Scroll to bottom of page to see Performance Reports
FORD RANGER EV
IS IMPORTANT TO STAY ALERT AND CAREFULLY OBSERVE ALL HIGH VOLTAGE CAUTIONS/WARNINGS
It is also critically important for anyone who attempts to do their own conversion to realistically appreciate their own abilities and limitations. In other words, one must always recognize what they don't know.
Here are the modified wiring diagrams I created:
~click on the title to view/download~
HIGH VOLTAGE PLUGS:
In order to convert my lead acid Ranger EV to LiFEPO4, I first configured the vehicle to NiMH. I, and most people who have done successful conversions, consider the NiMH algorithm to be the most compatible with LFP cells.
The SLA truck must be in running condition in order to flash the BCM because the program must be able to see all the components to test function. This does not mean the motor is actually running with its wheels turning, it simply means the truck is truly drivable. Further, I learned the hard way that it is important to have the vehicle positioned where it needs to be before the process is started.…once it is up on jack stands, the truck can’t be moved and it has to be close enough to a 220VAC power outlet in order to connect the charger to test the conversion before reinstalling the battery tray. An NGS tester and the flash program (BCM 08/31/99 XL5F-10B687-AH v0 for NiMH), are required to change from a lead acid to a NiMH configuration. I connected the NGS Tester, inserted the card, and followed the instructions on the display.
After completing the flash procedure, I disconnected the 12VDC auxiliary battery and began to drop the pack. Lanny and others have described the procedure in detail so I will only mention a few brief notes. Page 414-03A-120 in the EV Workshop Manual describes the procedure to remove the traction battery pack. However, most of us do not have a hoist or the OEM lift table as described in the manual. I have a battery lift table pallet (PN 502-F003) on which I installed casters of the appropriate weight specs. Others have used a strong metal door. I also use a generic pallet jack to move the pallet away from the truck. After following the wiring disconnect instructions, I positioned my table pallet under the pack and lifted the jack to support it. I then removed the 6 bolts that hold the pack in place and began to lift the truck. I have large jacks in both the front and rear and alternately raise them to keep the truck as level as possible. I also removed the left rear tire to facilitate removing the pack. When the truck frame members were above the pack, I slid the pack out with the pallet jack.
Once the pack was clear of the truck, it was moved to the rear of the vehicle and the case was opened.
Next I removed the high and low voltage wiring, BCM, heaters, battery cables, batteries, and dividers
With the case empty, I then removed the position tabs from the bottom of the case with a heat gun and metal scraper.
After the tray was emptied I began preparing the cells for installation and prioritizing other tasks.
FLOW THROUGH FAN
I installed a new FTF and kept the original recirculation (ventilation fan). I purchased a 12V fan with a flow rate of 175 cfm. It did not have a compatible sense line so I created a work-around to provide it. I think I could have used a variety of other fans that would have worked. In my first conversion, I sealed the FTF off to severely restrict or eliminate airflow through the fan to see what the effect might be. I discovered that there is no discernable difference in recorded temperatures from the NGS whether there was airflow or not. However, I do not drive my EV in the winter and we do not have wide fluctuations in ambient temperature. On the few occasions where the ambient temperature has been very low, I did not experience the significant decrease in range that others have reported.
When I compared 19-1 and 19-2 in the EV Wiring Diagram Manual, I noted that the relay in the Lead Acid vehicle (19-1) already had three of the four wires to function as the FTF relay shown for NiMH (19-2). Therefore, I only needed to add a new power wire to the fan. I cut the WH/RD wire, which was originally on the SLA relay, and used a butt connector and shrink tube to splice in a 14g red power wire to provide 12V to the FTF. I installed the FTF in the front wall of the battery tray with a grill on both sides and attached its black wire to ground. With that part finished, I just needed to create the sense line to complete the installation of the FTF.
For the sense line, I used a 7805 regulator. Terminal 1 is connected to the 12v fan power wire. Terminal 2 is connected to the fan ground wire. Terminal 3 is connected to a 200 ohm 1/4W resistor and a 100 MFD capacitor. The capacitor is connected between terminal 3 and terminal 2. From that point, a 12” 16g yellow wire is attached to pin 6 of C1987. This completes installation of the Flow Through Fan and its sense line.
Since I used the existing relay for the FTF, I needed to add a new relay for the RC Fan. The sense line for the RCF remained as in the original SLA installation as seen in 19-1.
