I went out on a nice bright sunny day a few weeks ago. People around town were waving, shouting, and honking their horns. On my way home, I tried to honk back at one car and found that I couldn’t. On top of that, my the relay for my turn signals was no longer clicking.
Arriving home, I started diagnosing the problem. From what I found, I no longer had operating break lights, turn signals, windshield wipers, and a horn. I replaced a broken fuse, but nothing started operating again[
I’ve been troubleshooting these problems over a few weekends. Today I had my sights set on just getting the horn working. I confirmed that it was still operating by wiring it directly to my fuse block. I located the two wires in the turn signal controls that wire up to the horn. I then ran a wire from the fuse block to the steering wheel, and another wire to the front of the car and onto the horn. The horn now has its own 10 amp dedicated circuit.
The horn works again – but now the headlights and dashboard lights stopped working. Oh what fun times these are. I long for the days that Teddy and I can drive my little car on the streets again.
The weather is warming up and I feel as if I’m slowly coming out of a slumber. It’s always felt a bit too cold to work on the car over the winter. Most of the changes on this blog over the winter have simply been adding books, magazines, and news articles to the research menus.
Now that we are in daylight savings time, it feels like its still light out by time I’m done with work, and it’s been getting warm enough to work in the garage. I’ve even started working outside on the car.
Last week I finished working on getting the break lights working with a backup break sensor that is based on the break pedal moving rather than pressure of the break fluid. I believe the 45 year old diaphragm in the existing sensor may not have the flex needed to move when the breaks are pressed. In addition, I believe replacing the lead acid batteries with Lithium has shaved a few hundred pounds from the car – requiring less pressure on the breaks.
CitiCar Break Switch Replacement
Now that the break lights are fixed, I’ve started driving the car around town. We’ve had great weather for it.
I’ve been composing a large list of things that I need to work on, so there is plenty to do this Spring/Summer.
The weather is getting colder and the daylight is getting shorter, especially with daylight savings time. The garage is a bit cold to work on the car. I’ve been staying inside focusing more on the solar system and some custom software I’ve written.
Inverter
An inverter capable of charging the CitiCar
In my previous post, I ran into problems charging the car with a 1000 watt inverter powered by the lead acid batteries that came with the car. I went ahead and purchased a cheap inverter that was capable of continuously delivering 3500 watts.
The inverter had no trouble while charging the car. I thought it may only last a half hour at first, then an hour, and another hour… eventually Teddy and I had to take the car down to the Fireball Arcade. We had exclusive access while they were closed to play some games, show off the CitiCar, and talk about maybe driving it in the Christmas parade. The batteries in the car went from a 76% charge to 93%.
The charger had a draw around 850 watts for almost three hours. Ignoring the efficiency of the inverter, charger, EVSE, and working with ballpark figures, it turns out the batteries can store at least 53 amp hours each. However, keep in mind the batteries were still running fine when I had to take off. I may end up getting a capacity monitor for the battery bank as well.
inverter voltage
120
amps
5
watts (volts * amps)
850
hours
3
watt hours (watts * hours)
2,550
battery voltage
12
battery bank amp hours (watt hours / volts)
212
battery count
4
battery amp hours (battery bank amp hours / count)
53
I have a few inverters now.
Brand
Sign Wave
Watts
Surge
Per Outlet
Direct
Efficency
Cen-tech
Modulated
400
800
N/A
87%
Sunforce
Pure
1000
2000
500
N/A
90%
EDECOA
Pure
3500
7000
1800
3500
88%
There are a few things I’ve learned about inverters over the years.
Sparks
The first time you connect the inverter to the battery, you’ll see and hear a spark. An inverter has capacitors that will fill up fairly quick. If you tap the wire against the post again, you’ll probably see that there are no longer any sparks.
It’s a good idea to have a switch to cut off the battery from your inverter. A switch is meant to handle these sparks. Not probable, but in a worst case scenario, your cable will be fused to the post, or you’ll have melted bits of metal flying into your eye.
When I disconnect an inverter from a battery, I usually turn it on afterwards to drain the capacitors. It will come on briefly and beep to warn you about low voltage. Afterwards, I turn it off again and set it to the side.
Watts
The watt rating is often misleading, representing a sum. My Sunforce 1000 watt inverter could only deliver 500 watts per outlet, and therefore would not allow me to charge my car with 850 watts.
If the inverter pulls more current than your batteries can handle, it may also appear that the inverter is unable to support its advertised wattage since it may shut off as a low voltage protection feature to prevent damaging your batteries.
You may want to tear your inverter apart and verify the wire to the outlet can support the amps needed.
Grounding
Grounding is specifically used to protect your equipment from surges.
A receptacle tester indicating an open ground
Using a receptacle tester, some inverters will show that you’ll have an open ground fault. My Sunforce inverter showed that it was wired up correctly, even though I didn’t wire it up for grounding. The Cen-Tech and EDECOA inverters had an open ground fault.
