Li-Ion BMS

As the Lithiumate BMS is selling steadily and requires less and less of my time for support and manufacturing management, I have now shifted my attention to a new design, the Lithiumotive.

As the name implies, the Lithiumotive is a Li-Ion BMS designed specifically for the automotive market, though its ruggedness makes it appropriate also for marine applications; its wide scalability makes it ideal for land-based, large storage facilities.

The Lithiumotive design is in response to the various request we received from Lithiumate users:

• “I need redundancy”
• “I need support for more than 256 cells in series”
• “I need a sealed product”
• “I need absolute immunity to electrical noise”
• “I prefer spaghetti wiring to distributed cell boards”
• “I love the Linear Technology LTC6802 chips”
• “I need active balancing”
• “I need to make full use of all the energy in each and every cell”

So I went to the drawing board, with the goal of meeting all these requirements.

So far it’s coming along quite nicely. The biggest challenge? Connectors. Selecting connectors that are automotive grade, sealed, available, not too expensive, can handle the high voltage or the high current, has taken many days. Other than that, the electronics and the software are easy, especially after they have been validated by the Lithiumate’s success in the field.

The BMS family consist of 6 modules:

• Master
• HVFE (High Voltage Front End)
• Slaves: wired, optical, spaghetti, redistributor

Lithiumotive module

A system requires a master, an HVFE, and one and more slave, of any type. The various modules communicate through a dedicated CAN bus (digital BMS) plus a daisy chain (redundant, analog BMS).

The Lithiumotive is a professional product, and will only be marketed to professional industries (we will continue to provide the Lithiumate to hobbyists). Its release has not been announced, but it will be no sooner than the 2nd quarter of 2011.

We are in Seattle, WA, for the bankruptcy hearing of EV Components (or what’s left of it).

This area is a hotbed of EV related activity!

Yesterday we visited with Rich Rudman, of Manzanita Micro, in Kingston WA.  We saw Manzanita Micro’s new headquarters: an elegant, spacious building with lots of garage space and tasteful offices up stairs. Rich’ “gnomes” are busily building product (pretty much everything is done in house), while he and his partners are developing more and greater things. One of those partners is Mike Willmon, formerly of EV Components, who we were glad to meet.

Later, I met Jake Oshins, a fellow Sparrownaut, who showed me his Li-Ion converted Sparrow (I did a similar conversion to my Sparrow).

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The bankruptcy hearing was in Downtown Seattle. As we were walking out of the parking lot, we heard a scraping sound: it was a sports car scraping its bottom entering the parking garage: a Tesla. A Tesla? I wonder who that might be!

Upstairs we met Ken Vatz, the lawyer hired by EV Components’ clients to do a class action suit against that company. Nice man, obviously quite smart. We also met Dave Kois, finally, after such a long time working together long distance.

The hearing was in a courtroom. The trustee and his secretary were sitting on one side of a table, facing the audience. Chairs across the table were for the people being questioned. The meeting started exactly on time, and the first two cases were heard rapidly.

Then came the turn of EV Components. The man from EV Components and his lawyer joined  the Trustee and his assistant at their table. Three of those people were dressed professionally and appropriately for the occasion.

We all sat in the second row, yet we could not hear very much of what was being said. Ken and Dave moved closer, to hear better. But it was clear that the Trustee knew what he was doing, had studied the case, and was quite good at challenging the man’s statements with pointed questions.

Afterward, the Trustee asked if there were any creditors in the courtroom. Ken stood up and gave a succinct but effective rebuttal to the man’s claims. At one point the lawyer objected to Ken’s line, but Ken quickly replied and continued making his points, ending with a request for dismissal of EV Components’ bankruptcy request. The Trustee replied that that was an option, but that he needed to consider other options as well, and that he wished to talk to his own lawyer before he could make a decision. He was definitely non-committal.

Dave offered the Trustee a list of EV Components inc.’s inventory at the time of his departure in April, which the Trustee gladly accepted given that the man had stated that the last inventory was taken in March (before EV Components inc. was formed).

The Trustee asked whether any other creditors were present, so I stood up a briefly described that EV Components owes Elithion $ 12,8 K.

Then, the Trustee closed the hearing. The man and his lawyer left first, quickly, without looking at us.

Just returned from the Formula Hybrid contest, where nearly 30 teams of students ran their HEV race cars.

This is the second year that some cars used Elithion’s Lithiumate BMS. This year I was tapped as one of design judges. That was actually fun! I really got into it.

Going in, two cars used the Lithiumate BMS, Politecnico di Torino’s SquadraCorse and University of Vermont’s AERO. By the end, an additional car had a Lithiumate: Manitoba’s UMSAE : their original BMS (from I+ME Actia) blew up, so we scrambled to find a Lithiumate BMS locally; an Elithion client in Boston donated the cell boards, and the AREO team lent its spare controller; we adapted the donated cell boards and installed them in the vehicle overnight.

After seeing the disparity in understanding of Li-Ion BMS issues among the teams, I organized an impromptu seminar on Li-Ion cells and BMSs, which was well attended, especially given the short notice and how busy the team members were at that time.

Find pictures and details in our Formula Hybrid page.

Carl Guichard of Global E, a contender in the Automotive X-Prize, asked me to fly to New Orleans to work on their car.

I spent 2 days there (mostly waiting for them to get the car ready for me to work on), but once the car was ready we worked very rapidly in bringing it to the point that it functioned as desired.

The people in the Global E team are quite nice and appear to be quite capable. I wish them the best in the Automotive X-Prize contest. (At this writing, 7 entries use our Lithiumate BMS).