THIRD TIMES A CHARM???

This is the third Better Place Module that I have had the privilege to bottom balance and must admit, after seeing the aftermath of the fire at EVTV, am being a bit more cautious. When bottom balancing the Better Place Modules, they are always on  a furniture dolly, so they can be quickly wheeled out into the driveway should anything go wrong.

As I described in my last post, the process is started by finding the lowest cell and then hooking up two 1000 watt halogen flood lights and bringing them down until the lowest cell is 2.9 volts. The lights are then disconnected and another voltage reading pass is taken to make sure that is still the lowest cell. The volt meter is then moved to the new lowest cell or left as is, if that is still the lowest cell. Then a 40 watt light bulb is used to draw the cell voltage down to 2.75 volts. Once the cell is down to 2.75 the light bulb is turned off and another voltage pass is taken to make sure that is still the lowest cell. Then a 5 watt light bulb is connected to the module and left on until the lowest cell comes back down to 2.75. This is the stage I am currently in, as once the 5 watt bulb is connected, the voltage starts coming  back up and often goes close  to 3 volts before it starts coming down again. I started this yesterday morning and after 25 hours of discharging, still do not have the low cell stabilized to 2.75 volts.

When the cells are drained, they seem to always drift back up but when they are charged seem to always drift back down in voltage, so once I get the low cell down stabilized at  2.75 volts, I start charging them all back up to 2.8 volts or what ever voltage the highest half cell is resting at. Remember, the Better Place cells are LiMn2O4,  not LiFePo4 cells and operate at a higher voltage range, so when they are down to 3 volts per half cell, are pretty much depleted. My controller is set to cut off at 90 volts or around 2.8 volts per cell, so the module should never discharge lower that that.

While the module is being discharged, a post it note is stuck to my laptop to remind me and I check the module every half hour or so. I have found that since the LiMn2O4 cells are so "bouncy," the best way to get them to stabilize below 3 volts is to discharge at a very low level when approaching the desired low voltage.

Also, measurements were taken in the nose of the Fiero and the module will fit, so am thinking about how to mount it. To get the module in from the top, the hood will need to be removed but this may be the best way to install it.

Until next post,

Randy

BOTTOM BALANCING THE LAST BETTER PLACE MODULE

We have had a few nice weekends in the last half of February, so decided to start bottom balancing the third Better Place battery module. 

The terminals and connectors were  all cleaned with scotch bright and a thin coat of Noalox anti-oxidant compound was applied to the them. The connectors were positioned on the terminals and a small drop of Loctite was applied to each of them before threading them into the terminal. A socket on a Dewalt drill with the torque setting on 3 was used to tighten all of the terminals.  

Then voltages were taken on each half cell and most of them were in the 3.85 volt range but one cell was only 3.65, so the volt meter was hooked on that half cell to monitor the drain down of the module.

Eye terminal connectors had been previously crimped onto the end of an extension cord and two 1000 watt flood lights are used to draw down the module. When the voltage reading on the lowest cell approached 3 volts, the individual half cell readings will be taken again and a different cell will be monitored if necessary. I will drain the module down to 88 volts or 2.75 volts/half cell and let the module set for awhile, as it will drift back up in voltage in a few hours. Then a 100 watt light bulb is hooked up to allow the voltage to be drawn down slowly. Finally a 5 watt night light is hooked up that allows the voltage to be drawn down even more slowly. This is the only way I have found that will cause the voltage to finally stabilize and not keep drifting back up. Even after that, over a couple of weeks, the cells will drift back up to around 3 volts. 

After the initial draw down and couple of weeks sitting, individual half cell balancing is done with a JLD404 and a 4 volt flashlight bulb. The JLD404 is set so it drains the half cell down to 2.75 volts and does not turn back on until the cell drifts back up to 2.95 or so. These are just hooked up and allowed to cycle until the half cell stabilizes under  2.95 volts.

BOTTOM BALANCING MODULE

With spring just around the corner, I want to get a running start to get the Fiero back on the road with all three modules installed.

Thanks for visiting,

Randy

TOPPING OF THE PACK

While lithium batteries really don't self discharge much, the pack had not been charged since last year and the Fiero had been driven down the road and moved around the driveway a couple times, so with the temperature close to 70 on Saturday, I decided to hook up the JLD404 and top off the pack. The first thing I noticed is the JLD404 in the car was reading higher than the EPM-5740TV volt meter in the engine compartment, so I will have to get out a voltmeter and calibrate them. The module catching on fire at EVTV has heightened my awareness to the possibility of the modules lighting up, so want to make sure I have a good back-up system to discontinue the charge.

The amp meter on the dual volt/amp meter reads when the motor is revved up but is very erratic and seems to be out of sync with the amp reading on the JLD404. The wires are twisted coming from the shunt but it acts like it is getting interference form somewhere.