Inverters will usually have a specific area to connect a ground wire to them, or to simply connect to the body. The EDECOA inverter simply says to connect it to the body and gives you a little grounding clip. The Sunforce inverter has a labeled screw on the back. The Cen-Tech inverter has nothing on it’s plastic shell that would be conductive.
Inverters are used in two places – vehicles and structures.
The rubber tires on a vehicle will cause too much impedance to reach the ground, so it’s often recommended to connect to a specific part or the body of the inverter to the frame of a vehicle – but only if its a negative ground. A vehicles frame is often connected directly to the car batteries negative terminal to cut down on the wires needed to be ran through a car.
For structures, you’ll often have at least one eight foot grounding rod driven vertically into the earth. You’ll often be connected from the inverter to the ground rod to lower impedance.
Sometimes it’s a losing battle trying to figure out how to ground an inverter. The EDECOA inverter was a head ache, and still boggles my mind. The only way I was able to get the open ground fault to go away was when I probed the ground and neutral terminal screws for continuity. I tried connecting my houses grounding rod to various parts on the inverter without any luck.
Sign Waves
AC (Alternating Current) electricity is provided by the utility company. The voltage flip flops between negative and positive, and shows up on an oscilloscope as a bunch of round hills. An inverters job is to convert DC (Direct current) electricity into the same wave form, at the same voltage and frequency.
Modulated Sign Wave
The cheaper inverters often generate a modulated sign wave. They are simple to make and don’t require much hardware. The signal appears to look like stairs going up and down – or outlines of 8-bit hills. The more steps you have, the better the inverter is for your equipment. However, not every modulated sign wave is a perfect set of stairs.
This can run things like motors in a fan, drill, table saw, and incandescent light bulbs. Unfortunately a modulated sign wave can damage electronic equipment such as computers and battery chargers.
Modulated sign wave from 400 watt CEN-TECH inverter
Pure Sign Wave
Also known as a true sign wave, this signal matches what a utility company provides. Your devices may depend on a pure sign wave that looks like smooth curves to regulate clock cycles, capacitors, and trigger events when various voltages are recognized. Inverters will use more components to smooth out the stair pattern into a gradual curve. Inverters that advertise that they offer a pure sign wave, may still appear to be stepped, but at a very refined scale.
Pure sign wave from 1000 watt Sunforce inverter
Pure sign wave from 3500 watt EDECOA inverter
How to choose
To avoid any potential problems, it’s usually best to go with a pure sign wave inverter, as that is what the manufacturer of your devices designed it for. If you are in a pinch, you may want to try the modified inverters. I would only recommend it if you are using simple equipment that doesn’t have a computer in it (power tools, coffee maker, incandescent lights). I’ve had electronics damaged from using the CEN-TECH inverter from Harbor Freight.
I used a Rigol DS1054Z digital oscilloscope to capture the sign waves from each of my inverters. The lines appear “fuzzy”. I believe this is because my scope is not isolated from the noise on the houses AC power from the utility company.
Plug with terminal leads for testing
I also made my own plug to test the signal. I had an old plug from a battery charger that went bad. I stripped the wire and put male blade terminals on the end to prevent the two wires from touching themselves or me. I marked the hot wire (thin blade) in red electric tape. From here, I was able to connect my probe to the hot wire and attach the probes grounding clip on the neutral wires terminal.
Recharge
It’s been a week, and my battery bank is still recovering. At first, I was using the solar panels to charge up my battery bank. I have a few things going against me.
Amorphous Solar Panels
200 watt array
Amorphous
Approaching shortest day of the year
Moved about 350 miles towards the north pole
Area has shadows throughout the day
Bad vertical/horizontal angle & no sun tracking
A few days of rain and overcast
Long cord
Batteries are cool (60 degrees Fahrenheit)
I started to charge the battery bank with a 12v 4amp trickle charger when the sun is down. With MPPT, my solar panels can make better use of the voltage during the day.
Solar charger only reports charging via panels, but recognizes voltage increases
When the batteries were in the car, I could recharge them in eight hours with the same charger – but each battery in series had its own 12 volt charger. In this setup, I can’t hook up four 12 volt chargers in parallel.
Five trickle battery chargers for motor and accessories
I’ve adjusted the panels to draw more power from the sun, but I’m fairly limited in where they are located at the moment. I’ve ordered 500 watts of polycrystalline solar panels. On days with rain, I didn’t bother hooking up the panels and stuck with the trickle charger.
I’m a bit interested in how to track the sun as well as putting a shed in the back yard for the panels.
Erratic Temperatures
When I first started charging the battery bank, I noticed the charge controller was reporting temperatures that were jumping up and down on a graph.
The remote battery sensor starts jumping up and down overnight
Initially, I thought this was a result of the battery trickle charger being too close to the temperature sensor and moved it further away. It had no effect on the temperature.
After a little research, what I found out is that the signal from thermocouple temperature sensors are affected by coupling from AC power running along in parallel. Sure enough, as soon as I unplugged the battery charger, the solar charge controllers remote battery sensor went back to a strait line.
Noise from AC coupling has been reduced after movements
I went ahead and started moving wires around to see if I could remove the coupling. When I moved the heat sensor with my warm hands, it showed up as a peak since the garage is fairly cool this time of year. It gave me a good point of reference.