I removed the wire from pin 34, C1986 and moved it to pin 10 of C1987. I removed wire #3852 (BK/LG) from C1984, attached a ¼” spade terminal to it, and connected it to terminal 85 of the new relay. I installed two YE/BK 3”-6” leads with ¼” spade terminals to the existing power line (Y/BK) going to the FTF relay. These two YE/BK leads were then connected to terminals 86 and 87 of the new relay. I also attached a black ground wire pigtail to the black ground wire in the wiring harness going to C1984, to be used later in the installation. I used a short length of wire with a ¼” spade and a butt connector to reattach the WH/RD wire (cut in the FTF installation above) to terminal 30 on the new relay. All wires were attached with crimped butt connectors and shrink tube. At this point, everything was done except to activate the speed control for the recirculating fan.
FAN SPEED CONTROL
I used another 7805 regulator. Terminal 1 is connected to 12Vpower (YE/BK). Terminal 2 is connected to the ground pigtail described above. Terminal 3 is connected to a 200 ohm resistor and a 100MFD capacitor. I cut the OG/LB wire 1” away from C1984 and attached the output line from Terminal 3 of the 7805 regulator to the stub end of the OG/LB wire. I left the remainder of the OG/LB wire in the harness but removed pin 32 from C1986 so it is now a spare wire, disconnected at both ends. In the process of creating all the pigtails, it was necessary to open the harness, which I then retaped.
That completes the fan modifications. The wire providing 12V power to the FTF is the only wire outside the wiring harness. Refer to 19-1 and 19-2 in wiring manual for further information.
As of May 2010 the 1999, with its LiFEPO4 pack, had been driven about 1800 miles. Because of the severe winters and road salt, I do not drive the EVs between October 31 and April 15.
The maximum temperature observed during either charging or discharging was 32C and that was observed on only one occasion. Normally the temp is around 20C. It should be pointed out that the ambient temperature where I live rarely exceeds 85F. For me, in this location, there is no heat problem with the LFP cells. I am using the original vent fan with a speed control modification and added a $20 substitute fan for the flow-through fan with a modified sensor for FTF feedback.
I started out with a range of about 50 miles. My sales contact at HiPower had assured me I would get +/- 75 miles so I hoped the range would increase after the "break-in" period. Unfortunately, the range began to diminish instead. CHP had required me to use their 5 amp charger in order to maintain the warranty, and I suspected it was undercharging the cells. In addition, both chargers failed within a month of use. HP did provide a wiring diagram and parts list so I could repair the chargers, they still did not provide adequate performance. After several communications, CHP finally agreed to allow me to use the Ford on-board charger and keep the warranty in force. With the on-board charger, the range began to stabilize and I hoped that it would improve, but that expectation was overly optimistic. When we added the MiniBMS by CleanPowerAuto, we identified why we were having problems. Multiple cells were exhibiting voltage sag--some within just a few miles of completing a full charge. The voltage sag was more pronounced when the pack was partially discharged and was particularly aggravated by driving more than 50 miles or on grades over 5%. Over the summer of 2010, the range dropped more and more until it was down to +/- 20 miles. The poor range may have been caused by initially using the 5amp charger; there may have been inconsistent or less than ideal cell technology; or the cells were simply not strong enough to power the heavy Ranger on the hilly terrain in my area without voltage sag.
The 1999 was a long struggle but, with invaluable assistance from Chuck Malitz of Pacific Rim Far East, CHP finally replaced the whole pack for the 1999 Ranger in August 2010. CHP sent me 100 of their second generation HP-IFP-W-100ah cells (163mm x 62mm x 282mm 3950 GM), which are larger than the original (160mm x 50mm x 282mm, 3500 GM) and have a 3C discharge rating. When the pack arrived, I could hardly believe my eyes. These new style cell had huge, non-industry standard 19mm posts. They did, however, have special heavy-duty straps to fit those posts plus high torque nuts. These features initially presented as a disadvantage since no connection hardware for the high voltage battery cables is readily available. However, after resolving those issues, the same characteristics have become an advantage. The oversize posts not only act as a heat sink, but they also more easily allow for single cable connections, especially for high voltage, which greatly reduces the chance to develop loose connections. I drilled and tapped holes in the middle of the straps to connect BMS and BCM wires so there are fewer connections on the posts.
To compare specifications for the three generations of HiPower cells, see following documents:
Before I describe the installation of the replacement second generation cells, I will first report on the MiniBMS because this equipment was critical in defining the poor performance issues of the original HP LFP packs.
MiniBMS by CleanPowerAuto
The BMS is available in Individual and Centralized versions. The Individual has boards mounted on each cell and a control panel, mounted in the cab or under the hood, which has a warning buzzer to indicate high or low voltage. There is no LED display visible to the driver. The Centralized version has wires from each cell that connect to a central control board, which is mounted in the cab, and has a warning buzzer plus two LEDs/cell that monitor each cell. Since I already had balancing wires in place from the HP 5amp charger, I used those wires and their aviation plug connectors to install the MiniBMS. This configuration not only worked well for the BMS, but also provided easy access for single-cell charging.
