How do you create a circuit that will disconnect the current when a lithium ion battery becomes fully charged?
465838
Well, NiCd and NiMH batteries can be charged and stop charging at full charge without the help of some device to determine if it's full. Once the NiCd and NiMH is full, the current will just pass through and waste your electricity (and if it's left charging at full charge for extended periods, it can also damage the batteries). So it doesn't actually disconnect the current. Just passes through.\n\nBut in Lithium ion batteries, you need some kind of device to determine if it's fully charged. Cellphones, PDA, and iPods kinds of turn on (like, it shows the charging display, but it's not actually on and in your normal thing) when it's plugged into a current so it can detect if it's fully charged. So basically, the device is the mini-computer that determines the charge of the battery.\n\nSo, to answer your question, don't try to create a circuit that will disconnect the current when a Lithium Ion battery becomes fully charged, unless you have the capability, materials, time, and patience to do it. And steady hands. It's really tricky to build a Lithium Ion Battery charger.\n\nPS Penguins!!!
587056
Unless your batteries are used in a continuous timed manner such as might be with a hand held radio in an industrial setting, where the radios were charged at the end of every work shift, NiCad memory isn't the problem it is reputed to be. \n\nI have used a 50 ohm, 20 watt resistor placed across the small battery's poles to discharge them with success.\n\nHowever it should be noted that a TOTALLY discharged NiCad battery is suseptible to reverse charging if placed incorrectly in the charger. The original "positive" pole will become the "negative" and vise versa. Not a good idea for NiCads.\n\nProbably best to use the "discharge" function of your charger despte the time required, and not take chances, eh? \n\nAnother idea would be to replace them with Lithium Ion (Lithium) batteries which are not suseptible to the "memory" effect. Effective, but expensive.\n\nOuzinki\n\n(36 years as an electronics technician)
1113235
Could be a dead battery. The lifetime of lithium ion batteries varies with temperature, number of recharge/discharge cycles and percent of discharge and percent of recharge. Complete, 100% recharges actually shorten the lifetime, but, complete discharges are worse. Partial discharges and partial recharges can lengthen the usable life. The lower the storage temperature, the better, but, DO NOT freeze. High heat, such as in a vehicle or storage building in summer drastically shortens the expected lifetime. A lithium ion battery's normal lifetime is about 3, maybe 4 yrs. Best longtime storage is at 40ish degrees F with about 40% charge. ( just the battery, not the device )
509223
Something else in the pocket made contact with both terminals, causing the battery to pass current and generating heat.  I did this once by tossing a 9V that I thought was discharged into my pants pocket where I have my office keys.  The keys completed the circuit from the positive to the negative terminals, and I shortly noticed the heat.
312735
Try a damping circuit.
167412
My suggestion would be to use a d.c. motor .  Incorporate the following : A D.C. motor, 2 momentary contact up/down switch, a reversing relay that would switch positive and negative when switching from up to down . Associated micro switches and ice cube relays to sense position and stop motor when destination is reached. Some form of safety clutch,light curtain etc. And a rectifier to convert house hold alternating current to D.C. . An alternative would be a reversing A.C. motor and associated similar controls less rectifier. Similar installation difficulty , my decision a/c vs d/c would be based on price and availability.
468097
Lithium cells are becoming an increasingly important part of portable power sources due to their high energy density and low weight. To fulfill their full potential, lithium cells must overcome several limitations. The most significant of these limitations is the formation of ion gradients in the cell’s electrolyte. Such gradients impede the amount of current that the cell can produce. Overcoming this limitation will allow lithium cells to output an increased amount of current.\n\nBased on earlier studies that have been conducted on lithium / silver salt cells, it was observed that current output depended on electrolyte concentration, viscosity, and the particular anion of the silver salt. From reading and consultation, I have come to focus subsequent studies on the effect of these variables on the formation of ion gradients in these cells as an underlying factor effecting the current output.
231919
Cool question.\n\nTake a sheet of aluminum foil and cut it into a thin strip.\n\nTape the metal tip of the bulb to the tip of a flashlight D battery. \n\nWrap one strip of foil around the screw part of the bulb.\n\nNow touch the foil to the bottom of the battery.\n\nThis is a simple circuit!
174862
Run the positive wire from the two lights together, and tap off that connection to one side of the switch, from the other post on the switch, run to a fuse and then on to a positive connection ie: your battery. The other wire(negitive) wire from the lamps run to the ground, or frame of the vehicle.
