MOLECULAR REBAR™ INCREASES LIFE OF BATTERIES IN DEEP CYCLE APPLICATIONS Dr. Nanjan Sugumaran Mr. Steven Swogger Dr. Paul Everill 11 Battery Consultant Black Diamond Structures, USA Black Diamond Structures, USA Factors that impact the Life/Ah Throughput of a Battery Battery Design Charger Quality Battery Life Battery / Ah Throughput Charging Algorithm 2 Duty Cycle General Failure Modes: With a Good Charger & Charging Algorithm Active Material Shedding (Battery) Acid Stratification (Charger) Water-loss (Charger & Battery) Active Material Loosening (Charger) 3 Sulphate Growth (Battery) Hydration Short (Battery) Positive Plate Corrosion (Charger) General Failure Modes: Over-Charging Active Material Shedding (Battery) Acid Stratification (Charger) Water-loss (Charger & Battery) Active Material Loosening (Charger) 4 Sulphate Growth (Battery) Hydration Short (Battery) Positive Plate Corrosion (Charger) Charger Induced Failure: Over-Charging 1) Control based on battery charging voltage 2) Ah input is 130% of previous discharge 3) CC1- CC2 charger and battery do not have any role in Ah acceptance 4) Water loss and corrosion are the major issues 5) Moderate life for battery 5 Charger Induced Failure: Under-charging 1) Control based on Battery EMF 2) Ah input is <100% of previous output 3) Variable current and battery do not have any role in Ah acceptance 4) Stratification and sulphation are the major issues 5) Very low life for battery 7 MOLECULAR REBAR™ (Pb2100N) in Deep Cycle Batteries Trial Programs E-Rickshaw + Solar - 0.16% wrto Tubular Plate Pb2100N 9 + - 0.16% wrto Tubular Plate Pb2100N Solar Battery Trial Program • • • • 10 Positive Plate: Tubular Negative Plate: 0.16% wrto / 56L of Pb2100N Compared vs. Control without Pb2100N 150Ah Rated Capacity 10 Solar Batteries: Capacity at Various Discharge Rates Control Pb2100N 11 11 Solar Batteries: TOC Voltage at C/10 Charging Rate Pb2100N lowers TOC Voltage by 300 mV at C/10 rate 12 Control Pb2100N 12 Solar Battery: 60% DOD Cycle Throughput Hours to Charge 100Ah @ 15V/15A from 60% DOD Control Pb2100N Av. CON = 14.84 h Av. MR = 9.66 h 13 Inverter (Tubular Plate) Recharge times decreased 35%+ 20-30% decreased water loss on cycling Solar Batteries: Various Life Cycle Tests & Failures IEC 61427 NF 58510 PPER QUALIBAT 10% SOC 40% SOC DRE Stratification/ Hydration Short L H L L H H M Sulfation M M M M H M M Corrosion/Water loss/ Active Material Loosening M Active Material Shedding L L M H L H L L M DRE (Decentralized Rural Electrification) test selected to exercise all key failure modes 14 14 Solar Batteries: DRE - Life Cycle Test Procedure Step Mode 1 Preparation Protocol Cycles 1) Fully charge the battery 2) Discharge at C/10 A till 10.5V 1) Charge at C/10A till 14.1V 2 Undercharge cycles Potential Failure 2) Rest for 3 hrs 3) Discharge at C/10A till 10.5V Acid stratification 5 Sulphate growth 4) Rest for 3 hrs AM shedding 1) Charge at C/10A till 120% Capacity Corrosion Active Material loosening 3 Overcharge cycles 2) Rest for 3 hrs 5 Sulphate growth 3) Discharge at C/10A till 10.5V Active Material shedding 4) Rest for 3 hrs Waterloss Repeat sequences 2 and 3 until discharge capacity in overcharge cycle drops below 70% of C/10 capacity 15 15 Solar Batteries: DRE Capacity Evolution Control Pb2100N 16 16 Solar Batteries: DRE Cycling Control Pb2100N Fate of Excess Ah 20.50 Blue = Theoretical Red = Actual 20.00 Ltrs 19.50 19.00 20.15 18.50 18.00 18.46 18.85 18.57 17.50 dCNT Pb2100N 17 Control Pb2100N 1) sp.gr in Pb2100N is higher than in Control 2) In Control, increased sp.gr after 300 cycles by 20pts indicates excess Ah goes to water splitting as per Faradays law 3) In case of Pb2100N, 21% of excess Ah is getting converted in to H atom which prevents PbSO4 formation and sulphation formation Control Control 17 Solar Batteries: Value Creation of Pb2100N Battery Manufacturers Reduction in Warranty Cost and/or Increased Warranty 18 Solar Provider / Distributor Reduction in CapEx End-Consumer Increased Battery Life e-Rickshaw Trial Program • • • • 19 Positive Plate: Tubular Negative Plate: 0.16% wrto / 56L of Pb2100N Compared vs. Control without Pb2100N 80Ah Rated Capacity 19 e-Rickshaw Battery: Recharge Factor 14.8V/20-hour charging step (16A limit) Pb2100N increases charge factor by 5% over Control 20 20 e-Rickshaw Battery: Life cycle test procedure Step Mode 1 Preparation 2 Discharge 3 Charge Protocol Cycles Potential Failure 1) Fully charge the battery 1) Discharge at 0.15 C for 1 hr 2) Rest for 1 hr Charge at 14.8 V/0.15C for 6 hrs 5 Sulphate growth Acid stratification Repeat sequences 2 and 3 until discharge capacity sustains 3 cycles in step 2. 