Category Archives: Battery

Powertrain Upgrade

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.

Alltrax Troubleshooting

Motor Wires

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


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.

Motor Replacement

Ramps jack up the front quickly

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
CitiCar Motor Replacement


Dragging Wire

Someone warned me that the wires were hanging from the bottom of the CitiCar when I drove up to a car show (that was canceled) on the weekend. They offered a zip-tie, but I thought I had fixed it by pulling up the wires and rearranging the batteries by time they came back with it. Unfortunately, I should have taken them up on their offer. I noticed the wire had been dragging against the pavement. It’s time to get serious on changing over the powertrain.

Wire exposed within 2/0 battery cables from dragging on asphalt

There are a few reasons why this is happening now. The first is that the speedometer cable had been removed, which prevented the wire from going below the motor. However, the latest change was the most impactful. I had installed the motor controller and contact switches. In doing so, I moved the batteries and their wires out of the way so I could get into the area easier. I have the wrong batteries, so there is plenty of room. I think they are moving around while driving, and the motor cables just move along with them.

This is a serious issue. The cables need to be repaired immediately before I drive the car again. It’s questionable on how much of an impact this will have on the amount of amps that the wire can handle now that it’s lost some copper. There is another concern that when driving in parallel, one set of batteries will have less resistance because it has a bigger “pipe” for electrons to flow through.

The new power train is going to be a tight fit, so this will not be a problem afterwards.

Custom Cables

Now that the motor controller and contact switches are installed in the CitiCar, I started moving onto wiring them together. The wires I had were either too short or a bit too long.

I started creating a custom cable. I’m not sure how good my crimp is, so I kept crimping the lug multiple times until the whole length of it seemed to have been crimped. Luckily, I realized that I needed to get some heat shrink before crimping the next lug.

Big tools to crimp big wire terminals
A battery lug that has been crimped one too many times

Teddy and I took the SUV over to the local hardware store tonight. A pack of 5/8″ heat shrink has two tubes that are six inches long. The instructions said to add two inches to the measurement to handle the 4:1 shrinking ratio, so I picked up four packages.

The heat shrink didn’t really shrink that much in terms of length. It seems like I could have gotten away with much less slack. My custom wire looks a bit more professional – to me.

A custom 2/0 battery cable with right-angled terminals and heat-shrink tubing

After the battery cable cooled down, I installed it into the CitiCar to connect the motor negative terminals between the motor controller and the reverse contactor switches.

Custom cable connected to motor controller motor negative (M-) terminal
Custom cable connected to SW202 motor reversing switch motor negative terminal M-
Installing my first cable

Charging Cycle

I got a charge cycle that stopped due to an over-voltage fault. The high voltages at the end of the charging cycles are fairly concerning. After exhausting the CitiCar batteries on a long trip, I kept a fairly close eye on a full charge cycle, recorded the data, and made a few charts:

TimeMin RemainingAmpsAmp-HoursVoltsSoCPhase
9:3479820.9051.020%Phase 1
9:4580320.6451.720%Phase 1
9:5978920.4952.221%Phase 1
10:1377520.21452.723%Phase 1
10:2676220.11853.225%Phase 1
10:3575420.02153.525%Phase 1
10:4574619.82453.826%Phase 1
10:4974019.82654.127%Phase 1
10:5673219.62854.628%Phase 1
11:0272719.43055.029%Phase 1
11:1071919.13255.829%Phase 1
11:1771218.73557.330%Phase 1
11:2435711.93757.473%Phase 2
11:2735510.23757.473%Phase 2
11:312009.03858.289%Phase 3
11:341989.03860.989%Phase 3
11:371949.03964.790%Phase 3
11:411909.03966.190%Phase 3
11:451869.04066.990%Phase 3
11:501829.04167.390%Phase 3
11:541779.04167.690%Phase 3
11:591729.04267.991%Phase 3
12:051679.04368.091%Phase 3
12:091629.04368.091%Phase 3
12:141589.04468.191%Phase 3
12:191529.04568.192%Phase 3
12:24149.04668.192%Phase 3
12:3279.04768.092%Phase 3
12:4000.04855.8100%Not Charging
12:5400.04854.1100%Not Charging
1:0300.04853.9100%Not Charging
1:1000.04853.8100%Not Charging
1:2700.04853.7100%Not Charging
1:3600.04853.6100%Not Charging
2:0400.04853.4100%Not Charging
The state of charge always jumps by 50% in a short period of a few minutes during phase 2
Estimated time remaining is always off by about 400%
Phase 2 appears to be a very abrupt cross-over compared to charging profiles for lead acid batteries around the internet

