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Post Info TOPIC: Batteries
bd64


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Batteries
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Do Not go and recycle your Red Top batteries if you voted NO to the rule change.  If you voted YES then by all means buy two pair or more for each vehicle you own. Here is part of a post I made on the Nebraska discussion board. http://nebraskapowerdrive.proboards.com/index.cgi

 

In the past, I have had first hand experience with flooded cell deep cycle, flooded cell SLI, and the current SLI AGM batteries and it is from these experiences I have learned

 

  1. Most batteries become unsuitable for competition due to improper charging methods and poor off-season periodic maintenance. The number of cycles or the number of possible cycles is not a large factor in the life of a battery.
  2. Deep cycle batteries do not have the same power or energy density as SLI batteries.
  3. C-10, C-20, CCA, or CA ratings on batteries have little meaning for this type of use.  The RC does seem to have a correlation to our use.  The RC multiplied by 0.4 will give you a good approximation of the one-hour current draw limitations.
  4. Amp Hr is a deceptive tool to use to predict the amount of work you can get from a battery a much better tool would be Watt-Min or KW-Hr.

 

Look for an AGM SLI that meets the 73lb battery pack requirements, apparently it has already been found and this is a quote from the NE board

 

We have experimented with batteries that are slightly overweight and can get our junker car up to 53 miles an hour for an hour.  Brent Essink

 

 

So, here are my conclusions Yellow Top batteries cost more than Red Top batteries.  Both Yellow Top and Red Top batteries will have about the same life expectancy and about the same KW-Hr output. 

 
Thank youRuss



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electrathon


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I moved this from the rule change section to the battery section.

The votes have been turned in, we well be going faster / more agressively next year. At this point I think there will be a lot of discussion about if it will be from having deep cycle batteries or becouse we no can use larger starting batteries. Please post your thoughts on this. If you have ran tests, please contribute.

The way I understand it: Deep cycle batteries would be the perfect match for us if we ran 3 hour races. With one hour races they tend to "hold back" the amperage to release later. Sort of like dumping water out of a bucket. A starting battery is a 5 gallon bucket full of water, a deep cycle is a 6 gallon bucket full of spunges, full of water. Turn them both on their side and which one will spill out the most water.

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bd64


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Supercharge Your Batteries

 

The J-Hudson Charging Method

 

by Jay Henderson

Raymond Central PowerDrive Instructor

 

 

This process came about because so many batteries tested were too low to be used in Power Drive Endurance Competition.

 

Some new batteries are not charged up evenly; the cells are not all equal.  This process could be called cell equalization.  Charging even good batteries this way may improve their performance as well.  Repeating this process weekly may not further improve the amp rating.  It is not necessary until the batteries have gone unused for awhile.

 

Equipment needed:

 

  1. A 20 gallon (approximate) container at least 7 10 deep.  This container will need a method of heating the water to approximately 135 degrees.  A water heater element and a control to set the temperature seems to work well.

 

  1. A battery charger with a manual and an automatic setting.

 

  1. A multimeter to check volts and amperage (3 would be handy to have).

 

  1. An infrared thermometer is very quick to check water and battery temperatures.

 

  1. Two 10 to 12 guage jumper wires with clips on the ends about 18 20 long.

 

  1. Extension cord with a house light dimmer on one wire.

 

Procedure:

 

1.      Batteries must be fully charged on the automatic setting.  Set the batteries in the container on top of something to keep them slightly above the bottom of the container.  The water needs to surround them.  Now add cold tap water approximately 55-65 degrees.  The water level needs to stay about three fourths to one half of an inch below the top of the batteries.

 

2.      Connect one battery charger to two (2) batteries.  Set the charger on the manual setting.   Put a small amount of soapy water on the two battery vents to detect gassing.

 

Optional extension cord usage:

      Plug the extension cord into the AC outlet, then plug the charger into the extension cord.  This can be used to limit voltage and amperes thereby further controlling this process.

 

3.      Plug in charger and watch the vents for bubbles.  Check the battery voltage often when one of the batteries starts gassing, stop the charging process.  Voltage will be approximately 16.10 plus or minus.

 

4.      Turn on the heating element and warm up the batteries until they reach 118 degrees.  No more than 120 degrees.  Check battery temperature getting a reading from the lead posts.  The posts are hollow.  Best temps are taken right on top of the post.

 

When batteries are up to temperature 118-120 degrees remove the water and test for optimum amperage output.


I have data sheets showing battery output " Red Top" before and after using this charging method.  They are in a table format and I do not know how well they will paste into this format.

russ

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bd64


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Battery Test Data

 

 

Battery B1   Manufactures release date March 2005

                    Delivery date February 2006

 

Data collection June 2,2008

 

Battery Temperature 70F   Open circuit voltage 12.84V

Battery charged on automatic 10Amp charger

 

Time

Voltage

Current

Power

0 +

12.05

38

---

3

12.00

38

456

6

11.84

38

450

9

11.82

38

449

12

11.80

38

448

15

11.77

38

447

18

11.72

38

445

21

11.68

38

443

24

11.63

38

442

27

11.57

38

440

30

11.51

38

437

33

11.45

38

432

36

11.37

38

429

39

11.29

38

426

42

11.20

38

422

45

11.10

38

417

48

10.98

38

412

51

10.83

38

404

54

10.62

38

403

55

10.5

38

---

 

Total Work through the cycle 23885 Watt-Minutes or 0.398 KW HR

Average voltage 11.8V as per manufactures half duty cycle

 

Average Amp-Hr output 33.7 amps

 

Even though this battery spent excessive time on the charger it end up being under charged.

