I'm seeing a lot of conflicting information on which batteries should work best. I am going to buy two new sets this year and am leaning towards the yellows (recommended by Optima for both performance and longevity), but have seen some conflicting information and don't want to 'waste' 800 bucks.
What are you doing this year?
electrathon said
Mar 11, 2010
We are running red tops. We have not done any specific testing, but I feel that the red tops can be fully drained in an hour and the yellow top will have more trouble fully draining them in the allotted time. If the races were 4 hours long, I would likely run them.
If you are looking to try differant things, one 75/25 and one 78 series battery would have a lot more output than any two 75/25 series batteries. Be carefull with the weight, you will need to weigh them in the store and find the lighter ones.
Anonymous said
Mar 29, 2010
Go to the Optima Battery web site. They have the weights of all their batteries listed, I think, under. Technical Data. Red, Yellow, Blue are all there.
electrathon said
Mar 29, 2010
The published weights are only an approximation, they can be off a lot. If you are using "approved" batteries listed in the rulebook, you do not have to weigh in your batteries. If you are using other batteries, they must pass the scale test.
Cent-ECAR-man said
May 3, 2010
We were just talking about this and i think the top cars in the standing are all using red tops :) if that tells ya anything.
iguy said
May 3, 2010
Nathan McCaw is using the yellow tops and I believe is in 3rd overall.
Cent-ECAR-man said
May 4, 2010
well i stand corrected, gears ratio's also come into play here :)
bd64 said
Jun 2, 2010
Let's try to answer one question about Yellow Top batteries.
Do the Yellow Top batteries provide the 8% energy increase for this application as per Interstate Battery engineers?
ShannonCloud said
Jun 2, 2010
My dad, Dave, Did testing on yellows vs reds and found that the yellows are actually not as efficient/good for our purposes. I can post numbers later...
electrathon said
Jun 2, 2010
bd64 wrote:
Let's try to answer one question about Yellow Top batteries.
Do the Yellow Top batteries provide the 8% energy increase for this application as per Interstate Battery engineers?
I think the energy is in there, just not able to get it all out in an hour.
Shannon, if Dave has data it would be great if you would post it.
Anonymous said
Jun 6, 2010
Our season here in Tampa is basicly over and we ran last year and this with Red tops in both of our cars.. One of the other high school teams, also and Auto Tech Program, has used Yellow tops since last Dec. I have not been impressed with their performance. Their car is a clone of ours, we helped them get started, and they have had two DNFs because of batteries and one Black Flag due to batteries. One race they had a bad battery at the start and had to swith out before they could even get off of the start line. We have yet to have a bad result due to batteries or electrical problems. We are using Red Tops and Kelly controlers. We ran through a bunch of thumb throttles before swithching to twist grips.
mhodgertt said
Jun 6, 2010
I ran Yellow tops all season long in my car along with several of my students. I found that I had to drive the yellow tops a little different. When you start out they get down to a combined 22.? volts a lot sooner than the red tops did but they stay there for a very long time. If you keep pushing them they will drop down below 22.0 and then lower around 45-50 minutes and you will start to slow down. But I think I found a way to keep them going and get more out them then the red tops. Since I don't use any fancy monitoring equipment (simple Harbor Freight volt and amp meters) I watched by volt meter closely. When it got down to about 22.2 volts I would 'take a lap off' and coast more and be sure not to push the amps up at all. After that lap I was up to 23.? something again under power pulling normal amps. I would then race hard for a while until the voltage dropped again to about 22.2 and do it again. With this method I think I might have actually gotten more out of my yellow tops than the red tops last year. When driving them hard I could push a little more than I could with the red tops. The last two race I raced this year I went farther than I did the year before. Again without any specific monitoring systems this is just a guess but I will see how I do this summer and fall in our last races. I usually had to take my first lap off at about 30-40 minutes and again around 40-50 and maybe a partial lap off at around 50-55 if the track had a lot of slow traffic our a very tight corner.
