Tell me if I”m correct. And tell me if I’m not. I rather see the future of EVTV as moving somewhat away from our various builds, though we undoubtedly will always have some project going. And more toward viewer contributed videos of their builds.
This video kind of qualifies. We have Richard Rodriguez with a report on a build he really finished in 2010. But 20,000 miles later, living one day at a time BMS free, he HAS made some changes. Instrumentation – some great looking new rims, two more cells, a larger charger.
Jeff Southern being on the other end – still wrestling with the dust and dirt of finding his car underneath all that rust, but starting to work on mounting a motor with an adapter.
And star of this week’s show – John Hardy. John’s got a kind of wry British understatement I find enormously appealing. But because he’s not ranting and raving quite the way I do, do not miss the point. Five hundred cycles on some Headway LiFePo4 cells with a comically egregious NO on the concept of cell drift. That is the END of the cell drift debate as far as I’m concerned.
I originally started Boardwatch Magazine and wrote every word in it for several years. By the time I sold it to Mecklermedia, we had 22 regular contributors and I pretty much did the letters to the editor and an editorial. The 22 scoured the ISP space digging up pretty much everything that as happening there and we became more or less a mirror of the industry. You couldn’t hook up your grandmother without it showing up in our rag someplace. I kind of see this developing at EVTV only more on a build by build basis. Everybody does things slightly differently. Some work out. Some not so well.
We had a visitor this week. Ed Cochrane is trying to get off the ground selling Sinopoly Cells and we promised we’d take a look at them if they ever appeared in real time. From my interaction with Patrick Wong and Sinopoly, I would say Ed’s biggest challenge is dealing with Sinopoly. These were money people who backed Winston Chung and NOT battery people. They are curiously inept at either building batteries or marketing them. ANd their arrogance and vanity are just beyond belief.
Ed’s a returning veteran from Afghanistan. He has an oddly honest demeanor that is going to hurt him in some ways but I found engaging. He had two direct criticisms that I was fascinated to hear.
The first was that we were long and boring and over the head of many of our potential viewers. The second was that our sales of components had enraged some of the existing component sales web sites. I was kind of delighted with both criticisms.
We ARE long and boring, and quite over the head of those new to the EV world. Not quite so long and boring to those deeply involved in it. In any event, that’s what fast forward is for.
We went through this at Boardwatch. We have to either be the intro for newbies, or do things in depth. We choose B. I’m sorry what was A again. First, I just can’t DO an article on how XMODEM works over and over again. IT is boring for me. Second, it is easier for the new among us to GET up to speed, than it is for all the rest of us to review why a generator and motor won’t drive each other forever, over and over and over. And unlike the magazine, which becomes unobtainable after a few months, video is forever. WE have our FIRST video still online and in fact it is in the number one position on our home page. It of course remains the most watched video we’ve ever done. Party like rock stars. We still have a convenient response to an inconvenient truth and when I go back and view that video, I’m struck by how LITTLE we have varied in tone or message over the hundred and some odd videos since. I stated very clearly then that our mission was to get 100,000 guys about my age to take responsibility for their world, and CHANGE it, by building their own electric car. I truly believe that is the TIPPING point. And while I live and breathe that is where we are headed without variation, apology, or redirection.
But we are just NOT for the Plug-In America crowd or even the Electric Vehicles of America membership. People who advocate electric drive simply aren’t sufficiently interesting to me personally. If you’re not building, you’re watching. That’s great. But its not what we are about. People who have great ideas about what SOMEBODY should do about a problem are not interesting people in my experience. But people who do things and make things happen ARE. So being an ADVOCATE for alternate fuels means little to me. One of the presenters at a very large EV conference recently asked the audience how many people actually DROVE electric cars. The response from the crowd was shocking to everyone there. Maybe 5%.