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bd64


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Battery B1 using the J-Hudson charging method

 

Data collection July 2009

 

Battery temperature 118F Open circuit voltage 12.96V

 

Time

Voltage

Current

Power

0+

12.28

40

----

3

12.33

40

493

6

12.29

40

492

9

12.24

40

490

12

12.19

40

488

15

12.13

40

485

18

12.08

40

483

21

12.01

40

480

24

11.95

40

478

27

11.88

40

475

30

11.81

40

472

33

11.73

40

469

36

11.66

40

466

39

11.57

40

463

42

11.48

40

459

45

11.38

40

455

48

11.26

40

450

51

11.12

40

445

54

10.94

40

438

57

10.66

40

426

58

10.5

40

----

 

 

Total Work through the cycle 27250 Watt-Minutes or 0.454 KW-HR

Average calculated voltage 11.77V half duty cycle

 

Average Amp Hr output 38.5 amps using 11.8V average voltage

 

This battery appears to be full charged and suitable for use in competition.

 

All tests were performed with + or   0.1 amp precision.


The same type of results were achieved independently by Jay Henderson of Ramond Central, Tony Cantral of Wayne, Bill Kalblinger of North Platte, and myself. 



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radigan


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Thanks for the information.  There is so much to learn even after years of doing this.

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Ron Cox
Clearwater High School
1201 East Ross
Clearwater Kansas 67026
http://courses.usd264.org/hs/cox/index.htm
Sam Lee

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In my electric car program we decided to continue to use red top batteries even after the rule change but we trying to find a combination that weighs 72 pounds.

does anyone know a combination of redtops that weighs 72 lbs?



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bd64


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Sam you need to remember that your battery pack is only as good as your weakest cell.  Just increasing weight will be of no benifit, but if you decide to try anyway put your larger battery on the negative side of your electrical system.

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bd64


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Here is some preliminary info, I received some data --well alot of data from Barry Wilson of CR Kennedy that his students collected using real time telemetry from a car setting on a dyno.  Five spread sheets of 1200 rows and five columns of data.

Here are my preliminary findings

Average voltage over 48 min 22.74 volts but over a 60 min period it would be 18.19 volts.

 

Total work done by yellow tops 44,754 watt minutes or .746 killowatt hours for the battery pack or .372 kilowatt hours per battery.  This is extremely poor!!! Our red tops not fit to use in competition yielded .398 kilowatt hours before the J-Hudson treatment and .454 kilowatt hours after.  That is per battery and  .796 KW Hr per pack before and .908 KW Hr after the treatment.

 

I am sure glad all of those that voted yes will be buying new batteries ---

I will post more info when I get to run my own tests so I know that I am comparing apples to apples.

russ

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stan r


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electric motor speed is governed by voltage, not amperage, therefore if your car is using red tops (24) volts it will go the same speed with yellow tops (24) volts. With the yellow tops, if it goes faster the reason is that you now have more power, (amps), available & can now attain full rpm. Previously with the red tops you were not reaching maximum rpm so you went slower. Your car wasn't geared properly. Possibly excess weight or aerodynamics was playing a part in your top speed.

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stan r
Anonymous

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How long did the batteries sit after they were in the 118 degree bath?  In other words, was the J-Hudson battery pack allowed to cool to room temp before being tested?

Were both batteries (the regularly charged battery and the J-Hudson charged battery) tested at the same ambient temperature?

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bd64


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The battery temp is on the top of each page, you need to keep the batteries warm or hot until use in competition. Heat alone without the J-Hudson treatment will increase output about 3/4 amp per battery pack.

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Anonymous

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If the J-Hudson batteries were warmer than the other batteries, then the results don't mean a thing.  To make this fair, warm up the regularily charged batteries up to the same temp and see if there is still an advantage to the J-hudson method.

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bd64


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Do as you wish.

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Anonymous

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What other methods do people use to heat the batteries?  How long does it take to heat them and does the 118 degrees apply to methods other than the J-Hudson method?

Thanks...



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stan r


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we used a plastic insulated cooler large enough for 4 batteries. Make a hole in the side large enough for the end of an electric hair dryer whose temperature will be controlled by a thermostat from a hot water heater. Separate the batteries with 1" wood strips sp air can circulate between them. You can leave the dryer on 24 hr. because of the thermostat

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stan r
monkeywithawrench


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ok i am confused about the weight of the batteries that is allowed. in the rule book, it says both 67lbs is the max limit and it says 72lbs is the max limit. can someone please help before i go battery shopping. thanks

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electrathon


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For the 2010 season the weight was raised to 73 pounds. Last season it was 67 pounds.

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monkeywithawrench


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thanks. someone might want to correct the rules hand book, as it says both 67 and 73 lbs in the weight limit.

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electrathon


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Are you reading online of a hard copy? What pages are you seeing the 67 lb part?

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monkeywithawrench


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http://electrathonamerica.org/Rule_Book_&_Forms_files/HANDBOOK%202010-11%20smaller.pdf page 32 and halfway down page 25

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electrathon


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Thanks, I passed the word on. It should be fixed soon.

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