more.

I think the easiest way to fix this problem of how to judge lead acid vs lithium against each other when the classes are not large enough is communication. The teams and the race steward should have gotten together before the race and decided together how the trophies/award will be handed out. If they did this I think it could have solved some problems that could happen.

All this sounds like is making advanced batteries worse so they can compete against lead acid "fairly." And I think that this is being looked at incorrectly. One thing about moving the experimental is it is an experiment, not everyone is doing it, in fact very few people do (as of now). And that is something I bet everyone who runs advanced batteries knows. When teams run advanced batteries they should know most people will not be racing them, and they might not have competition.

This discrepancy between Advanced and Lead Acid can only happen when there are 1 or 2 advanced cars. If this happens then I would say we need to look at one thing, is it fair to directly compare advanced vs Lead Acid cars? Probably not. While there is not a Advanced class (as of now) for a race with 1 or 2 Advanced cars its just not fair they be put in the same class as Lead Acid (like how it was in Pensacola). How the rankings should work in my opinion for larger races like this is 1st, 2nd, 3rd best Lead Acid cars, 1st, 2nd, 3rd, best Advanced cars, and 1st, 2nd, 3rd best overall Electrathon car since they are ALL Electrathon cars. While sometimes there is not 3 cars in the advanced battery class then that class should just not exist and they should compete for best overall Electrathon car award. However sometimes there is no best overall awards then the experimental just won't get a trophy, and that is something they should understand, and that's how the rules are set as now.

In Tampa we have the opposite of this problem sometimes, where we have 3+ advanced cars and only 1 or 2 Lead Acid cars. What the race organizers do is have 3 sets of 1st-3rd trophies, high school, open lead acid, and open advanced. And they always have these 9 trophies so every now and then a 3rd place open lead acid car trophy is never awarded. And this solves the problem for us.