I will be honest--If I can get about the same distance out of these batteries as the red tops and they last me for several race seasons I will consider it a win. The red tops seemed to only last us in top form for about 17-20 races before they started to not last the full hour. In the NW we have about 15 days of racing a year so we got one good season out of them before we had to replace them. Those on my team that tried to use last year's batteries found out that part way through this race season their batteries that made 10-15 races last year started to die before the full hour. With 20 cars a year and 2 batteries per car I can not afford to buy 40 batteries each year at over $5000. I also think that is not what Electrathon is about--not a very green system to replace that many batteries.
Mike
ShannonCloud said
Jun 10, 2010
Testing results at a 50 amp rate:
reds: 42+ amp hours
Yellows:35 amp hours
bd64 said
Jun 10, 2010
Thanks, Will you be at KC this year?
ShannonCloud said
Jun 12, 2010
bd64 wrote:
Thanks, Will you be at KC this year?
well i have school, but my dad wants to go, he has thoughts of a new car.
bd64 said
Jun 16, 2010
New York Electrathon has some interesting data posted at
-- Edited by bd64 on Wednesday 16th of June 2010 12:10:20 PM
Zaine Stapleton said
Jul 20, 2010
I used yellow tops at da Vinci days this year to see how they did on the short track rally courses for the two days. The only other time I used yellows was at PIR on the long track, but I couldn't compare performance since it was mostly constant throttle the entire time. I think I got more out of them compared to red tops. Plus, they seemed to be putting out the same power each day, besides the flat the second day. I know the first days race results, the top four cars in the student class were all running yellow tops. The second day with the overall results from the two day race, all the cars from second to sixth place were running yellow tops. The winner ran with yellows the first day, then used reds the next.
Good job Nathan, you deserved the win! :D
churd said
Sep 18, 2010
Testing results at a 50 amp rate:
reds: 42+ amp hours Yellows:35 amp hours
What does this data mean? Could you please elaborate?
Optima says 44 for red, 48 for yellows at C20. Data sheet HERE
-- Edited by churd on Saturday 18th of September 2010 01:56:19 AM
Zaine Stapleton said
Sep 18, 2010
The results shown for Reds: 42+ and Yellows: 35 is for amp hours. The specs that Optima batteries is showing has little meaning for electrathon racing. For example, the 48 amp hours for Optima Yellow tops is tested at a rate of 20 amps for 5 hours, or 5 amps at 20 hours. Obviously, a lot of us are not going at a 20 amp rate for a race, usually it a 36-50 amp rate so the drivers will complete the hour long race at a consistent speed for the allowed time.
Kirk Swaney explains further of what the specifications for the batteries mean on his website.
Below is a post I made after doing some testing on yellovs red tops. The full discussion, including full downloads of all data and testing procedures can be found here:
From carefully analyzing the data in the previous post (and summarized above) we have drawn the following conclusions:
1. All batteries are NOT created equal. From the factory, the batteries can have a C1 rating that can vary by up to 3-4 Ahrs from battery to battery. Choose wisely; if you have a choice.
2. Both Reds & Yellows are green directly from the factory; They do NOT hold an optimal charge, and get better over time. (see data in the previous post)
3. Both Reds & Yellows improve with age; to a point. What is that point? We don't know, as we haven't reached it yet. It could be as many as 10 to 15 charge/discharge cycles for the yellow tops. (Thanks Dave!)
4. How you charge the batteries does have an effect on the final Ahr rating, but when charged similarly, the yellows and the reds overall differ by less than 1Ahr at a C1 rating.
5. The discharge curves for the two diferent batteries have almost exactly the same profiles. See the attached files as well as the graph below.
In the chart above, the red & green lines represent the factory yellow tops, and the black & blue the factory red tops. As you can see the curves are exactly the same with the C1 Ahr rating averages differ by less than 1 Ahr.
6. Contrary to popular belief, the Red's and Yellow's C1 rating differ, on average, by LESS THAN 1Ahr. See chart above. (Have I stressed this enough?)
Popular thinking was that because the batteries had a C20 rating difference of 4 Ahrs (see specs here), it was assumed that electrathon racers would be able to go either much further, or much faster in the given hour. This would be a huge safety concern to me as a teacher, as my top priority is safety for my students. This was proven not to be true as shown by the data.
