This week the Brain is off to see his parents in Southern California. They are not as young and pretty as they once were and indeed Lou is facing open heart surgery. If you are accustomed to prayer you might put in a word.
Leaving me loose in the shop by myself. Actually, I enjoy solitude and particularly in the shop. If I set something down, I can kind of count on it being there when I come back. With a single other soul in the building it is always remarkable to me. I could build a trick double throw me down quick disconnect air powered overspeed protected refrigistastitator flavis waven that no one on the planet but myself even knew what it was, much less have a use for it, and lay it down on a bench immediately on assembly.
If I turn and refill a tea glass, when I come back 12 seconds later, the damn thing will have disappeared completely. A search ensues. EVERYONE in the shop SWEARS they haven’t touched a thing. 45 minutes later I find it on the SINK in the bathroom.
OH YEAH. Is THAT what that was? I was wondering? So I took it into the bathroom. NOW I know what you were talking about.
I actually had an incident this week, again with an object so nondescript NO ONE could have a use for it EVEN ME, in theory, but I did. It had been moved and when I complained I was told in no uncertain terms by the only other person in the shop that they hadn’t done it. When I noted that there were only two of us, he became THOROUGHLY incensed that I would “call him a liar” and threw a total fit. Without missing a beat, he then noted that he had only moved it for “safety reasons” and because it was in his way. ???? So he was INCENSED that I would call him a liar, which I never did, and then confessed to lying about it, which he did.
I apologized profusely of course and noted that I wouldn’t’ for anything in the world have him offended in any way. And indeed to prevent any POSSIBILITY of a future occurrence, I invited him to leave the shop and our employ as quickly as he could assemble his train.
Alzheimer’s is not precisely a disease in my family. Picture it more as a tradition. So I kind of feel like Helen Keller after her parents have rearranged the furniture for the twelfth time.
So I kind of had a good time this week, once Rod had been promoted to whatever he’s doing now, and I’m rattling around the shop by myself. It has been wonderful. It’s true I am not as good as those guys at fabrication and just being able physically to reach things and lift things and so forth. But I actually got quite a bit done, albeit in piddling ways.
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Not really shown in this weeks’ episode. I got some 4 AWG cables run from the Manzanita to some terminals under the truck tied in with the J1772 plug wires. This gives us much stronger cables to carry the current for our PFC-75. I’m so accustomed to chargers that put out 20 amps, that having a 75 amp monster is a constant reminder. The little 10 gage wires I had on it, normally overkill for charger duties, were getting very warm.
As many know, the Manzanita is NOT my favorite charger. But this particular unit we spent about $4500 on several years ago when it first came out and it is capable of 75 amps at up to 400 volts. That’s pretty stout.
Despite Manzanita’s assurances that they are all fully capable of 75 amps, we get 68 amps or so into this one from the wall. That’s still pretty stout. And with a 400Ah pack, we need all we can get. At that high current level, it will still take six hours to charge this 76 kWh pack.
I’ve done something kind of goofy here and may pay the price. We’ve mounted the charger, and a DC-DC converter, on TOP of the polycarbonate lid of the pack. So now to get to my pack, I have to remove a lid with a n ever increasing array of wires and stuff on top of it. I added the little voltmeter we talked about recently from LightObject to it for example, so I can see the pack voltage at a glance. Turns out this little 5740TV voltmeter is really pretty accurate. I just love these things. I found an older JLD404 AH counter from these guys and got it set up in the lab and working and it is pretty nice. Voltage, current, hours, and AH all in one little device. Problem is, they don’t sell it anymore. They sell a JLD404, but it does something else and no longer does AH. But we’re talking to them about getting them again.
I also tied the charger to the pack INSIDE the box. This poses a little problem I hadn’t thought through. I need a hall effect device and a shunt device for current measurement and in order to work, it has to be inside the loop of both the controller AND the charger. In this case, that now means inside the battery box. So my electric car is moving one piece at a time into the battery box in back. And I’m not sure I can stem the flow of parts into the area.
We did bleed the pack down using our Aurora Inverter – basically running the shop off of the 76 kWh pack for two days until the pack was drained. Then I used an old Thundersky 30 A charger I have laying around with big jumper cable clips on it, to individually charge each cell up to about 2.80v – then letting them fall back to about 2.75. We did this to all 57 cells until they all read 2.75 +- 0.05v. At that point, we hooked our Manzanita back up and charged it to 205 volts. This will be about 3.6v per cell and is high enough for my purposes. Again, I like to undercharge a bit and we have a huge pack here.
As noted in the video, we did build a little heater for the Vantage GreenVan. Brain had reported in from California that he had visited HPEVS and they were working with Vantage GreenVan on a LiFePo4 version of the van. We’ve been enjoying one for some time. But it has a little diesel heater that I’m scared to death to even turn on. So I wired my daughter up a little electric heater using two of the by now familiar PTC heater elements and a Kilovac relay.
And as promised, I show the damage done to our A123 module attempts and even pry open one of the cells to look at the very different looking cathode on this cell and talk a little about the patent disputes over this cathode.
I’m still mystified by our losses there. This week I’ve made TWO little modules with 6 cells in parallel more like our prismatics. They are champions. About 117 Ah – full spec 19.6 Ah per cell.
I DID notice something that is a little problematical in an electric car and kind of hard to test. If I fully discharge a set, and then immediately full charge it, it looks like ti has lost capacity and reaches a high voltage quite prematurely. If I let it then set overnight, I can add another 10 or 15 Ah to the cell the next day with no harm at all. This is NOT like our existing cells. It is quite strange behavior. And it might explain some of our damages in the modules. I was running it HARD to discharge it and pretty hard to charge it and doing it quite back to back based pretty much on what it OUGHT to take.
Of course, I don’t want to have to leave my car overnight before fully charging it? That makes no sense.
IN any event, this week I’m working on a rubber mold to make cells that look like CALB 180Ah cells but of smaller size and HIGHER power of course. A 120Ah cell would have a current capability from our tests of about
2750 amperes. Imagine driving the Elescalade on 57 of those. 57 x 6 x $26.60 = $9063. That might seem steep but it is some less than the $25,000 we have in the back now. Of course, again that would be a scant 23kWh pack and we would probably be limited to 25-30 miles on such a pack. But it drives home the point of those high power cells, we could still drive the two Soliton1’s to their limit easily with such a pack or an even smaller one of 90Ah for example. And so we can use less expensive battery packs for shorter ranges. Not my style, but an option.
The problem of course is that it would take quite a bit of “sweat equity” to convert boxes of individual A123 cells to our prismatics – including hardware, resin, and so forth. So long run, I’m not sure what would be saved. But many of our viewers aren’t concerned about the long run. They’re concerned with limiting expense in the right now. If they’ll settle for less range, these cells appear to be an option.
The cells from VictPower seem to be testing much better than the cells received from OSN power. We’re clearly up over 19 Ah with these. We are charging to 3.65 volts and discharging to 2.50. There is indeed some power between 2.50 and 2.00. We’re content to let it remain there.
Jack Rickard