Over Charging

The charging voltage maxed out at 68.1, each 12 volt battery got up to 17 volts. I hadn’t gone up past 14.5 with regular car chargers in the past. It seems as if the batteries are being overcharged. If they were being equalized/balanced, it would make a bit more sense. This is during the final phase after it reaches 90% charge.

Exaggerated Estimates

The initial estimate was 13 hours and 18 minutes, where the actual charging duration was three hours and six minutes. As the charger progressed through each phase of the cycle, it was getting better, but still highly exaggerated. The device is not learning from its previous charges.

Huge SoC Gains

The state of charge is sometimes abrupt. The state of charge increases gradually until it is at 30% charge at 57.3 volts. Seven minutes later, the battery state of charge jumps to 73% at 57.4 volts. Another seven minutes and we are at 89% charge at 58.2 volts. We then grow gradually up to 92% over an hour, and then jump directly to 100%.

Short Phase 2

Phase 2 is a very short cycle, that is 20 minutes at most. The cross over between dropping amps and increasing reported SoC by 50% is very sharp.

Charger Conclusion

It seems like the Lester Summit Series II charger may be defective or had the wrong battery profile. The CitiCar has four 12v Interstate 31-ECL in series. The battery profile (22001) description seems fine other than the amp hour rating. When I called up the manufacturer, the amp hours (190 RC@25 amps) wasn’t a problem and I was told that the default profile was fine.

  • Single-voltage mode: 48V flooded/wet lead-acid battery packs with a 20-hr rating of 225-260 Ah
  • Auto-voltage mode: 48V, 36V, or 24V flooded/wet lead-acid battery packs with a 20-hr rating of 225-260 Ah
  • Profile parameters: 22A bulk (48V), 25A bulk (36V), 25A bulk (24V), 2.39 VPC absorption, 9A finish, Progressive DV/DT termination, equalize active

I wish the charging status was more descriptive rather than saying “Phase 1”, “Phase 2”, and “Phase 3”. The phases do not convey any information. It would be more useful to see something like Desulfation, Bulk, Absorption, Float, and Equalize.

Capacity Monitor

The capacity monitor arrived. This was one of the last major components of the new system that I had been waiting for. It was fairly simple to setup and I started getting feedback immediately on the amount of amps the CitiCar motor uses when initially starting or going up hills and cruising.

It seems to go around 250 at most, but occasionally has small spikes at 350. Cruising appears to be around 125 amps. I’ll need to put a camera on it while driving to look back later to get a more accurate reading of data.

One special thing of note is that I’m now aware of how much phantom power is being drained. The battery charger and capacity monitor both consume a small amount of amps.

The capacity is not useful for driving at this point because the detected voltage keep swapping between 24 and 48 volts. Once I upgrade the CitiCar to always use 48 volts, the capacity should become useful. However, it does appear to be fairly accurate reporting the same number of amp hours that the battery charger reported.

The capacity monitor is more precise on the number of amp hours supplied by the charger
AiLi Voltmeter in CitiCar

Two aught

I reached out for help regarding battery cables with other d-car owners and enthusiasts. Along with the advice that I got, one of the locals that I met in the CitiCars maiden voyage was willing to help out with supplies and tools leftover from his EV conversion project. Teddy and I hopped into our little car and zipped downtown to the town square.

We met up and with more understanding of the parts of an EV, I was able to have a more knowledgeable conversation this time and had a lot of questions to ask regarding his setup. learning a bit more about how the guy upgraded his pickup truck. I paid more attention to his setup and had my eye on his use of project boxes to keep things segregated, organized and protected. He had quite a bit of advice when I asked about wiring harnesses and thoughts regarding a themed car that could be easily reverted without damaging the body. His thoughts were to look into Plasti Dip and a brand for “Painless wiring” for quality cables/connections where cables are labeled and easy to install.

