Electrical enginnering people and hardware hacking people. Please help me figure this one out.  Charging Lithium Ion batteries is a more delicate process that charging NiCd and NiMH batteries.  I was told by the local Radio Shack walking book of knowledge that charging Lithium ion batteries requires more control as the lithium ion cells may be damaged easily if the current is not disconnected at the final stages of a full charge. He suggested that I not try to charge lithium ion batteries with a direct current.  He stated that there needs to be a circuit like that which is present in a cellphone, pda, or ipod that will limit current as the battery reaches it's charge. What do you know about this?
210815
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!!!
621136
The above answers about using a voltage regulator sound ok.  Just make sure to check out the regulator's data sheet so that it can safely regulate what DC voltage you are giving it (though with this 12V case you shouldn't have a problem).\n\nAlso, when a battery is rated at 12V, 30A the battery doesn't necessarily output 30A at all times; that is just a full load rating given for safety reasons (don't want to overload the battery).  The battery is a constant voltage source so you can certainly have a load that pulls much less than 30A.\n\nWidth of wire?  You shouldn't be too concerned with this at these low voltages.  Just use breadboard type wire (around 22 AWG I believe).\n\nAlso, one final comment from me... why use a car battery when you can use a more convenient source of DC voltage?  If you want something that can conveniently power your IC's try one of those nifty AC/DC plugs that charge cell phones and the like.  They are rated in various output voltages and can surely supply all the current your IC's will need.  Just cut off the DC plug end and strip the wire.  Boom, now you have DC voltage for your breadboard supply terminals or whatever.
482799
carbon has no free electrons available\nso it cannot conduct electricitys\nin case of germanium and si they have d orbits in the outer shell and they have greater mobility
243543
well, i think it is... but just in case, while its charging, move the click wheel around until the screen comes up. then at the upper right hand corner where it tells u how much battery u have left, there should be a picture of a lightning bolt which means its charging. if its a picture of a plug, it means that its done charging.
17386
many chemical reactions happen at the interface between different phases of solid, liquid, or gas.  the reaction rate is often limited by the surface area - so to increase the rate, you can increase the surface area. \n\n an example of this is in batteries - the ion-exchange process that batteries use happens at the surface of the electrode, where the solid metal electrode exchanges ions with the electrolyte solution.  lots of newer batteries use highly-porous materials for the electrode - all those little pores can increase the surface area by several orders of magnitude, allowing the reaction to run much faster.\n\nso, if you know how to drive it out of the rocks, then you're in good shape.  a simple answer to increase the rate is to crush the rocks into small grains.  this will allow for a much greater surface area, so water diffusing through the rock will make it to the surface sooner.\n\nalso, many reaction rates are sped up by increased temperature.  so you could build a fire and heat the rocks.  an increase in temperature means, on the molecular scale, that the atoms are moving faster - this means your reaction goes faster - and the water comes out faster.
354318
you're well insulated.  Therefore when you collect charge from moving around, you don't lose it very easily.  Then you touch something, a door, or metal that is a very good conductor....you lose the charge in the form of static electricity.  walking around on plastics will do the trick...turf, trampolenes, synthetic carpeting.  As they are very willing to give you charge that they have built up, and if you're well insulated...you start collecting it.
56229
Salt water works better because it's a better conductor of electricity as opposed to just tap water.  In salt water, you have a solution of both Cl- and Na+ floating about creating a means of transferring electricity (electolytes).  So, instead of a saltbridge to provide the transfer of ions, all the ions needed are right there, which will quickly drain the battery.  Think of it as a short circuit - you have a large current because the path of resistance from the cathode to the anode is nothing.  Plus, there's plenty of ions to provide that means of conduction.
332910
The terms refer to current direction.\n\nDC (direct current) only travels in one direction.\nAnything operating from a battery  (flashlight, car starter, disc man) is running on DC current.\n\nAC (alternating current) changes direction at a regular frequency. In North America, that's 60 times a second, or 60 hertz. Electrical outlets supply AC current for most household appliances.
195921
More than likely DC.  By using direct current you are always keeping one end the anode and the other the cathode, one side always is "giving" and the other end always "recieving."  DC systems have a tendancy to corrode one end and slowly eat away at it.
591095
When you use a computer, there should not be any electrical charge because the computer is grounded at the power supply within the computer cabinet.  If you do get a charge built up, you have to be "ungrounded" - no connected to metal. The computer is not properly connected to mains power.  You can discharge by touching metal that is connected to earth.  You can not discharge this energy by herbs, diet, fruit or vegetables.
