[914EV]

Hi Everyone,
No one has responded yet to my query but some have at least looked at it. I continued to research this issue on the forum site and have answered my immediate question. So I will briefly summarize what I have found and cite where the information comes from within the forum discussions. I have not found a summary of the TC/Elcon TCCH battery charger start up sequence anywhere else in the forum so will document what I now know here.

The TC/Elcon battery chargers are much more sophisticated than I first realized. The firmware coding is setup to provide correct voltages and currents through the charge algorithm for a particular battery pack and its chemistry. But in addition, the firmware also has some built-in test (BIT) and safe guard functions as well.

At power up, the DC side of the charger does not immediately power up but retains signal capability essentially seeking electrical information about the batteries. There are at least two electrical parameters it is looking for (and perhaps more). First, is the polarity correct? And second, the charger appears to be seeking the correct voltage range of the battery it is designed to charge. Both of these conditions are implied by Reedb during his description of attempting to measure the DC voltage while experimenting with the CAN bus on his charger. The description by Reedb is located at this link.
TCCH Elcon charger troubleshooting and repair

The polarity check and subsequent engagement of the DC power-up relay is confirmed by Coulomb at this link.
Elcon 1500w charger problem

The charger seeking the correct voltage range is confirmed by dtBaker in his response to Reedb. The dtBaker reply is at this link.
TCCH Elcon charger troubleshooting and repair

In his reply, dtbaker essentially states that the charger requires a battery pack to perform a final test. I took this to mean that there were limiting ways to measure the output voltage of the charger if the battery pack wasn’t available (dang it!).

The discussion between Reedb and dtbaker is helpful. In my situation, I changed battery pack selection after purchasing my charger and the battery voltage no longer meets the charger parameters. I am now trying to determine if the charger I have can be reprogrammed per the startup sequence where a momentary test button is held for a period a time in seconds that corresponds to and shifts the voltage output in the firmware. My charger has no label describing extra voltages but the description is discussed by Coulomb along with an obsolescence notice which also covers the age of my charger at this link.
Elcon/TC Charger Firmware: Facts

And kennybobby lists the TC Elcon TCCH Charger master link thread at this link.
TC Elcon TCCH Charger master link thread

-914EV

 

[914EV]

Hi Bob,
Thanks for responding and sharing your experience. I did reach out to Elcon a few days ago. They quoted reprogramming the charger (going from 105V to 98.4V) at $130 plus return shipping. Shipping from here is about $40 one way. The voltage is for charging a Chevy Volt set of batteries (24 cells, 96V nominal). Now just trading off whether to reprogram or sell this charger and purchase a newer version. Thanks for the encouragement.
Bill

 

[914EV]

That's a really good reasoning. I keep reminding myself that this is a platform and that the drive can be changed over time. Getting the charger problem resolved checks that box as well and then I can get the motor, inverter, etc. bench tested and installed. Will continue posting here about the charger progress as I send it for reprogramming.

 

[914EV]

Hi PDove, Thank you for responding. A peculiar thing about my charger is that it does not have the white label as described by you and others in the forum detailing alternative charging voltages. Attached is the label describing its workings.
Here is a description of how I proceeded to bench test the charger. Attached a 120VAC plug to the input cable. Screwed down the output cable terminals about 3" apart on a board and then clamped the board to the test bench. Jumpered Pin 1 to Pin 3 on the 7 pin connector. With everything cleared on the test bench and a DVOM handy, the charger is plugged in. The red/green LEDs flash as normal indication that the charger is not attached to batteries. There is no measurable voltage at the output terminals. Power down.
I would love to know how to read the data off of the 7 pin connector. There is a mating connector for this on order but my test leads can safely reach into the connector sockets. I am hoping that like labeled chargers, this one has a variety of voltages available around its 105V setting.
I changed to 4 Chevy Volt 24 Cell, 96 volt batteries to be wired in parallel. The upper cell voltage for these is 4.15 volts and after more thought, I would like the charger to produce 99 volts which would provide 4.125 V/cell. 2 packs are forward and 2 are aft with the charger being located forward.
That is about it in a nutshell. Thank you for any assistance for this problem.
-914EV

 

[914EV]

