# Best way to treat rechargeable batteries

Discussion in 'Architecture & Engineering' started by Fraggle Rocker, Aug 15, 2011.

1. ### KilljoyKlownWhateverValued Senior Member

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Yeah! Nothing sadder than a little kid begging for a new battery. Only the toughest parent would say no.

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5. ### quadraphonicsBloodthirsty BarbarianValued Senior Member

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Lithium batteries haven't figured into the car sector so much - and lifetime issues are a big part of the reasons for that - but apparently this is changing these days. However I get the impression that the ones used in cars utilize variants of the technology that sacrifice certain types of performance (power density, etc. that are more important in smartphones) to improve lifetime and other aspects. The Tesla Roadster apparently uses basically laptop batteries, but configures them in modular "blade" subsystems so that you can easily swap out dead portions without having to chuck the entire battery system.

Yeah, SSDs are neat, but still a too pricy. I definitely drool over the prospect of having zero internal moving parts in my laptop (except maybe a fan), much better seek times, possibility of instant booting, immunity to shock and magnetism, etc. And if the power consumption and weight can come down in the process, so much the better. All they really need is some drop in the price, and it'll be a no-brainer to use them for anything except major data storage stuff that needs many terabytes of space.

7. ### KilljoyKlownWhateverValued Senior Member

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Right now electric cars have a serious range problem, but I truly think the current battery technology is going to advance the the next generation within the next 10 years, at least there is a great deal of pressure and financial incentive to do so.

One experience I can recommend for desk tops. If you have to have a real power system, build your own. It's not that hard to do, and shopping for all your own favorite parts is a great experience, not to mention how you feel when It's done and works as expected or better.

8. ### OnlyMeValued Senior Member

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I have a 1st generation iPad. The instructions that came with it said to run the battery down until the low battery warning appears at least once a month to extend the battery life. That happens at 20% charge and when discharged to that extreme the charger cannot keep up with both the demands of charging and continued use of Wifi or video. From about 60% and above there is no issue. I think it uses a Li polymer battery. Li batteries are known for their ability to both take a charge fast and to discharge fast and require a charger designed them specifically.

An older Mac laptop had a real battery issue in that leaving it plugged in killed the battery in short order.

I have a trike, with an electric assist. It uses a Li battery pack. I am not sure of the particular type. The stated life expectancy was 2000 charge cycles. At which time it would have an 80% of the original capacity charge capability. It also mentioned that even when placed in storage the battery should be charged once a month. I usually charge when drops below 3/4 charge, but that is a range related decision.

