Batteries and Things: New Solutions for EV Builders

After a week off, we did get a video out this week. It's a little hosed up. I have the new Final Cut Pro X editing software and it has a few problems I'm struggling with.

We had some news on the J1772 front. Clipper Creek actually made some sort of internal error and SHIPPED us one of their charge stations in exchange for money - about $3000. This is NOT a 70 amp charger as I said in the video, rather a 40 amp model CS-40

It uses the white Yazaki connector. It's pretty sturdy. And it's $3000. This will give us a baseline for J1772 charging.

For most of our viewers, somewhat more important is being able to fit your build so that you can charge using J1772 - and perhaps at a somewhat lower cost.

We have published the basics in the past with a couple of resistors, a diode, and a switch with a J1772 receptacle. David Kerzel is the President of the EV group down in Florida and a hobby machinist. He's done a lot of small engines and so forth. But today, he has ModularEVPower, a web site offering J1772 components for home builders and he has come quite a ways very recently.

We received one of his machined billet aluminum J1772 charge ports. We can get these ports in a plastic model from China. But I am a sucker for machined aluminum pieces on our cars and this is very gorgeous.

Second, he has brought the resistors, diode, switch gig to a new level with what he calls an Active Vehicle Side Control Board at $30 each. This actually uses the proximity switch in the plug to activate the charging process. Once the switch is closed, it does the voltage divide down to 6v on the square wave to start the EVSE sending 240vac power. It ALSO closes a relay that has the common, the normally closed, and the normally open contacts all available for your use. You can use this to interlock a charger, light a light, or whatever. Very nifty and I think quite cool.

Finally, he has the guts of a the J1772 Electric Vehicle Service Equipment or EVSE - the EVSE Control Module.

This is what you connect to the plug end proximity pin (5) and pilot signal pin (4) to perform the J1772 interlock sequence. It features a switch allowing you to set the output current level which is encoded properly in the 12v 1 kHz square wave. It also has a 12v output to energize the contactors. You'll need a 12vdc power supply and contactors to switch the 240 vac phases, and you have the equivalent to the Clipper Creek EVSE. Of course you also need the plug and cable, and an enclosure. A GFI circuit breaker in the panel would be a good thing. But certainly you can build your own. We use replica gas pumps. You can use a pumpkin if you like.

Duane Ball and Scott Smith engage us with a video report on the Porsche GTS (904) build they have been working on. This is the latest Chuck Beck replica of a 1964 Porsche race car that slightly over 100 were ever made. Special Editions has been putting them out and sold OUT of their first set of these. They have increased the price of this roller now to $63,000 to meet demand - that's with no engine. Duane has essentially completed his build to the point of first drive/EV grin and is working off some DC-DC converter issues and a problem with his tachometer sensor. Waiting for a VIN number in New York. But the car and build are gorgeous.

We also did a bit of battery testing this week. I have moved my test bench from the home garage to the new facility where I have LOTS of room and now quite a bit of electrical power. And so we did a bit of cell testing.

I obtained 16 of A123's 20 Ah M1 HD cells. This is a 20Ah pouch "prismatic" cell that is definitely a Lithium Iron Phosphate variant, which we like and use. The spec sheet has it at 3.65 and 2.0 v. We found it operates just as our Thunderskies with respect to voltage, charging and discharging although the climb and dropoff are a bit alarming at the end. That may just be our inexperience with such small 20Ah cells.

In any event, their claim is POWER and they do indeed deliver it. We were seeing sag voltages of less than HALF what we get from the Chinese variants for the same current load. They are very stiff. In American fashion, they don't quite put out 20Ah as advertised. We like the Chinese style claim where they call things 20AH and provide 21 or 22. Not on these.

Of course, A123 has been unbelievably snotty about the whole thing. We got these from OSN Power, a Chinese company.

One of the advantages of these cells is a 127 wH per kg energy density, along with the power. Any weight from the module build would detract from that - and any expense would exacerbate teh first disadvantage.

If we can figure a super cheap super light way to do all that, we may pursue a build with these. But it would be to get titillating video. I don't see them as an alternative frankly. They are just too expensive and too complicated to use. They might get you a few more miles down the road, but they simply cannot compete with our lego block cells we use now. If you want to build a racecar, perhaps. But a viable vehicle? I don't personally think they warrant either the price or the complexity. They are incrementally better at some things with an exponentially higher cost to deploy. We have followed this company for years, and they remain a LOSER in battery development. The only company they've really sold on the cells are very small outfits and Fisker and they did Fisker by giving them the batteries essentially - a $30 milion investment in Fisker if they would use their cells.

John Plasma Boy Wayland and Rich Rudman have done something similar with Dow Kokam Cells and for the same reason - power output, once John's "Dream Came True" and they gave him the cells gratis. Kokam also designed a module for them which they had most of built at a custom plastics CNC plant (again gratis) with hardware done by Jim Husted. The result is about 10 lbs of module for 16 of these cells, pretty much negating the density improvement and is just hysterical. Forgive me, I just had to laugh. This is so overengineered and overbuilt to no known purpose that I can't deal with it. I SAY that overkill is ALWAYS appropriate. In this case, they have taken this concept to extremis and beyond.

If we have to do all that to use Kokam or A123 cells, it likely won't happen. But I have some ideas for something lighter and less costly ( cost is no object when using other people's money). I don't know when we'll get to them.