He had a large box of thick battery cables and two bags of battery lugs. The box was heavier than I had thought and caught me off guard for a moment. Along with the box of cables, I was able to borrow some wire cutters and a gigantic crimping tool. I opened the CitiCars back window and we stuck everything in with plenty of room to spare. Unfortunately, I forgot to grab the wire cutters…

Teddy grows some wings

Teddy and I enjoyed the park and took a stroll down main street. We went through Inklings, posed in front of a mural, and grabbed some ice cream from C & C Frozen Treats. Teddy had some mango while I ordered a quart of brownie ice cream.

Teddy, Lewie, and The Chez CitiCar

By time we left, it looked like a bunch of antique cars were arriving into the town square for a little car show. I had to bail before the rain came. I didn’t make it home in time, and the rain was coming down pretty hard. I kept the wiper on the lowest setting and didn’t run into any problems blowing a fuse this time.

Running 120 volt AC via J1772

The replacement Level 1 & 2 electric vehicle supply equipment (EVSE) arrived today. I verified that it was operational and setup the CitiCar to charge it’s batteries through a J1772 port. I don’t know if the folks at Sebring-Vanguard had ever imagined such a thing, but I am now able to recharge the car at a public charger. Here is the setup in order from the wall to my cars batteries in my little experiment:

  • 120 volt (5-15) outlet in wall
  • Level 1 & 2 EVSE (5-15 & 6-20)
  • EV Charger Power Converter (from J1772 to 120v & 240v)
  • Power strip
  • Five 12 volt battery chargers
  • Four deep cycle batteries for the motor and one small accessory battery
Displaying how I’m charging lead acid batteries with power supplied via J1772

I was loosing a tenth of an amp with the EVSE and power converter. To add more fun to the experiment, I decided to let the car charge to full capacity through the J1772 setup and see how much the total energy is affected.

Cable Inventory

Battery cables

Later in the night I started going through the battery cables I received to get an idea of what I had. The cables can be called either 00, double zero, 2/0 and pronounced as “two aught”.

I started taking inventory, measuring inches from the center hole of each lug.

Cables with flat lugs at each end

Some cables also had a 90 degree lug at one end, but the shorter ones didn’t have a lug at all on the opposite end.

Missing LugTwo Lugs
Cables where one end has a 90 degree lug

Two long cables were included that were 13 feet, eight inches, and another at fourteen feet, 11 inches. The longer cable didn’t have a lug on one of the ends.

There are quite a few good cables that I can use. The longer cables alone may be enough on their own. Many of the smaller pieces can be used for jumps between switches, fuses, controllers, and such.

Battery cable connected to two Chevy Volt battery modules

I found that I could barely use the 10¾” cable to connect two Chevy Volt battery modules next to each other. I have four cables that are 13¾, and four more at 14¼ that I could use with more slack between the batteries. It’s preferable to have a shorter length to reduce voltage drops. Although with the length of this circuit, the drop would already be fairly minimal.

Corroded lug
Wire brushed lug

I spent some time cleaning up one of the most corrosive lugs. I first tried to do it by hand with a wire brush with some progress. I then grabbed my angle grinder with a wire brush attachment and cleaned it up fast. I was finding that I was chasing some of the corrosion down under the heat shrink around the lug.

Things are coming along great. I have many cables that I can clean up and use once the motor arrives. I have the supplies necessary to make my own custom length of cables as well.

Tiny Radio

One of my tiny car radio modules came in the mail today. I actually ordered three different kinds because it was difficult to judge how big they were. This three dollar radio was originally just for a side project to stick on a repurposed 8-track tape. The idea was to give my 8-Track radio some modern features to play music from a blue tooth device as well as micro SD cards.

Bluetooth MP3/WMA decoder USB/Micro SD/Aux FM radio module

I was originally set on installing an 8-Track radio and an Android media entertainment center for navigation in the CitiCar. I’m having a difficult time determining where I should put them. I don’t have much space available on the dashboard to mount things, or the support to mount anything with some weight. I’m considering using one of the little radio modules instead.