Very good. It didn't occur to me to break open the pack and jumper cells. Great idea. That will get things turned on and then testing whether or not there are any programmed voltages around the 105V. I am traveling over the next few days but can attempt this on Thursday.
Keep in mind that the offer still stands from Elcon to do the reprogramming.
How much trouble/work is it to build the monitor/hex decoder? This device seems sought of important to monitor the batteries during charge. I don't yet have a BMS for this project.
Thanks again for the help and suggestions.
-914EV

 

[914EV]

I have hardware experience (simple shield card design) with the Arduino controller card but have limited coding skills. Let me know what if anything I can do to help.
I'll post some data late on Thursday regarding the power up and voltage output experiments.

 

[914EV]

Pdove,
Today I took the top off of one the Volt packs, made a couple of jumpers and connected two of the packs and the charger (see picture). Positioning jumpers to different cell counts was a really great way of performing this initial testing. Safety note: Right after I took this picture I covered the exposed top of the battery pack with a plastic tote box lid in the remote chance that something metallic got dropped onto it.
Given the current SOC, here are what the cell combinations measured.
25 cells = 101.1V
26 cells = 105.0V
27 cells = 109 V
With pins 1 and 3 connected and a count connection of 26 cells, the charger was plugged in. Within about 8-10 seconds I could hear the output relay click and the LED indicator flashed red in 1 second intervals indicating <80% charge. The voltage across the packs was 105.1V. I let it charge for about two minutes getting a sense that there was a slight increase in overall voltage.
I then turned the power off and experimented with hooking to the other two combinations. With the 25 cell count, the charger again indicated <80% charge and I let this charge for about 3 minutes. The black jumper being a smaller gauge wire started to feel warm to the touch. I powered down and then selected the 27 cell count. The charger recognized a battery connection, turned on the output relay, but within about 30 seconds it switched the output relay off and the LED indicator was one of battery disconnected.
Now having a better idea of how the charger was operating, the charger was powered up again with the 26 cell count. The LED indicator communicated <80% charge and so I let it charge for about 5 minutes. After about 4 minutes the LED changed to yellow flashing (>80% charge) and within about a couple of more minutes of that change, the green flashing LED lighted (100% charge). The charged 26 cells measured 105.2V. I don't trust the accuracy of the digital meters I was using and settled on using just one. I suspect that these are accurate within 0.2-0.3 volts but have no way of calibrating them. The 105.2V measurement was performed on a 200V scale.

I have read through the suggested forum topics and am gathering the components to build the RS-232 interface. Most of the discrete components I have and ordered the DB9 and a USB to serial adapter. And I will start learning how to connect and operate the COM port through my laptop.

Very delighted with the results today. Looking forward to having the RS-232 information available to then address the charger's programming.

-914EV

 

[914EV]

Just a brief update on my quest to get the Elcon Battery charger to the voltage the battery packs need. I went through the exercise of leaving the internal momentary switch pushed while turning on the charger. As taught by others in this forum, this enabled me to reprogram the algorithm and then bring it back to the initial algorithm, this is for output voltage only. Since I do not yet have the RS-232 adapter setup, I don't know what the output voltages are except the original one.
I am awaiting the DB9 connector to assemble discrete components within it and start connecting to my laptop. So far I have gathered parts, the how-to information, and downloaded a terminal app (RealTerm). The DB9 is to be delivered tomorrow. The result of all of this is to determine whether I can simply use the push button to set the voltage or send the assembly to Pdove for updates.
-914EV

 

[914EV]

In my first tests, I let the charger go until it stopped and posted that voltage which closely agrees with the maximum labeled charge voltage. In scouring the forum for as complete an understanding of this TC Charger, I only saw that the charger’s possible alternative programming was for voltage variations. You have now introduced another possible function as to what the charger manufacturer could/might have produced. If I use the 26 cell count as a test bed and switch sequentially through the ten programs, the experiments may show an increase in voltage or increase in charging current (adding an ammeter into the circuit). I can only show a decrease in voltage by lowering the cell count but that scenario has limitations due to not-to-exceed cell voltages.

