ECHARGE FOR BATTERIES 100 WATT SOLAR BATTERY CHARGER System Description & Performance Test Results A major challenge for truckers is maintaining adequate charge and overall health of batteries powering the truck s main engine and auxiliary systems. enow has developed a 100 watt Solar Battery Charger that ensures vehicle and auxiliary batteries are always topped off and ready to go. This system is ideal for vehicles that lose battery charge when powered off for extended periods, and for vehicles with liftgates, refrigeration, lighting, monitoring equipment, or other auxiliary system run on batteries. enow has tested the efficiency of the echarge Solar Battery Charger when used for liftgate batteries. enow chose this application to test because liftgate batteries are notorious for a short life, often running out of power during a delivery cycle and stranding the driver without liftgate capabilities. Improved productivity could amount to $1,000 to $3,000 per year based on improved labor productivity, reduced product spoilage and customer satisfaction. As described below, the test data collected over a five-week period show: - Liftgate battery charge measured at midnight with no load or charging maintained a charge of around.8 volts, an indicator of a fully charged, open circuit battery. - During the test period, minimum voltage never dropped below 11.8 volts, and median voltage was.8 volts or greater. - The daily usage profile also shows that minimum voltage never dips below volts and exceeds.8 volts most of the time. - Because the system ensures that batteries are never left in a discharged or partially charged state, battery life should be extended from 1-2 years to 3-4 years depending on battery type. This translates into annual savings of $200 to $800. - Payback period is estimated at 1-2 years based on battery effectiveness, and could be shorter if avoidance of costs for battery maintenance or road service calls is factored in, saving $150 to $600 per call based on geographic location. In addition to trickle charging the batteries, the 100 watt system contributes directly to bulk charging the batteries to replace the battery energy used during liftgate operation. The solar charge system is capable of supplying up to 6 amps of charging energy during most of the daylight hours.
Application Tested Liftgate There are many reasons why liftgate batteries lose charge over the course of a delivery cycle: - There is insufficient run time to fully charge the batteries between deliveries; - The alternator is too small to generate enough excess power to charge liftgate batteries in a short time; - Trailers on which liftgates are mounted are not used for several days or weeks and batteries naturally discharge; - On longer trailers, the distance charge current travels from the engine alternator to the liftgate battery is long enough to result in a voltage drop due to wire resistance and charge current flowing through the wire, which combine to lower the charge voltage below a full charge state; - Trail Chargers mounted in the liftgate battery box to boost the voltage to a level compatible with achieving a full state-of-charge fail due to corrosion or other issues, or are not available. Regardless of the reason, the resulting loss of liftgate function can have an impact on operations and bottom line. Test Design enow worked with a major Northeast distributor to install 75 enow 100 watt Solar Battery Chargers to power liftgate batteries on trailers. Battery voltage data on one of the trailers were collected between April 9th and May 21st of 20 using an Onset HOBO data collector. The trailer on which data were measured used a Trail Charger system running off of the 7 pin trailer connector. The trailer was used in a normal delivery cycle, which included operating in the field for several days, then sitting at the distribution center for several days. Solar energy was collected every day no matter how the trailer was used and stored in the liftgate batteries. For each installation, the solar panel was mounted flat on the top of the truck near the liftgate battery system. A two-conductor cable connected the solar panel to a solar charge controller located in the liftgate battery box. The controller attached to the liftgate batteries through a very short wire harness. The solar charging did not interfere with Trail Chargers or charging directly from the alternator. Performance Data Chart A shows the high, low, and median voltage of the liftgate battery each week for five weeks. The low voltage observed was during a heavy lift and never dropped below 11.8 volts. After the lift, the voltage would rebound back into the volt range. The high voltage was achieved when charging from both the solar charge system and the alternator through the trail charger. The median voltage was the most common battery state. The truck was powered off during all liftgate operations.
Chart A - Liftgate Voltage Range by Week 16 15 11 10 4/20 4/27 5/4 5/11 5/18 Beginning Week Mini Voltage Max Voltage Median Voltage Chart B shows the battery voltage measured at midnight. The battery system voltage was maintained at around.8 volts with no load or charging throughout the monitoring period, an indicator of a fully charged, open circuit battery. Chart B - Battery Voltage at Midnight 16.5.5.5 9 Apr 11 Apr Apr 15 Apr 17 Apr 19 Apr 21 Apr 23 Apr 25 Apr 27 Apr 29 Apr Note: on 4/25 truck was running and charging from alternator 1 May Date 3 May 5 May 7 May 9 May 11 May May 15 May 17 May 19 May 21 May
Chart C shows the battery voltage variation during the workday when the lift would be used at various delivery stops. Minimum voltage never dips below volts and exceeds.8 volts most of the time. Chart C - Liftgate Usage Profile - 4/18/20 15.5.5.5 11.5 11 4:00 4:30 5:00 5:30 6:00 6:30 7:00 7:30 8:00 8:30 9:00 9:30 10:30 11:00 11:30 :00 :30 :00 :30 :00 :30 15:00 15:30 16:00 16:30 17:00 17:30 18:00 18:30 19:00 19:30 Time of Day Chart D shows the profile of the trickle charge over the course of the day. When the sun rises, the solar charge controller first does a brief bulk charge to replenish any energy lost during the night due to normal battery internal discharge or parasitic loads. Once the charger detects a full battery, it goes into a trickle charge (or float) mode at.6 volts (for AGM batteries, temperature compensated) for the remainder of the day. When the trailer is sitting in the distribution center, not attached to the tractor, the batteries are charged during the day to ensure they are always topped off. Chart D - Trickle Charge of Bateries - 5//20.5.5.5 6:00 6:28 6:56 7:24 7:52 8:20 8:48 9:16 9:44 10: 10:40 11:08 11:36 :04 :32 :00 :28 :56 :24 :52 15:20 15:48 16:16 16:44 17: 17:40 18:08 18:36 19:04 19:32 20:00 20:28 20:56 Time of Day
Conclusion Based on test data collected and comments from the vendor, the issue of insufficient liftgate battery charging was solved with the installation of the echarge 100 Watt Solar Battery Charger. The system ensured that batteries were regularly topped off and ready for a daily delivery cycle. Because the system ensures that batteries are never left in a discharged or partially charged state, battery life should be extended from 1 or 2 years to 3 or 4 years depending on battery type. The payback period is between 1 to 2 years and could be shorter if avoidance of costs for battery maintenance or road service calls is factored in. The echarge 100 Watt Solar Battery Charger is appropriate to augment any alternator based liftgate charging system whether a Trail Charger is used or not. Depending upon average daily usage of the liftgate, it may be possible to charge the liftgate batteries only from solar charger without any electrical connection to the alternator. An echarge 300 watt Solar Battery Charger would eliminate the need for an alternator connection, a larger alternator or the installation of a Trail Charger. 3 Hallene Road, Warwick, RI 02886 p: 866 571 0175 f: 866 935 4883 e: info@enowenergy.com enowenergy.com