I was able to wire the little radio up to work with both five and 12 volts, as advertised. The radio works, Bluetooth hooked up without a problem, and I was able to get MP3 files playing from a micro SD card. One thing of note is that I definitely need an amp. The little radio can put out a signal, but any speaker I try is so low, it is difficult to hear. The voltage supplied to the radio does not make a difference.

Town Square1,138.03.9
RatekWh9.85¢0.46 mph
Total2.21 kWh22.4¢17:00
Per Mile283 Wh2.9¢02:10

Under pressure

External TPMS sensor

The TPMS monitor arrived. The packaging looked like it was opened along the way going through customs.

It was fairly easy to install. Replace tire stem caps with little knobs. An alarm went off almost immediately as I put one on. I changed the units of measurement so the pressure and temperature were set to PSI and Fahrenheit.

TPMS host display

My tires were setting around 20 psi. The maximum pressure for the tires is rated at 51 psi.

I did some quick research and found most cars have a pressure around 32 psi, and that the door should have a sticker with the recommended tire pressure. I only saw the sticker with the VIN on it. I dug through the owners manual and found that Sebring-Vanguard recommended a tire pressure of 32 psi. Inflated the tires to 35 psi.


The recommended tire pressure for standard and radial tires, front and rear is 32 psi. A lower tire pressure will give a softer ride, but a lower speed and ranger a higher tire pressure gives better speed and range.

CitiCar 1976½ Owners Manual, Sebring-Vanguard page 24

Power Transmission

Along with receiving the majority of parts by the end of next week, I’ve been researching battery cables. The first thing was to identify the amps going through everything.

Battery Monitor350500
4 Battery Modules4 * 250
4 * 400
Battery Switch350
600@5 min
1200@30 sec
Contact Solenoid650650
Motor Controller380
420@5 min
500@2 min
Reversing Contactor400400
Max Amps Allowed350400
Amperage that devices can produce, handle, or draw in the circuit

The fuse does not allow any more than 400 amps supplying the motor. From here, I was able to get a general idea of how large the battery cables need to be.

In addition to amps, I also had to take voltage drop into consideration. To do this, you need to know the length of the full path in circuit – battery to motor, and back again. I took some string and laid it out in a large loop around the bench seat. It came out to roughly nine feet.

The parameters are 48 volts @ 400 amps running along nine feet of cable. I found a calculator and put in the following:

Gauge2/0 AWG
00 AWG
Voltage48 VDC
1-way circuit length4.5 feet
Load400 amps
0.288 VDCVoltage Drop
47.712 VDCVoltage at Load
0.6%Voltage Drop
circular mils
Wire cross section

It appears 2/0 AWG wire will handle the maximum load the fuse will allow with a minimal voltage drop.

In other resources, I’m finding that 00 gauge is often rated for a maximum current of 186 amps, and that you should never exceed 80% of the rating (148.8 amps). Even a 4/0 wire will only be rated for 380 amps max.

In this scenario, it feels like the wire will melt before the fuse breaks. Things that confuse me are that the information that I’m finding is often for bringing electric into a house. I often look at how golf carts are wired up, but they are often working with 2 AWG wire, which is much smaller than 2/0 AWG.

To support 400 amps, I think I would need 500 kcml / 500 mcm of copper wire rated for 90°C. It looks like it costs roughly $14/foot. The wire is thick – as in power lines on telephone poles. I wouldn’t have the ability to afford tools to cut, crimp, and bend the stuff. Besides speed, I think modern EV’s go with higher voltage systems to reduce the amps needed, thus reducing the size of the wire.

The motor controller supports current limiting, so I could force it to use no more than 148.8 amps if I desired.

Someone local that I met on the maiden voyage has a few tools and supplies to help out with that they had used on their own EV.

In other news

  • D & D Motor Systems is shipping my motor.
  • Popular Science, June 1975 has been shipped
  • The portable EVSE has been shipped
  • I need to do some research on plug breaking / dynamic braking
  • I may need to contact D & D Motor Systems or Alltrax to see if they have a field map for my specific motor / controller.

Tapping The Nut

It seems like I’ve been constantly getting nowhere with replacing the battery terminal nut. Everything I’ve purchased for battery terminals has been too small. I have a variety of nuts on order, but they won’t be here for a few days.

