Sit-down truck batteries were inspected on 7/16 at Saddle Creek IPSY warehouse at 4600 Railhead Rd, Ft. Worth TX. as elevated temperatures were present. Upon data download, issues were found such as limited charge times and plug-in opportunities. Proceeded to survey the equipment to match chargers with batteries to validate ratio 1 to 1.
Units highlighted in orange are Shoppas rental, blue trucks belong to IPSY. List of fork trucks represent units belonging to IPSY, trucks charging at this location that are assigned to other operations are not listed. However, all chargers recorded conform the whole charging area.
Data download on the 2 batteries was performed. Tracking devices installed permanently have significant amount of data therefore information from 4/1 to 7/15 was selected to present this report. For the most part the operation starts at 6 am through midnight however during the last months, activity has been recorded around the clock.
A difference of settings in such devices group and graph differently and in many cases, data had to be analyzed manually to provide graphic representation of the findings.
Opportunity charge profile is suitable for any battery usage (white bar %) below the green line. Amount of discharge hours also determines if OPP charge profile is the best option. Fast charge profile is determined when battery usage is below the 160% (red line) but above the 120%. Saturday 5/30 was the most utilized day with 123%.
Run time chart on the right shows the number of hours each day this fork truck was operated being 7/9 the highest at 15.3 hours.
Graph on the left displays charge events per day. 4 times is the maximum happening only 3 times in 3.5 months. Most of days only 1 time the charging occurred.
Chart on the right represents hours of charging which is the aggregate of all plug-ins per day. The yellow trending line clearly underlines a decreasing trending line in charge hours. Chart below demonstrates battery voltage surpassing the 30 and 20 percent discharge level and even deeper over discharged state.
Considering the long hours of operation, limited plug-in occurrences and short charge times; battery is experiencing elevated temperatures due to low voltage. On any opportunity/fast charge applications it is essential to introduce charging events and maintain higher voltage levels on batteries. The rule is to achieve voltage levels from 30% to 80% by plugging to recharge during every break, lunch and shift changes.
Continuing this path without any changes will cause battery to fail due to sulfation (Acid trapped inside of plates unable to be released to successfully bring voltage to 100%). In time, temperatures will raise triggering internal plates to disintegrate and lose AH capacity.
7/8 shows to be the heaviest day at a utilization of 128% (red bars). Some days a charge deficit displayed by red bars higher than the green ones. (discharge vs. charge). Yellow bars show plug-in occurrences being 7 times the most on 7/8 and 7/9. The rest of the time 2 or 3 times a day seems to be the average with some days a critical single time of recharge.
Battery is consistently over discharged with only a couple of times recharged fully in 3.5 months. Its health is being compromised producing weakness in cells ending in premature failure.
There are 30 warnings of over discharge, 56 critical alerts (deeper and more severe) of over discharge and 51 registered low water alerts.
Lack of consistent watering program (once a week, every week after a full charge cycle) compounds the problem of heat and deterioration of battery internals.
Picture documented below show forklifts not connected to recharge or parked in front of charger not matched for its voltage/ampere hour capacity. Among other recommendations, charging area needs to be re-organized to group the forklifts belonging to IPSY on one side and also parking the trucks at a 30-degree angle instead of 90 which causes parking the equipment too close to each other and potential damage when pulling out.
Below are the recommendations:
- Match each charger to truck/battery. Voltage/Ampere-Hour Capacity. Connector colors. Currently there are only 4 somewhat clearly marked chargers assigned to trucks. List will be analyzed to make sure all trucks are assigned to the correct charger.
- Assign parking slots to each fork truck. Label trucks/chargers.
- Paint new lines on the floor for easy access and parking.
- Furnish OSHA safety items on each charging are with a 25’ radius of reach. Emergency spill kit, PPE and emergency eye wash station. Main charging is 134’ long.
- Train operators. Safety, watering, charging and all other topics regarding batteries/chargers.
- Encourage (enforce) Plug-in culture to maintain batteries at a higher voltage level
- Document watering schedule to ensure it is happening.
- Ensure all trucks are connected to its charger over the weekend to take advantage of equalize charge.
- Preventive Maintenance Inspections are recommended to optimized and prevent operation interruptions.
- Shoppas will swap conventional chargers (2) with Opportunity chargers to optimize charging patterns.