Early Voting

Today is Tesla battery investor day. A vacation day was in order. A quick trip to the registrar for some early voting was followed with a relaxing vacation day with Teddy.

Gertrude, as with most trips, was first on our list of destinations. Teddy slowly made his way around the park. We hung out on the side of happy creek by the wooden overlook. Small fish were swimming about, and Teddy found an old mangled baseball in the creek.

We were soon on our way over to KFC. I made sure to ask for a cup holder since the CitiCar doesn’t have a place to hold drinks.

One of the great things about a CitiCar is that you can back into a space half-way, and have quite a bit of room to sit on the curb and lay out your meal on the ground behind the car. In Teddy’s case, I’m able to put a cup of water and some ice cubes on a lid that he can’t knock over and spill.

The next stop was at B&L Custard. The owner asked us where our little red car was. I pointed, but a larger car was obstructing her view. Teddy had his usual “Pup Cup” and got a bit messy with it. I had a strawberry shortcake sundae in a waffle bowl.

Next on our little trip was a visit to Bowman park. It’s a small park that I rarely visit, and we hadn’t driven to the the park with the CitiCar yet. A few picnic tables and benches are scattered throughout about an acre of land on a gradual incline. The park has very old and thick trees. Acorns were falling fairly often, but I didn’t see any squirrels.

Laying against a tree for awhile, I had started to lose track of time until the church bell rang at half past four. It was time to be on our way back home.

New Charger

The Lester Summit Series II charger arrived while we were out on our little trip through town. I plugged the car into the regular battery chargers and started to look over the instructions for the new charger, attaching wires and screwing the cover on. Tesla Battery Investor Day started while I was going over the details and I had a live stream playing while I continued to work on the charger.

The ring terminals that came with the charger were too small for the battery terminals that came in the CitiCar. I created a pair of wires with ring terminals large enough to connect to the battery terminals and connected them to bus bar terminals. The charger powered up and I was able to connect to it via Bluetooth.

The default battery profile was for 22001. It wasn’t all that descriptive. I went to the battery profile selector, choose battery manufacturer as “Interstate”. After being unable to find my battery model number, the app told me to contact Lester Electrical by phone. The office was closed. I left a message with technical support.

I looked into what 22001 was about. The profile information said it was for a 48v flooded/wet lead-acid battery pack with a 20-hour rating of 225-260 Ah. I don’t know what effect amp hour capacity has on the charging process. I didn’t know what kind of Amp Hours my batteries had.

Brand	Interstate
Model	31-ECL
Reserve Capacity (RC)	190 @ 25 amps
Guessing: 190 minutes / 60 minutes	3.166 hours @ 25 amps
Guessing: 3.166 hours * 25 amps	79.166 Amp Hours
Final Answer…	79 Amp Hours

I decided to give the default setting a go. I immediately noticed a difference in the amount of watts used to charge the battery. When using the five individual battery chargers in the past, they used a combined wattage of about 333 watts. The charger was using 1165!

The CitiCar batteries were charging up fairly quickly. It was great being able to see the current state of charge, phase, and predicted time for the charging process to complete. With the other chargers, I would have been waiting 11 hours to recharge at a rate of 0.8 miles per hour,

Towards the end of the charging cycle, I noticed that the voltage was fairly high for charging batteries at 64.1 volts (16.0 volts per battery). In the past, my other chargers would only go up to 14.5 volts on an individual battery. I went to check on the car and it sounded like the batteries were boiling. I opened the garage door as a precautionary measure to ventilate. I didn’t smell anything, but I wanted to be safe. I reached out to other C-Car owners. One confirmed that they had this issue as well and were told the batteries were okay.

The last phase seemed to drop the estimate drastically, stating 13 minutes, but was off by almost two hours. I thought maybe the temperature drop outside was having an effect on the chargers thoughts on how much the voltage needed to increase as the weather got colder. At least I now know that my batteries can hold 50 amp hours.

Time	Remaining	Amps	AH	Volts	SoC
6:52	727	20.5	1	51.9	29%
7:03	533	20.4	4	52.3	60%
7:34	505	19.8	14	53.9	63%
7:44	495	19.6	17	54.6	64%
8:33	191	9.0	29	64.1	90%
9:06	13	9.0	34	64.7	92%
9:35	3	9.0	39	64.9	93%
9:39	3	9.0	39	64.8	93%
9:47	2	9.0	40	64.9	94%
10:55	0	0	50	54.4	100%

The end result was a charge that would normally take 11 hours was done in five and a half. I was charging at 1.63 miles per hour! Unfortunately it looks like the quick charge rate also increases the watt hours per mile. I’m often averaging around 280 watt hours, but the recharge from this trip was 391 watt hours per mile.

Due to the quick charge rate, I could potentially take two trips in the CitiCar per day. I could take off with Teddy to the dog park in the mornings and go for a second ride in the evenings.

One thing to consider is that the batteries were being charged for a little over an hour on the old chargers before switching over. I may have been able to shave an hour off of the charge time if they started out on this charger from the beginning. The results from the next trip may give a better baseline of what to expect in future charge times and costs.

I’m hoping that the over-charge voltage was a one-time conditioning of some kind. I don’t like the idea of degrading the batteries from overcharging. When looking at the logs, I suspect that this will happen every time. I’m hoping that it will consider the time from prior charges to improve the accuracy of estimated time remaining on a charge.

If everything works out well, and there is a profile for the Chevy Volt batteries, I’d like to use this charger for the lithium ion batteries as well since it has quite a lot of features through its app, and it also has extra wires to give it the ability to prevent the car from going anywhere when connected to AC power.

After the batteries were charged to 100%, the charger wasn’t registering any power on the Kill a watt meter at all. Not even a watt. It’s powered by the battery pack alone. The other chargers that I had would always draw about two watts each after the batteries were fully charged – adding to the overall cost of maintaining the battery pack that that I don’t record in my logs. They would also draw more power every now and then in the “float” phase to maintain the battery voltage over time.

In Other News

Battery investor day went well. I just wish I could get ahold of some of those new batteries for the CitiCar. It’s an interesting concept to use the batteries as structural support as part of the frame. The whole car frame of the CitiCar is already used as ground. I went ahead and put in an order for another $500 of TSLA shares in the morning.

The speedometer has trouble getting a GPS signal sometimes, resulting in unaccounted miles if I take off before it acquires its position. In addition, the speedometer does not report speed until it has a signal. The sky was clear today and I would be waiting for a minute or two waiting for the timer to catch the signal.