10318
NiCads in general electronic applications are typically designed to NOT get hot, since the heat destroys the NiCad battery, can damage electronics and causes lawsuits when users get burned from the hot battery.  Some devices like radio-controlled cars are high-drain applications that generate a lot of heat, so the batteries for these devices are designed for their specific use.\n\nBatteries get hot when they charge due to the high current going into them.  The faster they charge, typically the hotter they get.  When the battery discharges during use, the same thing happens, the battery gets hotter as more current is drawn from the battery.  \n\nWithout knowing anything else, my guess is that high current draw from the battery cells is causing them to heat up.  This can be due to a defective battery, a battery not designed for the way you are using it or your modification damaged the battery or is otherwise causing excessive current drain.\n\nAlso, increasing the supply voltage can drive more current through the device, so it may just be that the higher voltage is drawing more current.\n\nI’m not sure how the device is shutting down, so I can’t say why it’s doing that.  Note that the voltage at which a device stops working is the voltage seen by the device itself.  If you remove the battery from the device and measure the voltage, you will get a different voltage than if you measure the voltage at the precise moment the device shuts down.  This is especially true for high current drain applications, which appears to be what’s happening with your batteries. \n\nPlacing the NiCad’s in the freezer won't help.  They’ll have to warm up to work properly anyway.
611436
Pickles conduct electricity (and will glow like a light bulb when a current passes through them!) but I remember seeing on Mythbusters a method of creating a battery that was used in the ancient times and is relatively simple to make.\n\nEdit to your add. details: perhaps if you were to give a complete idea as to what you were doing that involves drawing electricity, magnets, and having to function as a remote control, some of us might be able to point in the right direction. Myself, I'm not sure exactly what you need.
516281
1. no a 7 amps charger cannot harm u'r notebook, neither can a 700 amps charger, provided the voltage rating is correct & it's a smps\n2. i will never recommend a charger from a different supplier than notebook manufacturer, reason being a. the battery charging circuit is a bit tricky, an auto cut-off switch mechanism for supervision / regulation charge: boost / trickle / off states b. the mating pin connecting notebook can make a loose connection, causing localised heating / sparking\n> if at all u buy different, only supplier i know of is targus\nhttp://www.targus.com/us/powerstore.asp\nfill in relevant details & after a few steps, offer comes up
206258
First you can calculate the quantity of electricity used to charge the battery using the equation:\n\nQ = It\n\nwhere\nQ = charge in Coulombs (C)\nI = current in Amps (A)\nt = time in seconds (s)\n\nIn the above question then\n\nQ = 0.5 x 100 x60 = 3,000 C\n\nNow the oxidation state of the Ni in Ni(OH)2 is 2+, while the oxidation state of Ni in NiO(OH)2 is 4+, so the change is 2+.\n\nFaraday's constant = 96,500 Cmol-1 so \nthe moles of electrons available = 3000/96500 = 0.03109 \n\nHowever, 2 moles of electrons are required to oxidise 1 mol of Ni(OH)2 therefore moles of Ni(OH)2 that can be oxidised is 0.03109/2 = 0.015545. \n\nLastly, we can now convert the moles of Ni(OH)2 to grams by multiplying by its formula mass, which is 92.708 gmol-1, ie\n0.015545 x 92.708 = 1.44 g.
9340
You are on the right track. It relies on inductive charging:\n<quote>\nIf you own an electric toothbrush, there's a good chance that it has a completely sealed toothbrush unit. The toothbrush rests on the charger without any metal contacts to connect the toothbrush to the base. This has the great advantage of allowing the toothbrush to be completely sealed so that water cannot enter through exposed contacts. It also avoids any problems with water getting into the contacts and shorting out the charger.\n\nThis sort of sealed arrangement is called inductive charging. Essentially, the toothbrush and the base form a two-part transformer, with the base having one part of the transformer and the toothbrush having the other. When you slide the toothbrush onto the base, the complete transformer is created and charge can flow.\n\nThe base contains one of the coils and the metal bar. The toothbrush contains the second coil. When you drop the toothbrush onto the base, you create the complete transformer!\n</quote>
344263
An idea would be to use a relay circuit to control the operation of the charger. The voltage out of the battery could be divided so as to latch a "normally off" relay to keep the charger off. The resistance of this circuit would be such that it would not excessively drain the battery. Once the relay is unlatched, the charger would come on.\n\nNow the difficult part - the voltage applied to "charge" the battery would have to be in excess of the "high" voltage in your range. A suggestion would be to use a timer to then cycle off the relay.\n\nThere are commercially available products that already perform this function, if I am not mistaken.
610930
I once read about a device with which reconditioning may be achieved 90% of the time on some types of batteries by applying a very brief, high voltage pulse (kinda like a camera's flash system) across the terminals of individual rechargeable cells.  I tried an improvised version of it with NiCD and sealed lead batteries, and it seemed to work most of the time.  I couldn't find plans for the device when I searched just now, though, so I can't really tell you more than that.  Unless you're knowledgeable in the field of electronics, I suggest you just get another battery because the method of recycling I just described may be dangerous.