Since we use the batteries in one hour, you cannot apply the C20 rating.
We have tested old, not so old, and brand new batteries, and have come to the above conclusions. Please see the posts previous to this for the Testing Procedure we used, as well as the test set up.
This data does not take into account any different driving "styles", just the cold hard facts about the two batteries: Optima Red & Yellow Tops.
In closing: because the Yellow tops will have a much greater life span than the Red Tops, and do NOT give a significant difference in Ahr rating for one hour, I strongly recommend moving to the Yellows for cost savings and recycleability alone. They may cost a bit more but will last 5x's (at least; I'm being conservative, as we have not tested this) as many charge/discharge cycles.
I tried to post the data from some year long testing we have done on this topic, and it wasn't allowed.
Al our test data, conclusions, procedures, graphs & curves, ect can be found at the link below. To answer the questions posted above:
Is there an 8% increase in the yellows? NO
Are the Yellows rated at 42+Ahrs, and reds 35 Ahrs for one hour (C1 rating)? NO
Do the Yellows give you alot more life? YES
Long Story Short:
"...because the Yellow tops will have a much greater life span than the Red Tops, and do NOT give a significant difference in Ahr rating for one hour, I strongly recommend moving to the Yellows for cost savings and recycleability alone. They may cost a bit more but will last 5x's (at least; I'm being very conservative, as we have not tested this) as many charge/discharge cycles."
Full details and Test results at: http://www.nyelectrathon.com/index.php?option=com_ccboard&view=postlist&forum=14&topic=30&Itemid=99
-- Edited by churd on Friday 21st of January 2011 06:00:08 PM
Zaine Stapleton said
Jan 21, 2011
Churd,
I did check out the nyelectrathon.com website and I think you have a point about switching to yellow tops. At the last couple of races here in the Northwest for the summer/fall events, I was getting the same output everyday with close to the same watt hour rating (I use watts instead of amps) after the hour was up. At both events, I placed very well using my set of yellow tops (da Vinci days 2nd, Eugene Celebration Kilowatt Klassic first beating everyone in student and adult.) Yes, yellow tops are slightly different compared to reds, but if you want to save money in the long run and have a set of batteries that will last for three to five years putting close to the same output then buying a set EVERY YEAR I say it's worth it.
-- Edited by Zaine Stapleton on Friday 21st of January 2011 06:33:30 PM
mhodgertt said
Jan 22, 2011
That is why I pushed the yellow tops through. I used to have to buy about 40 red top batteries EVERY YEAR for our 20 cars. I could not afford to keep replacing them after 12 to 18 races depending on care and abuse.
bd64 said
Jan 22, 2011
"because the Yellow tops will have a much greater life span than the Red Tops" --- I would not bet on it. Continued cycling can be used as an indicator but only that. If they follow the 22NF lead they will sulfate with time and become worthless.
churd said
Jan 22, 2011
bd64 wrote:
"because the Yellow tops will have a much greater life span than the Red Tops" --- I would not bet on it. Continued cycling can be used as an indicator but only that. If they follow the 22NF lead they will sulfate with time and become worthless.
I do not believe this is true; although all bateries will sulfate over time, because of the chemistry, it has been proven by industry that most deep cycle batteries have a much longer charge/discharge cycle life than their starter counterparts. Engineers at Optima have also stood behind me and even used a much a higher life expectancy than I had previously stated.
churd said
Jan 22, 2011
mhodgertt wrote:
That is why I pushed the yellow tops through. I used to have to buy about 40 red top batteries EVERY YEAR for our 20 cars. I could not afford to keep replacing them after 12 to 18 races depending on care and abuse.
I couldn't agree more, I am just glad that after the testing was done, it proved that there was not an 8-15% increase in Ahr rating. This way we keep the safety factor, save money, and it is better for the environment!
Zaine Stapleton said
Jan 22, 2011
I'm glad I got yellow tops last year, now knowing that they will last a lot longer compared to the red tops. I think it's good to have change by switching to a different battery. And I don't see the yellow tops being dangerous for causing high speed crashes.