358273
http://www.howstuffworks.com/battery.htm
1078584
There are some solution available at http://www.batteryspace.com/index.asp?PageAction=VIEWCATS&Category=885
743213
Hi there...\n\nProfessional battery equipment is needed to recondition any battery, and the LITHIUM ION are the most deadly .... \nIn battery shops accross the country, the service technicians will generally not TOUCH a lithium Ion. \n Where I am located, there is a shop, and they tell me that they would have to install a fire-brick fume-hood, with explosion proof shielding, and other specialized bomb disposal stuff, before they could work on the Lithium ion batteries.\n As one other answer stated, the batteries, despite being " no memory " unlike Nickle Cadmium batteries, which "remember" being both not fully charged, and not being fully drained, the Li Ion batteries just plain die. Another answer gives you a link to NI-Cads, which is useless. The charging and cycling of Li-Ion and Ni-Cad are completely different. With old Ni-cads, you can use an ordinary capacitor to zap the batteries back to life, once. The professionals use very sophisticated machinery to revitalize older Ni-Cads. Nickle Metal Hydride are in the middle of the pack, with a different set of characteristics.\n  YOUR batteries are the worst.\n\nIf over heated, they will bloat, crack, and gas will escape in a foot long flame  that will cut through solid bone.. ie ... it can ampute an arm or leg if you happen to get in the way. There are reports around the world of people being " burned" and in the hospital, from Cell phone Li-Ion batteries. Cell phone Li-Ion batteries that are bloated are capable of cutting through the side of an airplane, including the hydraulics, frames, and wiring....\n\nUnfortuneately, in your case, you are forced to just replace the battery pack... do not play with it!\n\nIn the future, you might want to charge the battery as often as you can - the battery WILL remember slowly dying by lack of use. If it is always kept charged, it will last longer. People are lazy and don't bother to charge batteries until they " have to ", and this will shorten the life of any battery.\n\nGood luck
994883
That is exactly what happened to mine.  It was supposed to be a "memory - free" battery, but.....\nOnce it's fully charged, unplug it and let it drain completely before you charge it again.  I left mine plugged in and eventually it wouldn't hold a charge at all, and it was only two years old.
495107
Standard AAA lithium rechargable batteries require specific chargers to get maximum life from the battery.  "Trickle" (slow charging) is always safer, but you need to have the right terminal voltage to fully charge (but not over-charge) the battery.\n\nThe safest way is to use the right charger, or, look up the battery properties from the manufacturer's website.  For example, if the battery is a 1.5V battery, you can charge with a 1.6V charger (1.6V is needed to overcome internal battery resistance), while measuring the charging current.  Some batteries charge with constant current for part of the charging cycle, switching to constant voltage for the final part.  The manufacturer can tell you what is the best cycle.\n\nWhat you don't want to do is to charge a battery with a nominal 1.2V rating with a 1.6V charger at high current.  The battery will heat up and possibly explode, so make sure if you use a different charger that the voltage is within about 0.1V and the current isn't too high.
130064
CONCLUSION\n\nIn the course of these experiments, you have become familiar with various concepts such as the conductivity of solutions by way of dissolved ions. you have seen redox reactions at work, and that they can be reversed by running current through the circuit. You have learned to measure potentials of reduction of various materials and to predict the voltage generated by a battery when you know it's material components. You can build a working battery from various materials, including lemons, tomatoes, potatoes, almost any fruit or vegetable. Up until now, batteries may have seemed mysterious, but now we are among the few that have a working knowledge of how and why they work. You can amaze your friends by building a battery out of almost anything, but more important than this, now the study and mastery of this subject will be easier and more meaningful\n\nsee the full answer here:
342190
If you can get your hands on a solution of silver nitrate, it should be pretty easy.\n\nYou'll need a battery (9 volt should do it) and two lengths of wire.  Run one wire from the positive terminal of the battery and attach it to a silver electrode (available in science shops) or any piece of silver.  If you can't get the silver electrode, just use the copper wire.  This will plate some of the copper onto the ring, though.  Attach the other wire to the ring and to the negative battery terminal.  Lower the ring and the silver electrode into the silver nitrate solution (without letting them touch) and wait.\n\nThe positive silver ions in the solution will be attracted to the negative ring and should plate the ring nicely.
276822
I recently read about new power strips that cut even standby power to equipment that are plugged into them. For example, your computer and printer still draw a current even if shut off. this tricle can add up over the course of a year. These power strips cut off that tricle until the moment the unit is roused from standby.\n\nThis was in a pretty good article in this month's Kiplinger's Personal Finance magazine.