If you DRIVE electric. More interesting. If you BUILD electric, much more interesting yet. If you ENABLE building, more interesting yet. If you think electric cars are cool, and have some great ideas for perpetual motion – go away. There are other web sites just crying for your presence. They get BIG numbers of people. We have just a few. They’re the few I want.
So we very consciously design our show to drive copper foil helmet freaks away as fast as we can get them to move. We pay about 30 cents every time somebody downloads a video. These guys are NOT what we are after. Even the NPR spot at last year’s convention, which I’m told was the most listened to segment that day and had the highest listener response, caused 11,000 downloads. It made our attendees feel great and our vendors at EVCCON 2011 feel even greater. It cost me $3400. Small price to pay, but we did have to write the check.
And that’s the game. Out of the 11,000, we probably did pick up 80 or 90 regular viewers and 20 builds current and more of the 80-90 to come as they get comfortable with the idea that they can do it – with families and lives and no time for building a bird house much less a car. Face it, this game takes ducats and commitment. I never meant to imply otherwise. Complaining, even loudly, does NOT really change the world. It just increases the background noise for those who drive change.
As to the online retailers of the wares of EVdumb. I have to laugh. I try to be sympathetic. It IS early in the game and the industry is really entirely in its infancy. I understand their struggle just to survive. But you’ve got to be kidding me. We personally contacted every major and most minor players in that space and tried to sell them a commercial at historically trivial rates – truly trivial even in their budgets. To a man they told us we were little and ugly and our mother dressed us funny and would never grow up to amount to anything and weren’t worth advertising on if it were free. We got a little encouragement from the developers, such as EVNetics and Masterflux, and NEtgain and Winston Battery. But NO ONE from the retailer side. Imagine my surprise to learn that their margins are in many cases higher than the developers?
As I think the developers should sell directly, lower their prices and up THEIR margins, cutting out the middle man, none of this makes any sense to me. But that’s where it is at at them moment.
So now we’re trying to find cool stuff for our viewers to enable their builds, and kind of sidled into the online component sales without master plan or mission beyond originally improving their cell connections. And the online resellers are enraged? How can that be? if we are not effective as an advertising medium, then how could we possibly affect their sales? And if we are, why weren’t they advertising?
The answer is a little bitter, and does not match my insistence that everyone is a gentleman and scholar and that the world is really a great place, because there really are a LOT of GREAT people in it. The answer is they LIKE it that we were drumming up business for them, and they would graciously take advantage of that as long as it was A FREE RIDE. So as long as I was paying to promote their business, we were ok. But if WE made the sale instead of them, that was another kettle of fish. Indeed they are ENTITLED to the results of our efforts in some way…
Let me offer you all a little hard won advice from someone who has been extraordinarily blessed with the resources of our world, including hard cash, and has the scars to prove it – Obama’s view that the government actually did it notwithstanding. THere are takers in this world and their are givers. NOT ONE of the players who thrive in our economy is a taker. Takers never make it. They ALWAYS wind up selling off the office furniture at 10 cents on the dollar. And they ALWAYS have a million excuses why the forces of the universe conspired against them and the failure wasn’t really theres. Givers actually have to struggle to avoid success. It comes at them from all directions and can be a bit overwhelming.
Givers find ways to leverage every breath to have maximum impact on minimum effort to do something worthwhile they believe in that will make their world a better place. People just naturally send them money in the mail. They are never sure why.
Train yourself for success. If someone OFFERS you a free ride – don’t take it. Run, don’t’ walk away from it, or find a way to double down where you pay more than its worth. While counterintuitive, it’s how it works. Never take anything for free. Pay it back double or pay it foreword double. Just do not allow yourself to GET without GIVING. It’s like painting LOSER on your forehead with lipstick. Pay the price. And truly, as Bob Mahoney told me years ago, if your mission is to make money, you don’t have a sufficiently complex set of goals to build a life, much less make any money. If i recall all the details, he sold EXEC-PC for $21 million. I think he has his own island now off the coast of Florida. Interesting guy. But can’t stand to deal with the public. Very private.