The crashes that did happen here in the Northwest were issues that could have been better thought out when building a car, like having a reliable steering system. There were cars that snapped axles, but could be said as just something that happens in racing. The snapped axles were not that serious, just kind of got everyone's attention when a car went sliding into a curb or tire wall. Not all things can be prevented.
bd64 said
Jan 22, 2011
I sure hope Chris is right and I am wrong about how long the yellows last but the number of cycles does not tell the whole story. Batteries need to last through period of inactivity and even some neglect to truely save money on batteries. The Red tops can and should be repurposed rather than recycled, the old SLIs and currently Red tops are still starting cars, trucks, tractors and other gas powered equipment before they are returned for core charges. What will you use the Yellow tops for?? The sales people missed on the 8% increase in output will their prediction on longivity be any better? Time will tell.
mhodgertt said
Jan 22, 2011
You are right that the Optimas (and even the old flooded acid ones we used to use) can have great long life after they are no longer 100% for Electrathons or other electric cars. My students bought many of the red tops for ~$20 dollars after they were 'race batteries' for a full season and then 'practice/warm up batteries' for a year or two. Some of these they are still using that they bought several years ago and are still working great. The yellow tops also work as starting batteries according to Optima (as apposed to the blue tops that are true deep cycles) so I hope to be able to sell these to students in SEVERAL years for the same purpose.
mhodgertt said
Jan 22, 2011
I will admit that I would be very surprised if the batteries last 4 to 6 years of racing as the number of cycles would indicate. But if they even just last 2 seasons instead of one they are half price!!!!!! and half as many batteries to find homes for. I am fairly confident that they will last 2 seasons and I am hoping they still will well work for a full three years of races which for us would be about 45 to 55 cycles or races.
Zaine Stapleton said
Jan 23, 2011
Mike, one of the sets of practice batteries I bought from you last year at the LCC race I was using one of them in my 1959 Volkswagen Beetle. It turns the motor over as long as I drive it everyday or every couple days. Otherwise the battery will drain off and won't do anything. But I'm still able to recharge it and get the voltage back up to 13.2 volts with no problems.
-- Edited by Zaine Stapleton on Sunday 23rd of January 2011 12:47:14 AM
bgilmore said
Jan 23, 2011
+1 with what Chris said about the safety factor. These yellows are pulling the same numbers as reds, no increase in speeds, plus according to an applications engineer at Optima "in our lab testing, if you discharge 100% you'll get approx. 300 cycles, if you discharge 50% you'll get about 1000 cycles." This information is for the yellows.
Zaine Stapleton said
Jan 23, 2011
did Optima say what the information was if you applied the same thing to a red top? I would be interested on how many cycles it could do before you had to replace them.
bgilmore said
Jan 23, 2011
ha, only to not do it.
no data though.
-- Edited by bgilmore on Sunday 23rd of January 2011 06:04:12 PM
mhodgertt said
Jan 24, 2011
Zaine,
Are you sure you don't have a voltage drain in your bug. Next time it is going to sit for a few days disconnect one of the battery cables and see if it will hold a charge then.
Mike
Zaine Stapleton said
Jan 24, 2011
Mike, I am considering putting in a Harbor Freight battery disconnect near the battery out of the way so that won't happen. I'll probably use the same type of kill switch I'm using in my electrathon car, usually $5. I just haven't had time to do it since I'm only at home for a couple days.
-- Edited by Zaine Stapleton on Monday 24th of January 2011 04:45:21 AM
bd64 said
Jan 25, 2011
The board has gone stale again. Someone say something about batteries or something.
stan r said
Jan 26, 2011
my battery requires a frequent recharge & doesn't last nearly as long as it used to, maybe that's because I'm 72, (I'm only good for about 4 miles a day).
Zaine Stapleton said
May 3, 2011
Here's something to talk about. Mike, is it true that car #99 from your school has been using yellow tops the entire season? If so, then the yellow tops are doing their thing and are working better compared to the red tops looking at the season results. I looked at the LCC race from last year and compared my results to this years results since I was using red tops last year up to the summer races. Andrew (#99) got two more laps than I did last year (49 for me, 51 for Andrew.)