I was successful in reducing the coupling noise when moving wires perpendicular to each other. I went back and tried to improve the position of everything a second time, but I suspect that maybe the trickle charger itself is having an affect in the signal of how it charges, some coupling is getting through regardless if the wires are parallel, or works from a greater distance than I realize.
The good new is that I understand what is causing it, and that the temperature sensor is still fairly close to the temperature without affecting the charge controllers charging voltage.
Solar Pi
I’ve been taking a closer look at my old software and found that the real-time data was in a separate folder.
RS485 Logger and Wi-Fi devices
The first round of the software was working from a static CSV file that involved a manual process to retrieve the data and publish in the repository. The device was an eLOG01 and even had its own CR1220 backup battery.
Initially I tried a little device to let me access the data over Wi-Fi. The eBox-WIFI-01 device had its own Wi-Fi network to connect to. I ran into a few problems and ended up looking into other options.
Real-Time Logs
Raspberry Pi with battery backup connects to the solar charge controllers data port
The next round made use of a Raspberry Pi and connecting to the data port via RS485 using the modbus protocol. I then started polling the controller every minute and saving its settings to a MySQL database.
It’s this website that I’ve been monitoring quite closely with temperatures and power with the load, pv array, and battery. The only issue is that I keep modifying the code to show the last hour, three hours, and 24 hours. I need to setup the interface to give me an option to do this within my browser.
Battery
The battery tab lets me see how the trickle charger is doing compared to the solar panels. I was debating if I should keep the trickle charger on during the day instead of plugging in the panels. It looks like the panels are a little better than the charge controller.
Battery voltage and charging graphs over the past 24 hours
Load
The load tab lets me see the draw of power by devices connected to the charge controllers 12 volt power supply. The charge controller can be configured to turn the supply off based on the current time, or the sun has risen/set. The raspberry Pi was powered by a usb port from this power source in my original configuration.
With my LED Christmas lights draining a 50 ah wheel chair battery overnight a few years back, I hooked the Raspberry Pi up to a 6000 mAh Jackery Portable Travel Charger as a backup solution. Once the loads power is cut off, the Raspberry Pi is still able to read information from the controller such as how low the battery is, and associated warnings before/if the controller shuts off.
Once this USB battery was connected to the load, I could see its effect on the load. It draws six watts briefly about once an hour, and then it draws six watts over two and a half hours once a day.
Load discharge graphs over the past 24 hours
If you look at the voltage, you’ll notice it also drops a little for a brief moment every hour as well, as it’s tied directly to the battery voltage lowering during its draw.
I’m debating if I should upgrade to a higher voltage battery bank so that the load will have a consistent 12v power supply that does not decrease as the batteries are discharged.
Solar Array
Lately, I monitor the solar array to determine if I should switch over to grid power to continue charging the battery bank. I can set it up to show me how the panels have been doing over the past few days. I’ve been pulling 55 watts at most on a 200 watt system. Notice the peak on the third day is much thinner. I had left the solar panels disconnected in the morning due to rain until things cleared up.
With the low wattage and a larger battery bank then when I first setup the system, I decided to purchase some new panels.
Solar panel power generation graphs over the past five days
Usually I’ll flip between the battery, load, and solar tabs to review where the watts are coming from, and where they are going. I’ll need to setup something that’s a bit more easier to compare the information I’m looking for.
MODBUS Editor
Currently I modify settings on the controller with a device called an MT-50 Remote Meter. I end up removing the raspberry pi data cable and losing track of data while I’m plugged in.
I’ve started working on an editor to modify the settings directly through the raspberry pi website. I’ve got most of everything working to read the data and display lookup lists and input boxes. I’m on the cusp of the actual goal to send write requests to the solar charge controller. The new setup is pretty powerful.
MODBUS interface to configure EPsolar Tracer4120A charge controller
With the old CitiCar batteries laying about, I decided it was about time to embark on a side project to charge my CitiCar with the power of the sun.
Three years ago, I started a little off-grid solar project. I already had everything tucked away in the garage. I brought everything out and started connecting the batteries in parallel, and then to the inverter.
I did a test and verified I could use the inverter to plug things in and power them on. It was only 1000 watts, but I decided to attempt to charge the CitiCar. The inverter started beeping and stopped supplying power.
I thought there was a chance of that happening. It looks like I’ll need an inverter that can supply a minimum of 1800 watts with 15 amps.
Solar Panel Array
I continued to setup the solar charge controller and the solar panels to start charging the battery bank. I had trouble getting the 8-way splitter to work, and ended up using two 4-way splitters to connect seven of the eight panels.
The last part was to connect the Raspberry Pi to log data. I was able to get it up and running on the network over wifi and view the dashboard.
Dashboard of various measurements that the raspberry pi collected from the solar charge controller.
Unfortunately, I couldn’t see any data since the last time I had the system up and running. I was able to update the date in the charge controller, change the time-zone on the raspberry pi, and confirm that data was being saved into the MySQL database.