In the next set of experiments, I need to determine what changes when using the push button to change the charging regimen. I have available 96 cells (4 packs x 24 cells), voltmeter, ammeter, and possibly an RS-232 channel which can provide some of the charger’s parameters. Each cell is now charged to around 4 to 4.04 volts. These cannot exceed 4.15 volts for their chemistry (Chevy Volt battery chemistry).

The setup is a battery charger connected to a predetermined number of battery cells. These cells have a summed voltage now very close to or exactly at the battery charger design output. The charger will not output a voltage disconnected from the battery. With the charger connected to the battery, the battery charge is going to be either close to or exactly at the charge voltage for the predetermined number of cells. I won’t be able to measure the charger’s true output voltage while connected to the battery until it nears the completion of its cycle. (I have copies of some Elcon Charger algorithm curves and the charge voltage varies depending on the SOC). If I increase the cell count and change the program, I can go to a higher voltage if the charger allows. But if the voltage remains at 105V, I can’t go down in cell count and operate the charger until it completes the cycle without overcharging the cells. My understanding of the RS-232 output was that the output voltage would be communicated without need for the output relay engaged. So my strategy was to get the RS-232 communication functioning and then go through each program sequentially to see what the output voltages are.

Let’s assume that the ten charging regimens are set at 105V but different capacities. Using the 26 cell count as the test bed, I can set the charger on each regimen and charge until it stops while measuring voltage and current. This would prove that each regimen is at 105 V and possibly provide some indication of charge capacity to each regimen through the current reading. This set of experiments wouldn’t take that long to perform while I am still awaiting parts for the RS-232 connection.

 

[914EV]

Thank you as I continue to learn about the charger. I looked again at your earlier post and must have mentally pocketed the suggestion of the single voltage. Perhaps wishful thinking that there would be other voltages in the package with the possible reprogramming on this end from the push button. I will have more data to post tomorrow. We’re getting pre-winter weather today which requires distracting chores.

On the communication port, the remainder of the parts came today including the 7 pin mating connector from back east. Consider me forewarned regarding that the port can be blown out and I think Coulomb relates this on his posting of the schematic. I will pay careful attention to ringing out the circuit before powering up and paying attention to the grounding.
From the forum description, it looks like the com port voltages are unusual relative to RS-232 standard and which I take is the purpose of the circuit on the sub D9. I will likely have more questions about interpreting the serial data being streamed.

 

[914EV]

I was able to run more experiments today in attempting to characterize how the charger is programmed. The results and observations from today lead me to an initial conclusion that the all ten algorithms are likely the same. As described earlier, the battery pack limits how the tests can be conducted, but the test results of each iteration are so identical it’s hard to imagine a different outcome.

See attached notebook page.

During the second iteration there is some current being drawn in the 26 cell (105 V) test (2.3 amps) for a short period. This quickly goes to zero as the 26 cells reach the 105.2 V maximum of the charger. In the next eight tests using 26 cells, there is no current being drawn as the cells are fully charged. I don’t know what caused the first iteration to measure zero and then have a current draw immediately on the second test but then return to zero on the next 8 tests. However, it was observed that at the start of each test, the charger would start out at <80% capacity. The red LED indicator would flash 11 times, change to a yellow LED indicator, flash 11 times, and then change to a steady green LED communicating a full charge. My conclusion is that this indicates a 105 V charge voltage is programmed for all ten algorithms as suggested by Pdove. The consistency of the LED color indicators suggests that the charger is going through some basic check routine that requires 11 second intervals before reporting even though the current measurement is zero at 105.2V.

During the iterations of the 25 cell tests (101 V), the current during each test ramped up at about 2 A/sec until it reached 12.5 amps. Each test repeated consistently the same way. The cells gradually charge a few tenths volt higher from the start of testing until completion of the tenth test. This again strongly suggests that the programmed voltage is 105 volts in each algorithm. Due to the chemistry limitations of the cells, the testing for the 25 cells could not be allowed to exceed 103.7 volts and so each test was conducted for only about 20 seconds for each. The measured electrical current is the same in each test leads to the conclusion that the electrical current is programmed the same for the 10 programs.

 

[914EV]

Is the charging algorithm programmable? Examples are at this link.

https://forums.aeva.asn.au/viewtopic.php?t=3110

The voltage is programmable. Is the current programmable?