Plus I counted 20 of the 25 cars in the top 25 that are using yellow tops. So yellow tops are working very well if you look at if from that point of view.
mhodgertt said
May 5, 2011
Zaine and all, As I have said... for the last half of last year (after I learned to drive them a little differently to get more power out)... and all of this year I am going as far or a little farther than I was able to the year before on my red tops.
Mark Bray from Thurston High who is using yellow tops this year tells his kids that yellow tops are like a magic cupcakes. 'If you lick off the frosting more will magically appear unless you bite the cake, then no more frosting will appear.' For me I have started using my volt meter more and watch to make sure I don't go below 21.5 volts for as long as possible. At about 30-40 minutes into the race the batteries get to about this point so I make a real effort not to use any more amps than I need to for a lap or two. So I slow down a little and don't accelerate as much at all if any coming out of a corner or up hills. I don't lose too much 'distance' for these two laps. After this 'rest' I can hit it hard again as the voltage under power is now about 23.5-24 volts again. I watch my volt gauge closely for the rest of the race and if needed, I slow down for one more lap if my voltage drops too much. Doing this I have hardly slowed down at all in any race this season (except one I did not do the second 'rest' lap) and am going farther than I used to by a lap or two at each race.
Since these are deep cycle it is harder to get the power out and that is why I think they need a rest period to be able to pull out more power as opposed to the starter batteries that have their power closer to the surface.
I'm seeing a lot of conflicting information on which batteries should work best. I am going to buy two new sets this year and am leaning towards the yellows (recommended by Optima for both performance and longevity), but have seen some conflicting information and don't want to 'waste' 800 bucks.
What are you doing this year?
I think the energy is in there, just not able to get it all out in an hour.
Shannon, if Dave has data it would be great if you would post it.
One of the other high school teams, also and Auto Tech Program, has used Yellow tops since last Dec.
I have not been impressed with their performance. Their car is a clone of ours, we helped them get started, and they have had two DNFs because of batteries and one Black Flag due to batteries. One race they had a bad battery at the start and had to swith out before they could even get off of the start line.
We have yet to have a bad result due to batteries or electrical problems. We are using Red Tops and Kelly controlers. We ran through a bunch of thumb throttles before swithching to twist grips.
well i have school, but my dad wants to go, he has thoughts of a new car.
http://www.nyelectrathon.com/index.php?option=com_ccboard&view=topiclist&forum=14&Itemid=99
-- Edited by bd64 on Wednesday 16th of June 2010 12:10:20 PM
Good job Nathan, you deserved the win! :D
What does this data mean? Could you please elaborate?
Optima says 44 for red, 48 for yellows at C20.
Data sheet HERE
-- Edited by churd on Saturday 18th of September 2010 01:56:19 AM
Below is a post I made after doing some testing on yellovs red tops. The full discussion, including full downloads of all data and testing procedures can be found here:
http://www.nyelectrathon.com/index.php?option=com_ccboard&view=postlist&forum=14&topic=30&Itemid=99
From carefully analyzing the data in the previous post (and summarized above) we have drawn the following conclusions:
1. All batteries are NOT created equal. From the factory, the batteries can have a C1 rating that can vary by up to 3-4 Ahrs from battery to battery. Choose wisely; if you have a choice.
2. Both Reds & Yellows are green directly from the factory; They do NOT hold an optimal charge, and get better over time. (see data in the previous post)
3. Both Reds & Yellows improve with age; to a point. What is that point? We don't know, as we haven't reached it yet. It could be as many as 10 to 15 charge/discharge cycles for the yellow tops. (Thanks Dave!)
4. How you charge the batteries does have an effect on the final Ahr rating, but when charged similarly, the yellows and the reds overall differ by less than 1Ahr at a C1 rating.
5. The discharge curves for the two diferent batteries have almost exactly the same profiles. See the attached files as well as the graph below.
In the chart above, the red & green lines represent the factory yellow tops, and the black & blue the factory red tops. As you can see the curves are exactly the same with the C1 Ahr rating averages differ by less than 1 Ahr.