It turns out that the code that I had written was in its alpha stage while experimenting with the data being returned. It looks like I was using a separate logger to grab CSV files, and then hard-coding the website to load from them instead of the database.
In summary, I need a more powerful inverter, and I need to wire up the website to a website.
Solar EVSE Charging Station – Part 1
Update
After reviewing a few old videos that I had made demonstrating the solarpi website, I found that I was looking at an older interface. The newer interface is wired up to the database and keeps updating itself to show graphs of the last hour of data for each gauge. In addition, the gauges have colors to indicate ideal areas that the needle should be in. The site still needs plenty of improvement as well as a way to view and compare history.
In other news
The current AiLi battery capacity meter keeps resetting to 0% during my drives. I think it’s due to a loose wire on bumpy roads. As a temporary backup solution, II wired up a previous voltage monitor that gives me a percent and graph based on voltage.
The garage is dark. Both lights have now burnt out.
I’ve got a real sense of pride and accomplishment now that the CitiCar is able to drive out on the open road again. I’ve taken it on a few test drives, and I’ve ran into a few issues.
The biggest risk of failure is when there is a change – no matter how small. Hold my beer… I just replaced the entire powertrain with equipment that I was unfamiliar with.
The most notable issue is that the car felt like it lost power quite often. It was a bit annoying having to coast to a safe spot to pull over and diagnose what was happening.
The beginning
Teddy and I went on a test drive into town. We had a great time visiting C&C Frozen Treats, I want Candy, and eating ice cream at the town square. We headed over to McDonalds for a bite to eat and then headed towards home.
It first started where I pressed the throttle and the motor would jolt and turn off. After doing this a few times, I slowly pressed the throttle and was able to continue to drive. I suspected that the motor controller was implementing a fail safe to make sure the throttle high-pedal was off before the resistance changed on the potentiometer, and that there was some kind of race condition. As the CitiCar continued to have trouble a little later, I would keep trying to ease my foot lightly onto the throttle.
No Power
Finally, the motor wouldn’t turn on at all and I ended up coasting into the Knotty Pine restaurants parking lot. I was at a loss. I couldn’t figure out what was going on. I had power for everything else. I could hear the contactors activating when shifting between forward and reverse. I pressed the throttle lightly and heard the main contactor activate. “It’s back!” I thought. My next hypothesis was that maybe there was some kind of additional fail safe where the controller would lock me out of operating it for a couple minutes to protect itself.
Paranoia
Continuing on, I was praying I could get home without calling a tow truck. I was going up hill. I decided to play it safe and take a side street, still going up hill and… I lost power again. Here I was, slowing down going up a hill, and someone was behind me. I was almost at a dead stop when the car drove around me. I was a bit paranoid when I recognized the markings of a police car.
I couldn’t go up hill, so I coasted backwards into a driveway and put on the emergency brake. I was trying to figure out the problem in case the officer came back around to check in on how I was doing. I was there for roughly five minutes, certain that I was stranded. It came back alive and I was off, praying I could get back home.
EV at the Gas Station
I didn’t make it far. As soon as I turned onto the main road, I lost power. I coasted into the new gas station parking lot and just barely got into a nice parking spot. I figured if I was going to be there for awhile, I could grab a bite to eat. The person in the vehicle next to me asked if he could take a photo of the car. We talked a bit and I showed him around the car.
I broke out some alligator clips and a multi-meter and started testing connections. I traced the problem down to a loose connection on the throttle high-pedal contact switch. The wire had almost come off. I pushed it back and it was good to go.
I started to approach the exit and realized the speedometer didn’t have any power. I looked over at the fuse block and saw a light was on. I must have blown the fuse when testing connections with the alligator clips. I pulled off, replaced the fuse, and left the gas station.
Final Stretch
I lost power once more on the way home without much of an area to pull off. I pulled as close to the curb as I could, fixed the issue, and continued on my way.
As I pulled into my subdivision, I was relieved to know that the last half mile was just coasting home. That was the roughest trips I’d ever been on in the CitiCar. Taking a closer look, I noticed the switch’s spade was bent a little, and there was no slack on the wire connected to it. I created an extension wire to add some slack. I noticed the connection felt loose, but I thought nothing of it… until I started running into problems with the next drive.
The Actual Problem
The problem was that the contact switch on the potbox is not as wide as my spade terminals. The female spade terminal was loose and kept falling off.
Snug connectors on throttles high-pedal switch
Pairs of 2.8, 4.8, and 6.3mm spade connectors next to an insulated 6.3 spade connector
I ordered an assortment of spade terminals in various sizes. The 4.8mm female connector fit snug onto the switch. I made a few mistakes trying to crimp a non-insulated terminal. I watched a couple of videos and was able to figure it out.
Stalling ICE
I was thinking what would happen if an ICE car did this – and then I realized it does. The first car I owned was a Dodge Colt. My dad matched half of the price. It was a good car, but it was stalling all the time – at stoplights, and even traveling downhill at 90 mph. I was often having trouble trying to start it back up. I knew nothing about cars, but my dad did. I recall he seemed to be close to figuring out the problem. It really stumped him. Eventually the car ended up in a junk yard. I feel as if the CitiCar is much simpler to troubleshoot. Rather than moving parts, vibration, noises, and fumes – it’s just bare-bones simple electronics.