Not much work was actually done but it was good getting out and messing with the car.

Until next time,

Randy

PARTING WITH MY MIATA

A hundred thousand miles ago, I purchased a 1989 Miata with 75,000 miles on it from EBAY. After a flight to Philadelphia, and a puddle jumper to Allentown, PA, I was on my way back to Ohio. After driving a few miles I noticed a strong smell in the car and as the previous owner had recently passed, wondered if it wasn't in the car. Half way home the clutch quit working but was able to put in some more fluid and make it home.

Turned out the fender drains were plugged and water from the convertible top drains into the fender wells then exits through the drains. The slave cylinder on the clutch had to be replaced but after that, the car was great. You normally drive down a road in the summer with the air on but in the convertible, you could smell freshly cut grass and the sweet smell of wild flowers.

When EVTV had their Build Contest before the first EVCCON, my entry was the Miata, using rear drive, single speed transaxle, AC motor. I didn't win but did drive the Miata to Cape Girardeau for the first four years. The car was just sitting in the driveway and had an overheating problem that I just couldn't seem to isolate. Then the window regulator broke and the drivers side window would not go down. Instead of letting it sit in the driveway and pay insurance on it, just seemed that selling it was the right thing to do, so it was listed on Craigslist.

I received several inquiries but finally got one from a guy in my area who wanted to come and look at it on the weekend. We have been experiencing some of the coldest weather the last several days, so when I went out Saturday morning to get the car running, I had problems getting the trunk open to try and charge the battery. Ok, finally got it open and hooked up the charger, so several hours later, had the same problem getting the door open to try and start the car. Finally when in the car, nothing! The battery was removed and taken back to Autozone where I had purchased it and after fumbling around with it for a few minutes, the salesman said "Yep, she's toast!" Fortunately, it was still under warranty, so walked out with a brand new battery. Once the battery was in the car turned over smoothly and started, for about two seconds, then just puttered. Ok, it was cold out and car had not been started in months, so decided to put a heat gun under the hood to try and warm the engine up a little. No surprise, the hood would not open, so after cleaning as much snow and ice off of the hood as was possible, was finally able to pry it open and get the heat gun under the hood. After going inside to get warm for about a half hour, I tried to start the car again. This time it started for about 30 seconds, then puttered out. After a couple of tries, the engine finally kept running and after idling about 15 minutes, took it down the road for my last drive. Upon returning, I pulled it in the garage and by the time the potential buyer got here, had most of the snow and ice off of the car.

After the usually tire kicking and dickering back and fourth on a price, we came to agreement and the Miata was gone.

1989 MIATA

So long to the Silver Bullet!

Randy

MORE ZOMBIE 222

I have been following Mitch Medford's quest to break 200 mph at the Texas Mile and ran across his new YouTube series on installing new Voltbox battery modules. The modules use A123 Lithium Iron Phosphate battery cells and are rated at .98KW/module.

TECHNICAL SPECIFICATIONS:

Standard energy module

Rated voltage: 12.8V

Capacity: 0.98kWh

Weight: 10.4kg

Dimensions (inch): LxWxH: 

approx. 11,1 x 3,5 x 10,16

Good luck to Mitch in his quest to break 200 mph!

Randy

GORGEOUS DAYS!

Here we are on the seventh of February and the weather over the weekend has been spring like, here in central Ohio but no work was done on the Fiero. The new rubber wheel well splash shields from the Fiero Store arrived a couple weeks ago but just didn't have the motivation to put them in yet. I did move the car to do a little paint work on the Mercedes SLK 230 headliner trim pieces but that is about the extent of messing with it.

Even though my posts have been down, the hits on the blog were up in January and are already at 106 views for February. Thanks to all of you who have been following this build and I promise, the posts will pick up in March.

Currently, new equipment is being gathered to be able to do some drive videos and I am really shooting for getting the third module installed so the car can be driven the 22 miles to work. Several of my co-workers have been interested in seeing the conversion but I want the car to be working and look as good as possible before showing it. Hopefully by early spring it will be ready for prime time!

Inside EVs ran an article titled "President Obama Proposes $10 Per Barrel Tax On Oil In Push For Cleaner Transport" and it is ironic because if any of you follow EVTV, Jack Rickard laid out a very similar plan to tax gasoline, starting with $.25/gallon and gradually raising it over the next 5 years. Now I am not advocating raising taxes and the chances of passing a bill to raise taxes on oil would be slim to none, but it would be a way to fund clean transportation and give additional incentives  for the public to try an alternate fuel vehicle. 

Well, got my EV fix out of the way for this week, so back to the Superbowl. Thanks for visiting and don't forget to leave a comment.

Randy

HOW TO BECOME A PART OF RIMAC AUTOMOBILI

Looks pretty exciting!