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Lets see if I owned an all electric car and used it to get me to work and back every day and charged over night every day, we would be looking at 5 or 6 years for a battery change out. As much as I would like to own an all electric car the short range and battery $5000 balloon every 5 or 6 years makes it a real bad investment. It's a good thing I don't feel the same about Hybrids. 10. ### OnlyMeValued Senior Member Messages: 3,914 That works out to about .027... Cents per mile for battery life and that assumes a starting range of 100 miles and an end range of 80 miles on a full charge. In So Cal where I live the baseline rate for electricity is$0.13/Kwh and that includes a proration of the taxes and service fees. That puts the per mile cost at around $0.16/mile. The current cost of a gallon of regular gasoline at a discount station is between$3.85 and $4.00/gal. That works out to an equivalent of about 24 mpg for the first 180,000 miles of operation. Most estimates for recharging costs are far lower than my estimates here. Add the fact that for an all electric vehicle you should only need to deal with designed in repairs.... How many people keep a car for 180,000 miles today? And what is a car's resale value at 100k? It is possible that the all electric, barring those designed in issues, may have a greater resale value than a conventional gasoline modle. Still though I like the idea of an all electric I am not ready to buy what is in the pipeline right now. 11. ### leopoldValued Senior Member Messages: 17,455 first of all solid state refers to transistor circuitry. but yes, what you say here is true for nicad type of rechargeable battery. it may also be true of lithium ion types too. this is not true for lead acid type of battery ( the car type ). deep cycling of a car battery will eventually ruin it. 12. ### Fraggle RockerStaff Member Messages: 24,690 We've had our 1978 Mercedes 240D for 33 years and 200,000 miles. It's a member of the family and has a name. But I agree, the new cars (even the Mercedes) are not designed to run that well that long, and people don't really want to keep them that long anyway. Our 33 year-old car, as good as it is, does not have anti-lock brakes or air bags. I sold a 1979 Mercedes 300SD with 180,000 miles for$600. Of course the heater core had crapped out (no heat, A/C or defroster) and that's a $1500 repair because it requires removing the dashboard and taking it out the hard way. It all depends on the technology curve. Electric cars are at the beginning of their technology curve where it's very steep. If the idea ever really takes off, today's models may not be worth much in a few years just because the newer ones will be so much better. When you younger people, who have spent your entire lives communicating, working and playing virtually with cellphones, MMORPGs, Facebook, etc., finally take over the management of America's workplace, you will not demand that your employees "go to work" every day because you yourselves will work from home. That will cause a huge drop in demand for automobiles, lower mileage for the ones that are bought, and at least a 25% reduction in the country's petroleum consumption. We may be able to afford the luxury and convenience of internal combustion engines. I know. But it distinguishes transistors, in which current flows through solid matter, from vacuum tubes, in which it flows through empty space. I figured I could use the same terminology to distinguish current flowing through solid matter from current flowing through liquid matter in a lead-acid battery. Please Register or Log in to view the hidden image! 13. ### nietzschefanThread KillerValued Senior Member Messages: 7,721 You've been in I.T related stuff a lot longer than me. They've been saying this for as long as I've been in I.T. If anything I see people getting summoned unnecessarily into the office more than ever. Until big brother gets to watch how long you take a shit at home, working from home will not happen. 14. ### PinwheelBannedBanned Messages: 2,424 Yeah, that and the "paperless office" which I'm still waiting for. 15. ### OnlyMeValued Senior Member Messages: 3,914 Both of those are diesel, no? Not a fair comparison to the gasoline engines most people drive. Very good machines. I don't think of myself as old at over 60 and retired, but I guess such distinctions are all relative. On the resale issue and newer technology, as long as the, then older tech is holding up, there will be a secondary market, as new tech is available. Think of how many folks are driving old vehicles, not like yours, now. But generally I think you are right waiting for a few of the newer innovations in the works is not a bad idea for us older folks who will most likely not be needing four or five more vehicles, in the future. Personally I tend to drive my vehicles to the junk yard. Though I will admit that seems to involve a faster turnover than it once did. I have owned used cars and even older model new cars in the past that held up better than most on the road today. 16. ### leopoldValued Senior Member Messages: 17,455 i actually thought you meant the "gel" type of battery. these are basically a lead acid type with the acid being held in a form of a paper towel or other absorbent medium. these types are usually no maintenance and spill proof. 17. ### quadraphonicsBloodthirsty BarbarianValued Senior Member Messages: 9,391 Yeah, I used to take that approach for about 10 years. Basically had one Frankencomputer that I'd periodically upgrade whatever part of. But it's gotten to the point where Asian manufacturers will sell you a sweet netbook for half of what even a bargain Frankencomputer would cost, so I chucked the old thing once some major components died. Now I'm all netbooks and smartphones, maybe pick up a tablet in the next year or two. Frankly, unless you're going to play Starcraft or Crysis or whatever you don't need a desktop, and I prefer dedicated game consoles for that stuff, so... give me light and portable, and leave the spec-reading and overclocking to undergrads with no social lives :] 18. ### quadraphonicsBloodthirsty BarbarianValued Senior Member Messages: 9,391 The term "solid state" is used in a variety of context ("solid state physics"), and specifically in battery technology, to distinguish from the various models that use liquids. Fraggle's usage is completely correct and standard. Even in electronics, it doesn't refer to "transistor circuitry," but to any electric system that consists entirely of solid elements (as opposed to vacuum tubes, gas-discharge devices, high-power liquid resistors, etc.). There is no requirement that any transistors be present: LEDs are solid-state devices, as are CCD's, PV cells, etc. 19. ### quadraphonicsBloodthirsty BarbarianValued Senior Member Messages: 9,391 They'd better be - it's an easy matter to purchase an ICE car that does way better than 24 mpg. Meanwhile, the latest federal guidelines require ICE cars to reach a fleet average of 35 mpg in 5 years, and 54 mpg in ten years - so unless electricity gets way cheaper, or they somehow drastically increase the mileage of these electric vehicles, I don't see how they're going to compete. Meanwhile, you're pushing the cost of a new battery out of the accounting - when that thing dies, your electric car is totalled. The cost of a new battery will exceed the value of the car. ICE cars don't come with a scheduled expiry date like that - sure, they depreciate and may eventually not be worth the cost of major repairs if something breaks. But there's no expectation that you're necessarily going to be out$5k 6 years in.

Why? How do they differ from ICE cars in this respect? Are the break pumps not going to wear out, or the AC system get old and die?

This is a good point, though. Do the batteries reliably last that long? I guess you got this number by assuming 100 miles driving every day, times 6 years?

A lot of people keep cars for more than 6 years, although they probably drive less than 100 miles per day. How does that affect the battery life? Will it last 12 years if I drive 50 miles a day, or do the recharges cycles themselves wear it out?

An electric car with 100k miles and a dead battery likely has a resale value of nothing - probably you even have to pay to have someone haul it away and dispose of it. Which disposal will not be cheap, what with the huge dead battery full of nasty chemicals. A new battery pack will easily cost more than the value of the car.