Alltrax Troubleshooting (and story about contactor)
In other news
I’ve changed both diodes on the forwards and reverse shifter from 1 amp (1N4006) to handle 3 amps (1N5408). In addition, it’s legs are thicker and less susceptible to breaking, causing the same experience with no power to the high-pedal – however one direction would still work until the second diode broke.
The new D&D Motor Systems motor is about five miles slower than the stock motor from the manufacturer.
I’m looking into other options to track speed without GPS.
I’m looking into installing small lights to work on the car easier and show it off.
I might setup the solar charging station / EVSE this weekend. It can also serve as a backup power supply for power outages.
I’ve been learning about field weakening as a potential option to increase the speed of the motor. From what I gather – 2/3 of original nichrome resistor between S1 & S2 terminals on the body of the motor, use a solenoid to turn it on.
Quite a bit has happened since the last post where the majority of my nights and weekends were focused on the CitiCar, and a bit exhausted by time I’m done for the day. The videos were still being posted, but I just didn’t have the mental willpower to write up a detailed account of what was done. here is a brief summary of the last two weeks.
Battery cables
2015 Chevy Volt lithium batteries and charger installed into car and connected in parallel with cables from an old EV and a few battery cables that I made myself from materials provided by a local CitiCar enthusiast.
Battery terminal side-brackets installed.
CitiCar battery cables
Main Fuse & Switch
Installed an ANL fuse box to hold the 400 amp ANN fuse. “Sculpted” the cover to make it fit over the thick 2/0 cables and lugs connected to it.
Installed a heavy duty switch to disconnect the power that could handle the large number of amps that the motor will draw from the batteries. Purchased some screws at the hardware store to mount the switch.
Continuing to add cables along the path from the positive battery terminal to a switch, fuse, contactor, etc. Cleaning battery acid from cable lugs donated from another EV.
Main Fuse & Switch
Fuse box mount
Created a backplate to mount a new 12 volt fuse block out of diamond plate aluminum, and mounted it into the car where the accessory battery had previously sat.
Wired up chargers charging wires. Zip-tied the extension cable going to the J1772 adapter along the cars frame. Ran 10 gauge wire to the front of the car, specifically to run the 12 volt DC-to-DC converter and to control the motor controller and contactors from the dashboard.
CitiCar Fuse Box Mount
Installing DC2DC
Wrapped power supply cable to the front of the car with split tubing to protect it.
Installed a 20 amp 12 volt power supply in the CitiCar to convert the batteries 48v power supply to 12v. At most, it can handle 240 watts.
Added a LED light strip with a switch.
Installing DC2DC
Powered Dashboard
Connect the dashboard to the 12v fuse block. Wire up the frame to the 12v negative. The cabin light is unable to get power. The original contactors are still activating.
Powered Dashboard
Wires and Switches
Painting battery cables red. Starting to prepare other cables to paint.
Comparing two separate motor reversing SW202 style switches. Changing from 12v coils to 48v coils to simplify wiring and reduce the need for relays.
Change the old 120v charger cable into an extension cord by adding a NEMA 5-20R receptacle socket. Added a second charging cable plug to the car so that the batteries can be charged via J1772 in the back, or 120v on the side by changing which cord is plugged into the back of the charger.
Wires and Switches
Painting Battery Cables
Painting battery cables with Plasti Dip to indicate how they are connected to the batteries. Added heat shrink where it was missing. Cut off rubber terminal covers. Wrapped up terminal ends with painters tape.
Red – Positive, and motor A1
Black – Negative, and motor A2
White – Motor Negative
Blue – Motor S1
Green – Motor S2
Painting battery covers.
Paintiing Battery Cables
Plasti Dip Battery Modules
Continuing painting battery cables and the battery covers on the 2015 Chevy Volt battery modules. Problems with using painting tape to paint two colors of Plasti Dip, as well as an unexpected early morning rain getting things wet. Cleaning up and painting battery modules blue for a more appealing look. Finish painting the battery cables.
Plastic Dip Battery Modules
Finish Battery & Cables Paint
Finish painting the battery volt modules and peel off the painters tape. Clean and neutralize battery acid on battery cable lugs.
Clean and neutralize acid on passenger side battery box floor. Start laying down thermal layer and toolbox liner.
Improve technique to peel painters tape from wet Plasti Dip to have nice hard edges.
Added some corrasion/oxidizing protector to battery cable lugs and battery box floor.
Finish Battery & Cables Paint
Battery Box Liner
Line the battery compartment of the CitiCar with toolbox liner. The liner is preferred because it is non-conductive. The frame of the car is conductive and wired to the battery negative, so this helps prevent a short in case a battery positive wire accidentally touches the frame. The thermal barrier may help with battery temperatures and a little extra padding for bumpy rides.
Drivers side was neutralized. Corrosion protector was removed, as it left an oily residue and wouldn’t be suitable for applying adhesives to keep the toolbox liner attached.