I personally know dozens, if not hundredsn of multimillionaires many times over from the Internet bubble. And despite the common myths, this holds true in 100% of the cases. I cannot think of a “gimmee” guy that made it from that era. Not a single one. ANd there were plenty of them. They just ALL failed ultimately. They thought they were winning for awhile. But one by one, the universe eliminated them from the pool somehow. I know one particularly loud and high roller from that period who’s now a night watchman at a dairy. It’s as much a part of the rhythm and pace of the universe as sunlight and rain.
No doubt when they fail, these guys will blame us for it. They always have to reconcile failure to an outside force. They MUST rationalize it to live with themselves. But it is pathetic to watch.
If it helps any, we price a bit above the market on everything, specifically to avoid damaging the industry or starving out developers. We pay whatever they charge. And we pay promptly. ANd then we try to value add on everything we sell. If the world were perfectly priced, we’d sell nothing because everything is available somewhere else for less money. We’re probably the only online store even attempting to sell at MSRP. And our mission if you do buy from us is to make sure you get MORE than you paid for. How can that work? I don’t know. It just always does. People are pretty cunning with their ducats. And they see right through our scam….
Actually they see through YOURS as well which is the problem….
As soon as it moves from an adversarial “him vs me” battle for the final farthing to fall to the carpet, it becomes a collaborative transaction to meet needs and accomplish goals. Very different relationship. The former is so normal in the “zero sum game” view of our society, some don’t know how to play at a higher level. Oh well… That’s why there are more night watchmen than there are millionaires. As my daughter says, “circle of life, circle of life, move on…”
And the bubbling cauldron of innovation continues. Eric Kriss devised a simple billet aluminum frame for a Marinco NEMA 5-15 three prong male recessed plug. It allows you to mount it on the outside of your car easily and securely. We do J1772 now. And he wanted too much money for the device I thought. But following the principle, we ordered 10 and paid promptly – like 10 minutes later.
I received the frames. Also ordered 10 of the Marincos. As soon as I fit a pair of them together, I got it. Just freakin gorgeous. And are we EVER going to be where we don’t want to take advantage of an opportunity charge someplace that doesn’t have J1772? Like grandmas house? OR daughters house?
In twelve seconds with this thing in my hand I got it. Brilliant Eric. It’s just gorgeous. We’ll never build another car without one. Again. People just send me stuff in the mail… I could probably make a living just selling these for Eric. Boats. Big trucks. It goes way beyond EVs.
Within a year Marinco will rip it off themselves.
Let’s talk a little bit about Lithium ion batteries and John Hardy’s results. Like chess, bridge, and hand grenades, battery discussions theory and discussions can be played on many levels. I have a bias toward useful clarity of communication at the expense of deep technical accuracy and precision of word choice. But I’ll go a little deeper here.
We do not use battery management systems as they are discussed online by EV enthusiasts. But at the same time we strongly advise you to not overcharge and not over discharge the battery cells. This is because that is how you can
1. REduce cycle life
2. Destroy them.
Overcharging does a couple of things. BUt in extremis, you have basically extracted all available lithium ions from the LiFePo4 cathode, and moved them to the carbon anode and intercalated them there. If you continue to apply a voltage, SOMETHING is going to move from the cathode to the anode. The first thing the cathode gives up is LITHIUM. This does a couple of things. First, it deposits lithium metal on the surface of the anode. This appears as lithium metal plating. And that restricts the capacity of the battery to intercalate and deintercalate true lithium ions from the anode.
It also leaves the cathode as a strongly oxidative compound. Our electrolytic solvents are mostly carbonate, ethylene carbonate (EC), dimethyl carbonate (DMC), and diethyl carbonate (DC). When oxidized, this results in CO2. CO2 is of course a gas and this is what causes the swelling of the cell. At some point the cell vents and despite the mysteries described by the experts, it is really almost entirely CO2. But it can be explosive enough to vaporize and carry some small amount of volatile and
indeed flammable compounds of the electrolytes. In this vaporized form, they can cause a flash fire. As they are mostly essentially ethanol, it is not a high temperature situation really.