Tapping a nut

While cleaning up the garage over the weekend, I came across a little 24 piece tap and die set. I considered that maybe I had stripped the threading in the nut, and decided to try tapping it. I could get the CitiCar back on the road quicker, and the nut was already useless at this point.

I grabbed a little table vice to hold the nut in place, and opened up the tap and die set. I rolled my eyes as soon as I realized the set was in metric. I probably got this when I was building the Tricolour RepRapPro 3D printer based on plans from the UK. I may eventually end up buying a larger set that also includes both metric and SAE.

I first tried a 9 milometer tap. I could feel the bite as I slowly bit through the metal. Once I was able to freely spin the tap, I tried putting the bolt on the terminal.

Unfortunately, I came up with the same results as every other attempt over the past few days. Too small. I went ahead and tried the 10 millimetre tap. It was much harder, but … success! The bolt slid on the battery terminal just fine. I was able to connect all of the battery cables.

I went ahead and charged all the batteries for our next adventure in the CitiCar. In the meantime, I started looking at how to hook up the EVSE with a transformer that could connect to a public charger and convert the power to 120 volts. From here, the plan was to connect my five individual battery chargers.

EVSE fault

I was quickly blocked as soon as I plugged the EVSE into an outlet. The charger was blinking to indicate that it was protecting from a low/high voltage. I checked that the circuit was wired correctly. I also verified the voltage was in range at 124 volts. I tried outlets around the house on other circuits. I even plugged it into the back of my computers APS power supply to ensure a clean cycle of power.

Chevy Volt battery module cut on side

I cut the bottom edge off of another Chevy volt battery module. Although I had a hiccup with the EVSE, a few things are progressing fairly well today.

I think Teddy and I will be able to visit the park and grab some Ice Cream tomorrow.


EVSE Problems

Other News

Some button cell batteries arrived. I was able to fix Teddy’s talking ball. I replaced the battery in my calipers, but the digital readout wouldn’t turn on. I took a closer look and found that one of the contacts looked as if it would touch both the positive and negative parts of the battery. It looked like it was bent down and curved a little. I thought it was a spring when I first saw it. I flipped it up on its side. It matched the curve of the battery and… it broke off.

I remember it was only a few bucks. It still works manually. Perhaps I should invest in something with more quality the next time I go looking for one.


Irwin Industrial Tools 26313 Metric Tap and Hex Die Set, 24-Piece
Megear Level 1-2 EV Charger(100-240V,16A) Portable EVSE Home Electric Vehicle Charging Station Compatible with Chevy Volt, Nissan Leaf, Fiat, Ford Fusion (NEMA6-20 with Adapter for NEMA5-15)
EV Charger Power Converter
4A Fully Automatic Microprocessor Controlled Battery Charger/Maintainer
NEW Lithium Ion Chevy Volt 48vdc 2kwh 50ah battery Golf Cart Off Grid Solar EV
DEAL INDUSTRIES INC. 61-501 Receptacle Tester with GFCI, Black
WEN 423DPV 3-Inch Cast Iron Drill Press Vise
Winkeyes 0-6 Inch Digital Vernier Caliper with Inch/MM Conversion Large LCD Screen and Stainless Steel Body Vernier Caliper Tool for Small DIY and Homework, Coin Battery included, 150mm
Pet Qwerks Talking Babble Ball Interactive Pet Toy – Wisecracks & Makes Funny Sounds, Electronic Ball that Talks & Makes Noises – Avoids Boredom & Keeps Your Dog Active
LOOPACELL AG13 LR44 L1154 357 76A A76 Button Cell Battery 10 Pack
RepRapPro Tricolour
Things I’ve purchased, or very close to it.

Battery Fitness

Cardboard cutouts of Chevy Volt battery modules.

With all of the projects on the CitiCar, one of the most important ones is to upgrade the batteries to Lithium. I found some Lithium Ion Chevy Volt batteries. I took the measurements, made some cardboard cutouts, and tried to plan out where the batteries could sit. I just barely could not fit two on each side. I was hoping that maybe the measurements were off.