INSTALLING HP-IFP-W-100AH SECOND GENERATION CELLS
GEN 2 PERFORMANCE REPORTS
Winter snows arrived a little late this year so I was able to put about 500 miles on the pack before PennDot started salting the roads. The temperatures were, however, 20-35 degrees. The BMS never indicated voltage sag, even on a 9% grade. I have not pushed the range but after 40-50 mile trips I still had 50% SOC remaining. My wife drove several of the trips with the same results. This is important because she drove partly on the interstate at 55-60 mph with lights, wipers, & heater running.
1999 Ranger EV in winter storage as of December 2, 2010
After a cold winter, spring 2011 finally arrived in mid-April and I put the 1999 Ranger EV back in service. We made three or four 40-50 mile range trips very easily with CSOC showing more than 50%. The pack seemed to be performing the same as it did last fall before the winter storage. In late April I needed to get to a destination that was 50+ miles away. I planned to recharge at the destination because I was going to be there for several hours. The day was rainy with an ambient temperature of 40 F but the trip out was uneventful and part of it was at 60mph. When I arrived, CSOC showed 55% remaining and the odometer read 52 miles and AHC read 94.5. I started charging and went about my business. When I later checked on the truck, I was unpleasantly surprised to see that the charger was not working and I saw Op code 99 on the NGS Tester. I was unable to get the charger working. I realized that it had charged for only a moment or so because there were no changes in the gauges. I was worried that water intrusion had somehow caused damage and I was not all sure if the problem was in the charging station or the on-board charger. Having no other choice, I notified Carol that she may have to come to my rescue and then started the return trip home. I drove this leg much more conservatively than the first. I limited speed to 45 mph, except when I was in traffic that required 55 mph for safety reasons. I had 92 miles on the trip odometer, when the Centralized BMS gave a low voltage signal on one cell. That cell was battery module #12/cell #2. Cell #55 on above charts. The distance-to-empty gauge read 20+ miles and the CSOC gauge read just under 30%. The SOC on the NGS Tester showed 77%. Further, the Ranger diagnostics had not shown any limiting signal on either the DTE gauge or the low-fuel telltale. Nonetheless, I did not want to risk damaging the cell that gave the low voltage signal, so Carol came to tow me home. Once in the garage, I checked the voltage of each cell using the BMS wires, and I was unable to determine which cell had given the low voltage warning. If I had not seen the LED on the centralized BMS, I would not have been able to identify the cell. I then plugged in another charging station. Thankfully, it worked so the problem was in the first charging station and not the vehicle. I fully recharged and, to my surprise, the AHC had increased from 94.5 to 95.8. The following day I made a 60 mile trip quite easily. Although I have not yet tried, I suspect, I could get the round trip of 104 miles if I drove conservatively the whole way, and I might have made it the first time if I had ignored the BMS.
Since then we have been consistently making 60-70 mile trips without difficulty and no evidence of low-voltage cells. We drive at highway speeds up to 60 mph; do not avoid steep terrain; and use lights, wipers, and heater as needed. Essentially, we use this truck exactly the same as an ICE vehicle, except we don’t visit gas stations. So far this pack has met all my expectations and it's performance has been outstanding.
We are consistently getting 80+ miles per charge. Considering that our area has a lot of hills with grades between 6% and 9%, I think this range is excellent. In addition, Carol has driven the truck exclusively for her errands and she does not baby it. It has to go where and how she wants--this means speed, air conditioning/heater, & radio. It is interesting that the range is determined when one single cell goes to a low-voltage state. The SOC and DTE gauges are extremely accurate and linear. When the low-voltage signal occurs, it is always on the same cell and the DTE and SOC gauges read 25 miles-to-empty and 25% remaining. I suspect if this particular cell were replaced, the range might well increase significantly. During the entire season, we did not see temperatures above 35C. Range diminished by less than 5% when ambient temperatures were at 32F. Pack temps were in single digits (7-9C)
When the Gen II pack was first installed, about 75 of the 100 cells achieved equalization voltage before the charger turned off. The more I recharged, the number of cells reaching equalization voltage increased. Now, all 100 cells reach equalization prior to full-charge automatic shutdown with nearly every charge.
All 100 Cells At Equalization Voltage-indicated by both green and red LEDs on
In August, I replaced the coolant pump and revised the software for the NGS2 so it no longer corrupts the SD card. In September, I repaired the blend door motor. Between April and September, we put 8,106 miles on the odometer.
In October I replaced the oil pump for the electric motor. From October 1 through December 2, we added another 2,200 miles to the odometer. We are still getting a range of 80 miles but sadly, winter is nearly here. It sure was nice to pass by the gas stations all summer long but now the truck is going in to storage for a long winter's nap.