If we continue to charge the cell, we cause a rise in temperature. At some conduction level, the cathode begins to release oxygen, which reacts with the electrolytes leading to thermal runaway. This process really cannot be stopped until you run out of cathode material.
Let’s talk about THAT a little.
CATHODE RUNAWAY TEMPERATURE
Lithium Cobalt Oxide LiCo 266-302F
Lithium Nickel Manganese Cobalt Oxide – LMC – 338-356F
Lithium Manganese Oxide LiMo – 482F
Lithium Iron Phosphate LiFePo4 – >500F
And now you know why I am very leery of LiCo cells and a big fan of LiFePo4 with regards to safety.
There is no actual fully charged charge voltage. The CC/CV thing is a recipe. In theory, the open circuit fully charged voltage of a LiFePo4 cathode is 3.45volts. Because of certain conductivity additives such as carbon it is actually 3.40v.
But when charging, we see a higher voltage. To GET there is a function of voltage and current. We could charge to a lower voltage, but leave the low level current on longer. Or a higher voltage with less holding current. These are RECIPES to charge the cell. Not actual cell values.
But it is ALL we have that we can measure. And so we see a voltage. When these cells first came out, the magic voltage was 4.2v. THis was because above 4.3v you started to get into some overcharging issues. The manufacturers have steadily revised this value DOWNWARDS, in almost precisely the manner I did four years ago. And for the same reasons.
Believe it or not, there are no absolutes in cycle life either. I can give you a longer cycle life for the same battery simply by giving you a lower charge voltage. Approximately thusly:
4.3 volts – 150-250 cycles
4.2 volts – 300-500 cycles
4.1 volts – 600-1000 cycles
4.0 volts – 1200-2400 cycles
3.9 volts – 2400-4000 cycles
Now let me say something that will REALLY raise some ire. What John is showing you is CHARGE voltages which have LITTLE to do with voltage of the cell. When we are charging, we are FORCING the lithium ions to deintercalate from the cathode material, migrate through the electrolyte, and intercalate into the carbon anode. This process is a little mystical, and further delayed by the SEI layer on the anode. But basically it is not a covalent chemical combination. The ions literally migrate to points in an orthorhombic crystalline structure where they can attach or disattach to the crystalline structure at the corners. Think of this as “tunneling” through a maze. We talk about this as a diffusion constant or diffusion delay.
In John’s charge curves, you see the cells diverge as they become fully charged. When charging in the flat part of the curve, the lithium ions have no difficulty finding places to lodge in the crystalline structure. But toward the end of the charge they do – depending on the thickness, porosity, and olivine structure of the crystalline material. This varies as part of the construction of each cell. I suppose it has SOME relationship to capacity, but not what you think. It is a diffusion DELAY. And so these voltages are NOT REAL. They are manifestations of diffusion delay at the end part of the charge.
If you idiotically try to BALANCE those voltages with a BMS, you have NO IDEA what you are doing but you are certainly NOT bringing them to the “same state of charge”. Indeed your efforts to balance the pack may have just the opposite effect.
In ANY event, if we don’t charge them that far, we do not have to worry about diffusion delays at the end of the charge cycle because we never GET to the end of the charge cycle. The lithium ions that we intercalate ALL have handy places to quickly reside.
You will notice that most of the cells fall to something LESS than 3.4volts within an our or two and we talk about this as “relaxing” or bleeding off the “surface charge”. Not a bad description. The cloud of ions trying to intercalate and having to tunnel a bit to find a place do eventually find a place. Occasionally you will see a cell that “sticks” or doesn’t actually fall below 3.4v. Don’t worry about this. It will sort itself out after a few charge and discharge cycles. If it is persistent, you have overcharged the cell and damage has been done.
