Charles Morris spotted of video of The Chez during its first use of a public charging station last year. At the time, the CitiCar was using a few trickle chargers when it still had lead acid batteries. Since it was parked next to a Tesla, it caught a lot of attention. They posted an article about CitiCar’s in general and and embedded my video to show that “a few may even be plying the roads somewhere.” (C. Morris, 2021) on EVANNEX®, which in turn was picked up and syndicated on both CleanTechnica and InsideEVs.
My Video on YouTube
CitiCar at EV charging station
September 15, 2020
Tesla Destination Charger, Front Roya, Virginia
Long before Tesla, there was another legendary electric car back in the 1970s
CitiCar, Electric Vehicles, Tesla
September 30, 2021
The Next Web, Classic Car History
The Legendary Electric Car From The 1970s That Lead US Electric Car Sales Until Tesla Came Along
Here’s some good electric classic car history for you.
Charles Morris (Guest Contributor)
September 30, 2021
Long Before Tesla, In The 1970s, There Was Another Legendary EV
Yes, EVs date back much further than some people realize.
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.
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.
It’s been a full week since I had initially charged the CitiCar lithium batteries with an inverter connected to the old lead acid batteries. The lead acid batteries were drained just below 12 volts after three hours of charge.
After seven days of charging, the battery bank has been restored to being fully charged. The 200 watts of solar panels were not even producing 60 watts at peak sunlight in the middle of winter.
The batteries were not recovering much during the day. After a couple days, I added a 4 amp car battery charger/maintainer to continue the charge during the night, rainy days, and when there wasn’t much power from the sun.
At this moment, I’m not fully running on the power of the sun. Even though I may have a large battery bank, it’s problematic if it takes a few days to recover on the sun alone. My goal is to get this battery bank to charge with one day of sun power. I’m under the impression that would need to capture around 3.6 kWh in one day.
I found a Casio online calculator that gave me an idea of having roughly seven sunshine hours this time of year in my location. I would need panels that produce an average of 514 watts throughout the day. The actual wattage of solar panels needed to produce 500 watts at this time of year feels like 2 or 3 kilowatts when looking at my amorphous panels only producing a quarter of what they are rated for, and in a much smaller window than seven hours.
I ordered 500 watts of polycrystalline panels along with another charge controller. I’ll need to look into having a small shed setup in the back yard to mount the panels to the roof.
From what I understand, you shouldn’t mix and match solar panels wired up to your charge controller. However, you can hook up multiple charge controllers to the same battery bank – and you don’t need to wire them up to talk to each other either. I’ll be experimenting with this to make use of the 700 watts I’ll have in total.
Still puzzled over the noise with the temperature probe, I started doing a bit more reading and experimenting.
I was trying to figure out if there was a specific area a temperature probe should be. I had assumed to put it in the center of the battery bank, dangling halfway above the floor and the top of the battery. I found an exchange of messages on one forum where someone replied that it should be in the center of mass. I also found an article describing that most battery temperature probes are under the battery where the battery heats up the most. I decided to prop the batteries up a little and stick the probe underneath. This helped, but only a little.
I started looking into ways to shield the cable. I put some extra non-conductive toolbox liner under the probe and its wires. This had a significant impact. It was still noisy, so I tried adding another layer under the wires. I had even more success. Next I tried covering the wires from the top as well, but I couldn’t see any significant impact.
I noticed that the battery charger dropped it’s voltage this afternoon, and is reporting that the battery bank is now fully charged. The chart for voltage is now showing a range of 0.2 instead of 2 volts. This in turn, magnified some “noise” on the voltage chart as well.
I decided to take a deeper look with the oscilloscope. Probing the most positive battery terminal, I saw a pure sign wave. Probing the positive screw terminal of the temperature sensor revealed the same sign wave. The sign wave went away when the charger was unplugged.
I had my answer. There was simply nothing I could do about it other than to stop using the charger if I wanted a clean reading. Looking at the charger itself, It’s actually labeled rite there below the voltage reading:
High frequency battery charger/maintainer
Although it appears as if I have noise on the line, it’s actually a high frequency sign wave of voltage supplied by the charge controller. Since I’m reading the temperature from the charge controller only once a minute, it will seemingly give a random value between the sign waves highest and lowest peak.
What really stumped me was that two temperatures are always the same – Battery and Remote Battery. When the charger is on, they have different values. This tells me that the frequency is so high that the charge controller itself is requesting these two values from the probe, and that the voltage dropped/raised so quickly that the second check (microseconds later) is out of sync.
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.
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.
watts (volts * amps)
watt hours (watts * hours)
battery bank amp hours (watt hours / volts)
battery amp hours (battery bank amp hours / count)
I have a few inverters now.
There are a few things I’ve learned about inverters over the years.
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.
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 is specifically used to protect your equipment from surges.
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.
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.
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.
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.
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.
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.
200 watt array
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
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.
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.
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.
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.
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.
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.
I’ve been taking a closer look at my old software and found that the real-time data was in a separate folder.
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.
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.
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.
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.
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.
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.
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.
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.
I’ve been digging into the history of Robert G. Beaumont and the CitiCar over the past few days. You’ll notice that the side-links on this site now show a link for the Vanguard I Utility Vehicle, and the Vanguard II Sport Coupe. You’ll also notice that I’m separating newspapers by year. They still need a bit of work, but I’m finding bits and pieces little by little, and trying to write up a summary of what I find. I’m in the middle of looking up newspaper articles from ’74.
Not much news regarding the CitiCar. Here are a few highlights
The AiLi capacity meter continues to keep resetting. The additional voltage meter has been very helpful as a backup solution to calculate SoC based on voltage.
To charge from the sun, I need an inverter that can deliver 1800 watts to an outlet. It appears that I would be spending at least $500 for a cheap inverter – but it would be suspect if a single outlet could deliver 15 amps.
I’ve replaced the light bulbs in my garage.
I’m starting to clean up the garage.
I was able to get the speed of the new motor up to 31 mph.
I topped off the differential fluid.
The motor has been making an odd sound when you are at 30 mph and press the throttle.
I started to dream up ideas of how to setup field weakening with a contact switch and my old 1st gear nichrome resistor between the S1/S2 terminals. I want to store it in a box that looks like a flux capacitor, while also being able to manually adjust the resistance.
I ordered a 4 pole switch so I could disable the original contactors from activating.
I ordered a motorcycle speedometer that detects how fast a wheel is spinning with magnets.
I ordered a speed sensor to detect how fast the motors armature is spinning.
I’m debating on setting up an Arduino with addressable RGB lights throughout the car to light up various parts of the car, and have a feature to change light/colors with music. I’ve use a RGB light strip before with a 16×16 pixel light box.
I’m planning on tracing each wire throughout the car to all of the lights and switches, and potentially replacing them this weekend.
I want to have a status light come on when the vehicle is plugged in and charging.
I want to disable the car from moving when charging / plugged in.
I want to be able to disable the car from charging past a specific battery state of charge.
In other news
The majority of this evening was using the hot peppers from my garden to make hot sauce. Enjoy.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
High Voltage Stickers
Created some battery labels to warn about high voltage, and to provide details about the batteries.
Drivers Side Batteries Installed
Re-installing the drivers side painted batteries, main switch, and fuse after lining the battery box with toolbox liner.
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.
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.
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.
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.