Battery Box Liner
High Voltage Stickers
Created some battery labels to warn about high voltage, and to provide details about the batteries.
Creating High Voltage Stickers
Drivers Side Batteries Installed
Re-installing the drivers side painted batteries, main switch, and fuse after lining the battery box with toolbox liner.
Drivers Side Batteries Installed
Battery Terminal Caps
Cut motor mounting brackets down further with new diamond cutting wheels. More battery cables were installed. Created caps to protect exposed terminals from moldable plastic that melts in warm water. Installed shunt in a different position for easier access to plug in wires.
Battery Terminal Caps
Powertrain Test
Wired up the motor and motor reversing switch. Setup switch and diodes on the front of the car to activate the contactors and let the motor controller know if the vehicle is moving in reverse.
Powertrain Test
CitiCar Runs Again
Troubleshoot contactor activation. Reverse direction of Forward/Reverse diodes. Got the wheels to spin (and in the correct direction). Go on a test drive.
CitiCar Runs Again
Alltrax Troubleshooting
Configure motor controller to accelerate faster, adjust voltage limits, and provide more amps to the motor. Since the motor was just replaced, I topped off the differential fluid. The speedometer wasn’t turning on, so I replaced it with a spare that I had laying around. Drove into town and ran into problems on the way back home with a burnt fuse and a disconnected high-pedal switch on the throttle.
The J1772 inlet has been installed onto the tail end of the CitiCar. I no longer need to unlock the trunk and drag out a socket on the end of a long cord to plug in.
The body of the car only offers a few places to put the socket. My original goal was to install it next to the exiting inlet for power from the house. The area surrounding it was obstructed by the door hinges on the inside, or had “electric” written in vinyl on the outside of the car.
I settled for a ridged area by the passenger tail light in the back. There are holes by the contactors that were originally used for the battery and motor cables. I can thread the cable from the adapter to the charger.
CitiCar J1772 Installation
Removing Wires
A fuel gauge from a CitiCar reads from 14 to 19 volts
I removed the three wires from the battery compartment all the way to the dashboard. One was already identified as being for the volt meter. The thicker wires were discovered to lead up to the charger.
While I was at it, I removed the volt meter and found that it had a round hole in the dashboard behind it as opposed to a square hole to match its shape. The hole is too small for the AiLi volt meter. I would prefer to keep the original volt meter and try to control the voltage fed to it with an Arduino to represent the capacity rather than the voltage.
Wiring Harness
Wires brought back to the battery box through a split loom
Wires were thread from the font of the car to the battery compartment through a split loom zip-tied to the aluminum frame. I drilled a hole slightly behind and to the left of the throttle to pass all of the wires through. They connect up to the motor controller and the reversing switch. Short extensions were setup for each connection so that I don’t need to reach into tight spaces to disconnect the wires.
Fix spliced wire with a network keystone jack
When I was trimming the excess split loom tube within the CitiCars battery box, I cut through one of the cables still inside. It was the AiLi battery monitor cable. The cable contains 4 tiny wires, surrounded by strands of what appears to be another line acting as a shield. I had some left over networking Cat6 connectors and keystones and wires up each side to make a solid connection.
Battery monitor still works after fixing wire with network connectors
I was able to hook one of the Chevy volt batteries up with a dc-to-dc converter and a light to confirm that the AiLi meter was reading the correct voltage and change in current as I flipped the switch on and off.
This wasn’t so bad after all. I would have probably ended up doing this anyway. The wire was too short to reach the shunt to begin with. Now that everything has a network connector, I can create an extension cord to reach the shunt in its final position.
Racing Use Only
Racing switch panel
One of my favorite pieces of flair is the racing switch panel for a car that can’t go faster than 35 mph. I got out my old label maker and labeled the different switches. Each switch is a project on its own.
AMPS
The “AMPS” is the “User Mode” wire on the motor controller to let it switch driving profiles. A driving profile can change the maximum amps the motor is allowed to draw.
START
I’m considering how to approach this. I have the CitiCar play a sound of an engine revving up to race, or play a random list of custom sounds.
RUN
The run switch is to turn on the 12 volt DC-to-DC 12 volt converter to use the lights, fans, horn, etc. The car will not operate without this being flipped up.
3SPD
The is going to setup the car so that the motor controller only sees three different positions when the throttle is pressed. It will also allow the original contactors to activate. It will mimic the speed and sound of the original motor controller in the CitiCar.
RDO
This is the power to turn on the radio and amp.
In other news
I ordered some battery side terminals that another C-Car owner has proposed.
I purchased another SW202 switch, but with 48 volt coils. I will no longer need to use relays to provide 12 volt power to the coils.
I’ve composed a document asking the community for help setting up a maker space and talked to a couple people about it.
Hello,
I need help setting up a “Maker Space” within, or near the town of Front Royal, Virginia.