6. Contrary to popular belief, the Red's and Yellow's C1 rating differ, on average, by LESS THAN 1Ahr. See chart above. (Have I stressed this enough?)
Popular thinking was that because the batteries had a C20 rating difference of 4 Ahrs (see specs here), it was assumed that electrathon racers would be able to go either much further, or much faster in the given hour. This would be a huge safety concern to me as a teacher, as my top priority is safety for my students. This was proven not to be true as shown by the data.
Since we use the batteries in one hour, you cannot apply the C20 rating.
We have tested old, not so old, and brand new batteries, and have come to the above conclusions. Please see the posts previous to this for the Testing Procedure we used, as well as the test set up.
This data does not take into account any different driving "styles", just the cold hard facts about the two batteries: Optima Red & Yellow Tops.
In closing: because the Yellow tops will have a much greater life span than the Red Tops, and do NOT give a significant difference in Ahr rating for one hour, I strongly recommend moving to the Yellows for cost savings and recycleability alone. They may cost a bit more but will last 5x's (at least; I'm being conservative, as we have not tested this) as many charge/discharge cycles.
We would love to hear your comments!
Al our test data, conclusions, procedures, graphs & curves, ect can be found at the link below. To answer the questions posted above:
Is there an 8% increase in the yellows? NO
Are the Yellows rated at 42+Ahrs, and reds 35 Ahrs for one hour (C1 rating)? NO
Do the Yellows give you alot more life? YES
Long Story Short:
"...because the Yellow tops will have a much greater life span than the Red Tops, and do NOT give a significant difference in Ahr rating for one hour, I strongly recommend moving to the Yellows for cost savings and recycleability alone. They may cost a bit more but will last 5x's (at least; I'm being very conservative, as we have not tested this) as many charge/discharge cycles."
Full details and Test results at:
http://www.nyelectrathon.com/index.php?option=com_ccboard&view=postlist&forum=14&topic=30&Itemid=99
-- Edited by churd on Friday 21st of January 2011 06:00:08 PM
-- Edited by Zaine Stapleton on Friday 21st of January 2011 06:33:30 PM
-- Edited by Zaine Stapleton on Sunday 23rd of January 2011 12:47:14 AM
no data though.
-- Edited by bgilmore on Sunday 23rd of January 2011 06:04:12 PM
-- Edited by Zaine Stapleton on Monday 24th of January 2011 04:45:21 AM
Here's something to talk about. Mike, is it true that car #99 from your school has been using yellow tops the entire season? If so, then the yellow tops are doing their thing and are working better compared to the red tops looking at the season results. I looked at the LCC race from last year and compared my results to this years results since I was using red tops last year up to the summer races. Andrew (#99) got two more laps than I did last year (49 for me, 51 for Andrew.)
Plus I counted 20 of the 25 cars in the top 25 that are using yellow tops. So yellow tops are working very well if you look at if from that point of view.
As I have said... for the last half of last year (after I learned to drive them a little differently to get more power out)... and all of this year I am going as far or a little farther than I was able to the year before on my red tops.
Mark Bray from Thurston High who is using yellow tops this year tells his kids that yellow tops are like a magic cupcakes. 'If you lick off the frosting more will magically appear unless you bite the cake, then no more frosting will appear.' For me I have started using my volt meter more and watch to make sure I don't go below 21.5 volts for as long as possible. At about 30-40 minutes into the race the batteries get to about this point so I make a real effort not to use any more amps than I need to for a lap or two. So I slow down a little and don't accelerate as much at all if any coming out of a corner or up hills. I don't lose too much 'distance' for these two laps. After this 'rest' I can hit it hard again as the voltage under power is now about 23.5-24 volts again. I watch my volt gauge closely for the rest of the race and if needed, I slow down for one more lap if my voltage drops too much. Doing this I have hardly slowed down at all in any race this season (except one I did not do the second 'rest' lap) and am going farther than I used to by a lap or two at each race.
Since these are deep cycle it is harder to get the power out and that is why I think they need a rest period to be able to pull out more power as opposed to the starter batteries that have their power closer to the surface.
Mike