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Team: Shock Therapy. Members: Tim Blake, Travis McMillen , David Bankhead. Advisors. Jim Klein – NAVY sponsor/contact Dr. Herb Hess – Faculty Advisor. Background. Why is this project important to the NAVY? Goal of Bayview : Create quieter NAVY vehicles
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Team: Shock Therapy Members: Tim Blake, Travis McMillen, David Bankhead
Advisors • Jim Klein – NAVY sponsor/contact • Dr. Herb Hess – Faculty Advisor
Background • Why is this project important to the NAVY? • Goal of Bayview: Create quieter NAVY vehicles • Done by using batteries to run their vehicle • One ship uses hundreds of batteries • Example: LSV-2 Cutthroat • Batteries need to be replaced every 4 years • NAVY wants to improve battery performance
Project Definition • NAVY • Compare pulse charging and CCCV (Constant Current Constant Voltage) • Determine if indicators exist that a battery can/can’t be rejuvenated • University of Idaho • Essentially – Design the Design project! • End Goal of the NAVY • Extend the life of their batteries • Find the most viable charging solution
Constant Current Constant Voltage • Two step charging system • Battery is initially charged with a constant current until the terminal voltage reaches a threshold (between 13.5 & 14.7 V) • Constant voltage is then applied until current tails off to a trickle limit • Indicates charge is finished • Advantages: • Easily understood • Widely implemented • Problems • Inefficient • Slow • Battery degrades with many cycles
Pulse charging • Applies relatively large currents at periodic intervals with defined pulse width • Advantages: • Avoids gassing the battery • Increases charge acceptance and efficiency • Can be used to provide a float charge • Provides significant reductions in charging time and an increase of cycle life. • Recovers the capacity of exhausted or cycled cells • Disadvantages • Results not proven (just claims) • We hope to prove the claims of pulse charging
Comparing Pulse and CCCV Figure 1: Relative Charging Rates
Project Needs • Batteries – Given • Rejuvenators – Given
What we’ve done so far • Preliminary setup • Developed test setup for discharging • Developed recharging method using CCCV or pulse charging • Find a way to measure impedance of the battery (To be done in the future)
What we’ve done so far • 1st discharge test (USED & Previously rejuvenated)
What we’ve done so far • 2nd discharge test (UNUSED SPARE)
What we’ve done so far • 1st Rejuvenation test (UNUSED SPARE)
Battery discharging • Need to measure • Starting voltage • Ending voltage after discharge • Will have a normal and a deep discharge • Voltage of Battery after sitting • Battery temperature • Current • Internal Resistance
Discharge setup Figure 2: Battery discharge setup (for 12 V and 2 V)
Battery Rejuvenation • Measure: • Starting voltage • Ending voltage • Immediately after & 24 hours later • Temperature during process • Current behavior • Internal Resistance
Rejuvenator Setup Figure 4: Battery Charging Setup (for 2 V) Figure 3: Battery Charging setup (for 12 V)
Characteristics of a good rejuvenator • Decreases time it takes to charge • Increases battery life • Decreases internal resistance • Increases battery capacity
Measuring the internal resistance + VT - Figure 4: Diagram to measure internal resistance
What does all this have to do with the project? • Data obtained from tests will allow us to observe behavior of batteries and how the rejuvenators interact with them. • Using this, we identify rejuvenator characteristics that lead to desired specs identifying a good rejuvenator. • Procedure would allow NAVY to continue their research to characterize pulse rejuvenator and would allow them to find the best rejuvenator for whatever task is at hand for them.
Forming the procedure from data • Data would then be used to form a null hypothesis • Ex: Charger B is better than Charger A for Task X • Procedure would be based off of verification or falsification of the null hypothesis
Deliverables • Detailed process or algorithm the NAVY can follow to charge/rejuvenate their batteries
Viable Designs • Procedure for testing battery rejuvenators • Software algorithm that will output characteristics of battery rejuvenator
Procedure for testing battery rejuvenators • Would be able to identify rejuvenator compatibility with batteries • How to accomplish this: • Develop a specific test setup • People utilize a procedure determined by our analysis of batteries/rejuvenators • Procedure would result from statistical analysis of our data • Results in determination of compatibility of rejuvenator with batteries
Develop a procedure for testing the rejuvenators • Pros • NAVY can continue research • Can determine best type of rejuvenator • Cons • Could be labor intensive • May not have enough chargers to get conclusive results • Not a “set it and forget it” procedure
Software algorithm • Would involve creating a program monitoring the interaction of rejuvenators and batteries • Also would automate rejuvenator testing process • Outputs data necessary to make decision with little manpower involved • Based on the procedure for testing the rejuvenators • Plan to accomplish this through LABVIEW
Software algorithm • Pros • Completely automated since run by microprocessor • Could be faster than other options in obtaining results • Cons • Compatibility issues • With certain kinds of batteries • May be more expensive • Could be time intensive
Possible difficulties • Charging 2 V with 12 V battery rejuvenator • Possibly test both ways to see if it makes a difference • Will 3 rejuvenators of different types give concrete results? • Testing time • Inconclusive results • Have many resources at our disposal to help interpret
TIMELINE 7 Months 2010 Nov Dec May Feb Jan April March Testing Formulate data from testing into procedure Order/acquire Parts Verify procedure works Finalize project