A maker space is a collaborative workspace with a wide variety of equipment available to use that would otherwise be inaccessible to the general public due to costs, electrical requirements, zoning, noise, ventilation, and space. A maker space may consist of a wood shop, machine shop, electronics workstation, 3D printers, computers, embroidery machines, and even Lego building blocks. This educational building’s purpose will be to have fun making stuff, and learn from others making stuff.
I attended the Art Institute of Pittsburgh in 1994, majoring in Industrial Design Technology on a scholarship. I long for the days having access again to a large workshop with a very wide range of industrial equipment. I also went to Mineral County Technical Center in West Virginia for Carpentry, and loved the computer lab along with the art, shop, and mechanical drafting classes throughout middle and high school. My profession took off with the information technology (IT) industry programming software, but I have always retained my creativity making things at home.
Like many others, I often find myself justifying the need to purchase a new tool, machine, or a large surplus of supplies that may have limited use to me. Afterwards, these products collect dust in the garage until someone “borrows” it, to then collect dust in their own garage. As tools, materials, and past projects accumulate, it becomes difficult to find space to store them while keeping my workspace clear of debris.
Some maker spaces not only provide a workshop, but also rent out storage and artist spaces for your own personal work area or show room within the building, providing members 24/7 access. In addition, many offer classes and training, including STEM educational programs.
I can not do this alone. I have a goal, but this is bigger than me. My intent is to set this up as a non-profit organization. Because a maker space can expand and offer such a wide range of equipment and materials to adults and children, I am looking for help from the community.
● Form a board of directors and a mission ● Draw out makers already within the community ● Identify community needs & interests ● Provide ideas & imagination ● Find funding & sponsorship ● Consolidate and acquire equipment, tools, and materials ● Find a location for light industrial use
A small fuse block arrived that can mount directly to a terminal, but offers only four fuses. I picked this up for the 48 volt system since there are not many things that the larger system voltage is needed for.
A small terminal block hooked up to a few devices.
At the moment, I have a fuse for the DC-to-DC converter, Battery Capacity Monitor, and the battery Charger. The last spot will be for the combination of the key switch, main contactor solenoid, and reverse input. There are also relays for forward/reverse that allow 12 volts to activate the coils on the SW202 switch. I may eventually setup a second DC-to-DC converter that sits behind the dashboard.
In Other News
I’ve been reaching out to a few local business owners, looking into setting up a makerspace in my town.
Most of yesterday and the entire day today was full of rain. I wasn’t able to get much done compared to Saturday. Most of the day has been spent planning, researching, and cleaning the garage.
Alltrax Wiring
I’m working in a tight space with the motor controller, contactor, and motor. It’s difficult to bend thick cables, and harder to work with thick terminals overlapping each other.
I was in a tough spot with trying to get two wires connecting to the motor controller, and I was wondering if it was important that the wire from the motor goes to the controller, rather than directly to the contactor. Electrically, it didn’t seem to make much of a difference.
Alternative wiring proposal
C-Car and one DIY EV conversion owner said their controllers were wired up in this way. I sent an email out out the manufacturer.
Wiring Question
Hello.
I have an SR-72500 Motor Controller.
I am installing this in a CitiCar, which was previously controlled by applying 3 different voltages to the motor.
I’m looking at the Generic Series /w SW202 Reverse wire schematic in the operators manual SR (page 22)
On all diagrams in the manual, I see: 1 wire going from the SW180 contactor to the motor controller B+ terminal 1 wire going from the motor controller B+ terminal to the series motor A1 terminal
I’m working in a tight space and it’s difficult to get two lugs onto the B+ terminal.
Can I have the wire to the motor come directly from the SW180 contactor? These are the changes I am proposing:
keep 1 wire going from the SW180 contactor to the motor controller B+ terminal (no change) add 1 wire going from the SW180 contactor to the series motor A1 terminal remove 1 wire going from the motor controller B+ terminal to the series motor A1 terminal
The Answer
Technically speaking it will work, electrically speaking you’re going to cause an issue doing that. If this was a low current system, like a stereo then this would be fine, but since we’re low voltage high current we have to know where current is at all times. So when you put the two wire connection on the solenoid it turns the motor and controller into two separate loads the moment the solenoid closes and both are fighting to get the current coming out. Motor is bigger, it gets the current, and the controller just watches things happen without doing its job.
If you wire it that way, it will operate though, it may just do some weird things randomly.
I was taken back a bit. I half expected a basic answer of something along the lines of – only wire it the way we say to do it. This person went into detail of “WHY” with a simplified explanation. It’s exactly the answer I needed. I actually feel like I learned something.
I posted the manufacturers response on the Facebook post for the other C-Car owners to learn about as well.
Motor Cables
Yesterday I was able to put some cables onto the motor, switches, and controller. I wired up the main contactor solenoid to the motor controller and a small switch as a safety measure to prevent the solenoid from being activated while working on it.
The main contactor was flipped to allow the cable to the controller to be made shorter. The suppression diode was too close to the metal mount for the SW202 switch, so I bent it into a new shape that actually made it a bit more ridged and let me get my hands down into the area much easier.
I also started to setup a couple relays to allow 12 volts to pass to either side of the SW202 switch based on if the car is going in forward or reverse. While I was at it, I started labeling the wires so it would be easier to figure out how to connect everything up once I started running wires from the dashboard.