But my main complaint about electric cars is that so much of our electricity comes from coal anyway. And a coal-powered car is actually a step backwards from an oil-powered car, in environmental terms.

20. ### OnlyMeValued Senior Member

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Some years back I went through at least the design phase of an all electric conversion. I settled on a modified wheel motor drive, that is essentially a high power servo motor and direct drive. The system is used in some European busses. The stated life expectancy of the wheel motor was equivalent to 800,000 miles of drive time.

For an all electric model using that type of system, aside from the batteries, the only wear concerns over any realistic life expectancy of the vehicle would be maintenance issues, like breaks etc. and designed failures.

It is one of the problems with the hybrids being developed. They are essentially inline hybrid systems where the gas or diesel power plant and the electric generation plant are enclosed in a single structure. The gasoline engine will wear out within a far shorter time frame than would be the expected life cycle of the generator.

Think about it if an electric motor or generator is used at less than peak performance specifications there is little to breakdown. Most failures of such systems are due to poor heat dissipation or continued operation at maximum capacity which is also mostly a heat dissipation issue.

Yes I was just projecting a 100 mile per full charge range, over a 2000 charge life cycle. The 2000 charge life cycle assumes optimal charge and use and leaves the battery with a full charge capacity of 80%, or 80 miles. This comes both from information provided for the Li battery pack for my trike and from some of the information provided for battery life of the Nisan Leaf and Chevy Volt, however those specs seem to change over time.

It is my understanding the newer Li battery designs have no built in charge memories and that recharging at a 50% charge as compared to the recommend minimum 20% charge level does not affect the battery life. Fully discharging, to a dead battery state would adversely affect life expectancy.

Something to keep in mind is that as power generation moves to renewable sources like wind and solar, batteries that hold 80% charge even less, are still functional, for energy storage for off peak production hours. Even home solar power system are designed with battery based storage systems. An exchange and/or credit system would provided a cost offset for replacement batteries for a vehicle while being also a cost advantage for the utility. I think a system like this was proposed for electric cars in India. When the battery no longer holds sufficient charge to be useful for a vehicle, it is traded in to offset the expense of the news battery.

This raises another design issue with current designs, they are not compartmentalized in a way that optimizes swapping out individual components. Auto manufactures have practiced planned obsolescence for a good many years now. And every manufacture designs their own battery pack. This rives up initial production costs and prevents interchangeability of component parts. Not a big concern for a lead acid battery in a conventional vehicle but a big income point for an all electric, even hybrid vehicle.

21. ### KilljoyKlownWhateverValued Senior Member

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Just wanted to say this topic has turned into a real treat. I like it.

22. ### Fraggle RockerStaff Member

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24,690
No, it will happen when the generation who already does everything virtually comes into power. They're not going to spend two hours a day commuting to an office building, in order to do things they can do just as well at home in their bathrobe.

However, it will indeed require managers to actually learn how to manage. You're right that now all they do is pay people for the number of hours they spend at their desks, which means that they've trained two generations of Americans in how to look busy. That's really easy with a workstation! What they will have to do is pay people for what they accomplish.

[This will be a paradigm shift for civil service--what we call "government jobs" in the USA. Their accomplishment rate is very low; many people accomplish nothing for years on end. I hasten to add that in most cases this does not mean that they're lazy or incompetent. Government offices are full of people who are smart, well-educated, and really want to get something done. They just can't do it because the system fights them--a system of rules and procedures so old that the people who implemented them are dead, and they have a built-in mechanism for thwarting change so every new President can't turn the system upside down and make it even more chaotic than it is.]

Managers will have to learn how to give their employees measurable, achievable goals. And of course that means that their managers will have to give them measurable, achievable goals!

In case you haven't noticed, most of today's managers really have no idea what they're doing or why. So this will really revolutionize American business. Judging from its current state, it can't happen soon enough!
The company I work for has a very low paper volume. I'm even better at home. About the only piece of paper you can find on my desk is my grocery list. And that's an Excel printout.

Yeah, some day maybe I'll get one of these new doohickeys, a little computer that looks like a phone. Or maybe not, since like most people of my generation I don't even carry a cellphone because I just fuckin'-A don't always want to be reachable!

And I'll never forget my favorite line from the "Boondocks" TV show: "Nothing worth reading was ever written by a man who was typing with his thumbs."

23. ### KilljoyKlownWhateverValued Senior Member

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I've heard they are planning to put super computing power in the cloud, so that everybody will be able to afford a hand held with the power of a super computer, and the batteries should last longer because of it.

May I assume that last comment of yours was directed at text messaging. But even if you don't want to answer the phone, a text message can deliver a time critical important message from a loved one as soon as you can get to it. It only takes one such experience to make a believer out of you.