I took delivery of two lithium batteries a couple weeks ago. Each module was configured to deliver 48 volts at 50 amp hours, for a capacity of 2 kWh. I spent some time placing the battery modules in different positions in the CitiCars’ battery tray to determine if I could fit more than two batteries under the seats for more range and less demand on each battery.

Chevy Volt battery module on lip at edge of CitiCar battery tray

It wasn’t exactly perfect, but I saw a way to make them fit. I went ahead and ordered two more batteries. I could almost fit a fifth one, but it was simply too tight for my comfort, and I could use the space for other things such as a motor controller, DC-to-DC converter, and possibly the charge controller as well.

Dremel cutting edge of battery module

Tonight I started out trying to cut the bottom flange of the batteries where the batteries coolant had passed through. I watched a few videos on people tearing down the batteries to get an idea where I could cut without coming close to the Li-Ion cells. I got out my rotary tool and went to town.

It quickly turned into a challenge. The layers to cut through are composed of plastic, rubber gaskets, coolant plates, and coolant still remaining within. The smell was pretty awful as well.

Cutting battery module with a hack saw

The rotary tool was having a tough time and was getting too hot to handle. I started using some metal shears and a wrench to chip away a little and strong arm it a bit. I wasn’t getting anywhere fast. In the end, I used a hacksaw.

Battery module on its side with side of coolant tunnel cut off

The hacksaw was quick and clean. Rather than having black rubber melted on everything, I could see the profile of the rubber gaskets and cooling plates against the plastic and air pockets.

It took a bit longer to finish off the bottom cut since it was thicker, and cut into an unused brass threading. I believe it was originally used to both keep the batteries together, and keep the water intake bolted onto the battery. Looking back at the

Chevy Volt battery with bottom right coolant tunnel cut off

Other News

In other news, my 10mm Hex/Allen wrench came in today. It was too big to insert into the axles fill plug. Going down, 9mm is a non standard size. I purchased a set that contained contained a wide range of sizes in both metric and SAE with balls on the end of the arms. The SAE set includes 3/8″ and 5/16″, to which I hope one will fit. It’s also got a set of star wrenches, but I’ve rarely had a use for them in the past.

Some nuts for the battery terminals should arrive tomorrow, allowing me to drive the car again.

I ordered some magazines with articles about CitiCar/Comuta-Car:

  • Consumer Reports October 1976
  • Hemmings Classic Car September 2018
  • Car and Driver March 1994
  • New York Magazine May 21, 1979
  • Popular Mechanics July 1974
  • Golf Car Options Magazine January 2018


Making a battery fit into a CitiCar
Fitting lithium batteries into the CitiCar


These are the products I’ve purchased that are mentioned.

NEW Lithium Ion Chevy Volt 48vdc 2kwh 50ah battery Golf Cart Off Grid Solar EV
Dremel 4300-5/40 High Performance Rotary Tool Kit with LED Light- 5 Attachments & 40 Accessories- Engraver, Sander, and Polisher- Perfect for Grinding, Cutting, Wood Carving, Sanding, and Engraving
Stanley Hacksaw 24 Tpi 12 “
Columbian By Wilton Aviation Snip Set 3pc. 30676 Straight, Right, Left
Consumer Reports October 1976
Hemmings Classic Car September 2018
Car and Driver March 1994
New York May 21, 1979
Golf Car Options Magazine – January 2018
Popular Mechanics July 1974
REXBETI Hex Key Allen Wrench Set, SAE Metric Star Long Arm Ball End Hex Key Set Tools, Industrial Grade Allen Wrench Set, S2 Steel

The Egg Before The Chicken

I’ve had quite a bit of fun driving the CitiCar. I want to go further, and a little faster up hills. The main drawback on range is that the battery capacity in my car is very low. I could upgrade to a proper set of batteries to match the manufacturers recommendation, but I would be shelling out one to two thousand dollars based on quality and composition. However, if I am going to upgrade the motor as well, I should wait on the batteries until I’ve chosen a motor, as it may need a different voltage. Both options are costly, and doing both doesn’t seem to make sense. If I go for the batteries, there is a chance I will not upgrade the motor unless it fails, and then the battery voltage of what I already have will heavily dictate what motor I will get.