Cables installed allowing power to transfer between the main contactor, motor controller, motor reversing switch, and the motor.
Search for Parts
I found that out of 10 colors of automotive wire, I didn’t have pink. Pink is used to identify power for “reverse”. I went to a hardware, automotive, and farm supply store and couldn’t find the following:
Pink automotive wire
Relay with a 12v coil to pass 48v over the switch (actually, I couldn’t find any relays)
Battery side wall terminal
I’ve never really looked around an automotive store in the past. Usually I order something online and go to pick it up. I was shocked at how little the store seemed to have.
Gutting Old Parts
I pulled out the 48 volt and 12 volt battery chargers. I started removing all of the loose wires inside the battery compartment under the seat. I’ve got three of the original wires unthreaded from most of the zip ties leading to the front of the car. I was starting to run into a difficult time in the front part of the car.
The vent from the motor to the flap has been removed. I need to determine how to heat and defrost the car now that the motor can not support it.
Lithium Ion
Four battery modules from a 2015 Chevy Volt can fit into the CitiCar
I placed all four lithium battery modules in the car and found that I had enough room to place the battery charger under the seat as well. I’m considering the best placement while considering where the J-1772 inlet can be installed.
The battery modules had little nubs on the side that prevented them from sitting flush against the car. I cut them off and they now sit flush, giving an extra quarter inch to the space available beside them. I also noticed that the two newer chargers are missing the black cable that connects to the battery charger. I’ve been thinking about mounting some small angle brackets to the bottom of the battery box to prevent the modules from moving around while driving.
I’m still thinking about how to connect the four batteries. Each terminal is difficult to reach with the thick 2/0 wire terminals. I was considering adding a terminal fuse to each battery to have something to bolt onto for easier access. I also saw a copper butt seam flag connector as well that might work, letting me create two large wires rather than 10 smaller ones to connect them all together.
The majority of the day was spent replacing the stock General Electric 48 volt motor with the ES-40D-56 from D & D Motor Systems. A local CitiCar enthusiast handed me a set of ramps from his garage, and it helped make the process of jacking up the car a bit quicker.
The first thing I did was to dethatch and remove the lead acid batteries.
A little boo boo from the motors weight
The process of taking the motor off of the car went pretty quick. I was aware of the seal that I had the break, and that I would have to be ready to catch differential fluid. Just like last time, the final step of lowering the motor from the car proved to be a bit difficult. My pinky finger ended up being crushed for a brief moment with 60 pounds of copper.
I had a question that I shot over to the C-Car community in how I could add the intake vent onto the new motor. In the meantime, I moved to the next thing I could tackle.
Removing cables
I started removing every battery and motor cable from the car. I was surprised to find that the main fuse for the motor itself was almost blown. Rather than one, the car had two separate fuses. One of the 250 amps fuses had already blown, and the second was on its last leg.
Fuse labeled as 250V. EAGLE UND LAB LIST 250A
Driving with only one semi-in-tact fuse is a bit concerning. I’ve seen the amps around 250 when starting to go up a hill, and once spiked at 350 amps. If I had continued to drive around with these fuses, I would shortly find myself in quite a pickle.
Controller Nostalgia
Although the motor controller no longer had any of the thick cables connected to it, I was able to confirm that the contactors would activate as I pressed down on the accelerator. I was delighted at the results and decided to keep the contactor.
The main contactor, series contactor, and reversing contactor tower
I’ve got a little project after the conversion to set up a special “user mode” that will activate the contactors while mimicking the original speed jumps/jerking with the motor controller.
Air Intake
I got a few conflicting responses, but the general consensus was that cutting into the case itself would compromise the integrity of the motor. I settled for drilling a few holes into the side of the motor plate, and threading two on the face to attach the original intake.
A rotary tool is used to cut bolts flush with the motor plate
I didn’t attach the vent for air to exit the motor. The D&D Motor has holes along the entire circumference on the other end of the motor. Another approach is needed to evaluate if the air can be captured, or if a different heating source should be used to heat and defrost the CitiCar.
Mounting the Plate
Motor plate with gasket maker around the shaft and each bolt
A thin material was found between the differential and the original motor plate. There was a red sealant in some areas as well.
I cleaned it off with break pad cleaner and then used a gasket maker to draw an outline of silicon around the hole and the bolts.
Afterwards, I tightened everything by hand and let it sit for awhile before tightening with a ratchet.
Motor Bumper
The splined motor bumper
I learned previously that many golf carts often have a spline motor bumper rubber grommet that sits inside the shaft to reduce the vibration of the motor shaft hitting the metal. I didn’t find it in the CitiCar’s stock motor, so I picked one up. I covered it in some grease and stuck it down into the new motors shaft.
New Motor
The last part was actually installing the motor. It was simply lifting it up on the jacks and tightening some bolts. Once the motor was in, I lowered the car. Without any batteries, I pushed it into the garage.
The new D & D Motor Systems ES-40D-56 motor is nestled in its new home
The Chez 