21 e-Rickshaw Battery: Life Cycle Simulation • e-Rickshaw Daily Duty Cycle Simulation • Pb2100N Charges @ 14.8V & Maintains Capacity & End-of-Discharge Voltage 22 e-Rickshaw Battery: Life Cycle Simulation Result Analysis Unit # 9 Charging Voltage No. of Cycles Remarks Control Pb2100N Control Pb2100N 14.8 14.8 5 5 Control failed in 9th unit 10-140 15.2 14.8 5 5 Control nor Pb2100N provided 5 cycles after 140 units due to very cold weather; night temp < 10 C 141-157 15.2 14.8 5 5 Continued 157-220 15.2 14.8 4 4 Cycle #s reduced to 4. Control failed. Water topped. 220-242 15.2 15.2 4 4 Charging Voltage for Pb2100N changed to 15.2V Total Water consumption till 242 cycles Control 1545 ml Pb2100N 930 ml 1) So far 13,500Ah has taken out from battery which is equivalent to running E-rickshaw for 225 days 2) Pb2100N battery is much more healthier than Control; in the field it would have give more Ah output in given days 23 e-Rickshaw Battery: Field Trial Results • Scope • 3 e-Rickshaw drivers w/ 4ct 80Ah Pb2100N Tubular batteries • Water consumption, OCV, average charging times and other parameters monitored bi-weekly • Voltage meters installed; monitored weekly • Major Observations by Drivers & Owners using Pb2100N • Pb2100N batteries DO NOT NEED A DAYTIME RECHARGE; Standard/Control batteries needed a 2-3 hour recharge • Water consumptions dramatically reduced • Drivers’ daily earnings increased ~100 Rs/day • Due to full 80km use without a 2-3hr recharge 24 e-Rickshaw Field Trial Results: Voltage log data • Standard batteries go ~5.25 hrs before charging • Pb2100N batteries go ~11.0 hrs before charging Pb2100N • Field chargers used (see above images) Shaded Area Shows Charge Periods Pb2100N batteries allow a full day of use before needing to recharge 25 Impact of Pb2100N on Energy Cost with Proper Charger IRs Energy Cost of Charging/Battery/Annum (12V/80Ah 75% DOD) 800 700 600 500 400 300 200 100 0 Pb2100N Existing 0 5 10 15 20 25 30 35 % Overcharge • With 5% overcharge, Pb2100N can sustain capacity maintenance while existing batteries need minimum 15% overcharge; 10% overcharge energy cost can be saved. • Rs. 200 - 600 can be saved per annum per battery in charging energy cost alone (Unit cost electricity Rs. 6.50/- Total days per annum = 300) • For 200,000 E-rickshaw in Delhi alone, with Pb2100N the total savings in terms of power consumption is 48,000,000 units /Annum. This is major savings for the country. • The above units is equivalent to total energy consumption of 47,524 persons in India in a year (1,010 units/person/annum) 26 e-Rickshaw Batteries: Value Creation of Pb2100N Battery Manufacturers Reduction in Warranty Cost and Increased Price Capture Distributor 27 e-Rickshaw Owner/Agent Cost Savings ₨400 per year e-Rickshaw Driver ₨50+ per day Revenue and Increased Battery Life Conclusions Problem Deep Cycle Batteries have two main failure modes: Sulphation and Active Material Shedding Solution Altering Battery chemistry by adding MOLECULAR REBAR™ delays both the Sulphation and Active Material Shedding phenomena MOLECULAR REBAR™ (Pb2100N) for Flooded Deep Cycle Batteries: 1. Increases life in Solar Applications by 35% to 50% 2. Increases throughput in e-Rickshaw Applications bu 35% to 50% 3. Reduces warranty costs by >30% for a given time period 4. Reduces overall wasted Energy 28 Thanks to Our Friends and Partners: ® 29 Thank You for Your Attention Please see Black Diamond Structures at their Booth for additional questions, suggestions, or product inquiries. nanjans@hotmail.com swswogger@bd-structures.com peverill@bd-structures.com 30