Charging cells in series becomes more complex. Some cells have smaller capacities than others and would reach state at different times. The solution is more of the same. Let’s drop the charge voltage from the manufactures recommended 3.65v down to 3.50 or even 3.45 volts. We indeed have less stored energy and give up range. But we get out of the diffusion confusion, and FURTHER extend the cycle life of the cells.
For most of us, the THREE TIMES ADVANTAGE of LiFePo4 cells over lead acid cells leaves us with plenty to play with with regards to range. But it came at a price – $10,000. So we think CYCLE LIFE is the most important determinant and
we’ll give up a mile or two of our now 100 mile range to extend the life of our cells. Richard Rodriguez believes that by charging to a lower value and not over discharging that he will REALIZE the 3000 cycle claim of the manufacturer.
Indeed, should he live long enough, and not want to upgrade his cells, he may well be looking at 10,000 cycles or 15,000 cycles before they reach 80% capacity. He just drove his car 140 miles.
And so we continue to advocate that top balancing with a BMS is the most idiotic concept since aluminum foil inside hubcaps to fool police radar guns. ANd that undercharging is just like putting money in the bank.
That leads us to over discharging.
What happens when we over discharge our cells? Well, we are moving lithium ions from their cozy location in the graphite on the anode, through the electrolyte and into the cathode. If we continue past a certain level, a couple of things happen AGAIN. First, we again go into oxidation and produce CO2 and our batteries swell. Second, we start to emerge copper from the copper foil the anode rests on through the carbon in a streamer we will refer to as a shunt. It penetrates the separator and connects to the next “cell” that is, between two foils inside the cell. ANd it shorts them out. The more of them that are shorted, the less cell you have active. And they cause heat. The most common cause of death is over discharge. You cannot make the shunts go away. A little swelling is telling. But the shunts are death.
Because of the dynamic nature of our cell voltages under various current loads, it is devilish to produce an automated system to cut off our cells based on voltage. We use coulomb counting. We sum up the amp hours and at some level, we shut off the car. If you built the car, and paid for the batteries, you can do this yourself by watching the numbers or even watching your odometer. But if you have a wife or daughter or son who drives your car, understand they may not be similarly motivated and when weighing $10,000 against arriving at a hair appointment on time, you all may not share the same values.
Enter daughter mode. In the Speedster, we describe a simple circuit using the JLD404 amp hour counter to count amp hours and dramatically cut back the throttle if you reach a certain level. We also talk about how you could entirely disable the car at a second level preventing its use.
Neither is fool proof. We assume if she knows little about the car, that she will not realize that by pressing the down arrow key for three seconds this resets the JLD404 to zero amp hours. You may know this and it might be pertinent to keep the information to yourself.
Even that’s a bit problematical. The round trip charge and discharge is not 100% efficient. And so a small error in your amp hour counting will be incorporated with each charge. For absolute accuracy, after fully charging your car you should Synchronize your JLD404 with the charge state by pressing that down arrow for three seconds and zeroing out the accumulated errors. This really isn’t necessary EVERY time you charge. But most of the time. I glance at the value to make sure the charge occurred and I am indeed fully charged. If it’s within an amp hour or two, I assume the charger has fully charged the battery, and zero it out. If a larger number is displayed, I assume the charger did NOT fully charge and terminate and some investigation is in order. Never reset after a partial charge.
But it mostly works to avert disaster on over discharge.
The leaves the final case, that what do you do if a cell just fails at the end of its life. Won’t that take out all the other cells?
Well yes and no. We have experienced few cell failures. But if it does fail, it is unlikely to do much damage to your pack before it tells you. Most likely, your car won’t’ work vey well. If it starts to behave strangely, like say, not moving forward, some further investigation might be in order. Do it manually in a garage. Not while driving.