What is Charger: Definition and 107 Discussions

A battery charger, or recharger, is a device used to put energy into a secondary cell or rechargeable battery by forcing an electric current through it.
The charging protocol (how much voltage or current for how long, and what to do when charging is complete, for instance) depends on the size and type of the battery being charged. Some battery types have high tolerance for overcharging (i.e., continued charging after the battery has been fully charged) and can be recharged by connection to a constant voltage source or a constant current source, depending on battery type. Simple chargers of this type must be manually disconnected at the end of the charge cycle, and some battery types absolutely require, or may use, a timer to cut off charging current at some fixed time, approximately when charging is complete. Other battery types cannot withstand over-charging, becoming damaged (reduced capacity, reduced lifetime), over heating or even exploding.
The charger may have temperature or voltage sensing circuits and a microprocessor controller to safely adjust the charging current and voltage, determine the state of charge, and cut off at the end of charge.
A trickle charger provides a relatively small amount of current, only enough to counteract self-discharge of a battery that is idle for a long time. Some battery types cannot tolerate trickle charging of any kind; attempts to do so may result in damage. Lithium ion battery cells use a chemistry system which does not permit indefinite trickle charging.Slow battery chargers may take several hours to complete a charge. High-rate chargers may restore most capacity much faster, but high rate chargers can be more than some battery types can tolerate. Such batteries require active monitoring of the battery to protect it from overcharging. Electric vehicles ideally need high-rate chargers. For public access, installation of such chargers and the distribution support for them is an issue in the proposed adoption of electric cars.

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  1. S

    What USB adaptor is suitable for a smartwatch?

    Hello, I bought a smartwatch and it does not have a charger. The capacity battery is 230mAh. In the manual, they wrote input parameter should be 5V = 500mA. If I choose a charger with high output power (15W (5V/3A), (5V/2.4A), 20W, or 65W), will the watch's battery be damaged? Does the charger...
  2. sophiecentaur

    Electrical Improving Car Radio Reception While Charging Mobile Devices

    M y FM car radio is hopeless when my iphone is charging. The charger is cheap and cheerful and I'm sure I could do better. A low efficiency non switch mode supply would do the job. Any ideas about a make? I don't want to go down the road of chokes and tinfoil cos the car interior would look too...
  3. S

    Isolate solar charger PWM pulses

    After we got the solar array working, we made all lamps, laptop chargers, most kitchen appliances... run on 48vDC (so that we can have the inverter switched off unless we're running any 220v appliances). Then everyone in the house got a headache. We traced this down to being indoors at daytime...
  4. K

    Could a battery charger be damaged more easily than the battery / device?

    I've got an electric toothbrush which is rechargeable, it had been regularly used and charged for years until one day it didn't charge. I immediately thought that the toothbrush was failing but at the end of the day I found that it was the charging stand failing, the toothbrush was fine. But I...
  5. L

    Charging an iphone with macbook charger

    So I can charge my iphone, with the 61W macbook charger using the USB-C interface. I think the battery won't draw more effect than it needs/is dimensioned for, so this works fine. Can i use any charger with an USB-C interface to charge my iphone? or does it only work with apple products? Or...
  6. J

    Field of a "pancake" coil in QI charger

    Attached is a photo the the primary transformer coil of a QI (I believe pronounced CHEE) wireless charger, as used for charging a cell phone. I know the fields of solenoids but what would be the magnetic field structure of this. By-the-way, a similar coil was used on old AM radio sets.
  7. T

    Design of Hydropowered Turbine Propeller for Mobile Charger

    I am currently working on a project for an undergraduate course in university. My team and I have decided to make a hydropowered mobile device charger, and I am responsible for the design and modeling of the turbine propeller. This turbine will need to be able to function in low velocity streams...
  8. afternoone

    Electronics DIY a wireless charger into a book

    Check my art DIY a wireless charger into a book how it looks like after finish here is the video: DIY a wireless charger into a book the brand is Soopus-X if you ask
  9. DaveC426913

    Appliances Faulty DeWalt Battery charger for power tools

    I've replaced the charger for my DeWalt tools several times, and now I may have to go out and get a fourth one. One of them flashes a fault warning (steady slow flash), the other two do not light up at all. Now, I do not take care of my tools. All three of these chargers may have been exposed...
  10. Panagiotis Soutzis

    MATLAB How to Design a 5V/1A Charger in Simulink?

    Hello, i need help to design a simple charger of output 5V / 1A . Just to represent the charging in simulink. Anyone for help ?
  11. J

    What current would a 12 V lead-acid battery draw from a 24 V charger

    I know this is not ok but just for a few seconds or minutes and for the purposes of "boiling" the acid a little to make it even, break some sulfate deposits off the plates and recover a young battery that was neglected for a few months, what current would a 12 V / 480 A / 85 Ah lead-acid car...
  12. J

    Using 6 Diodes for a 30 Amp Battery Charger

    I was told once that two 1 amp tv type diodes parallel will not work because one will always carry the load, but I am working on a car 30 amp battery charger and it has 6 diodes 1/2" press in type all parallel same as from a 10DN series Delco alternator from the 60's where they used three...
  13. G

    Battery charger circuit fault(s)

    My cheapish 12V battery charger suffered an overcurrent, and now is not working properly. Below is a schematic of the main power side: The MOSFET M1 will not turn on, which I'll tackle later, but even with the drain bridged to source the voltages are wrong. The black, slow charge (rail at...
  14. G

    What caused the teenager to die while charging her phone in the bath?

    http://www.telegraph.co.uk/news/2017/07/11/teenager-dies-charging-phone-bath/ The poor girl got electrocuted, I assume, from the USB case being live at mains voltage. I don't understand - between you and the mains, there should be a transformer, class Y capacitor, and an optocoupler. No direct...
  15. G

    Electrocution by iPhone charger (involving a bathtub)

    This link: http://www.telegraph.co.uk/news/2017/03/17/man-died-charging-iphone-bath/ Briefly, a man was using his iPhone in the bath while he was charging it. He dropped it in and was electrocuted. How? Where did the mains reference come from - transformer? Optocoupler? Y-Class capacitor? I...
  16. G

    Why do some devices work for a short time after unplugged?

    Hi. Some laptop or mobile phone chargers still work for a couple of seconds after being unplugged. I've also seen similar behaviour with the standby lights of monitors, TVs and other devices after they are disconnected from power. Is this due to self-inductance in the transformer? If so: If...
  17. Akmalidin

    Can I Charge My Phone and Battery Pack Simultaneously with a Power Bank?

    Hello, I have built a portable power bank to charger my phone when necessary. But I have a problem with it. When I charger the power bank, it is charging only my battery pack which is NiMh, it is not charging my phone at the same time.Therefore, I want to ask ,how I can make my system , so it...
  18. E

    Mimicking a 14.4VDC Speaker Charger

    Good day Everyone, I am going camping and I am rigging up a couple small solar power setups, I have a 12V 26AH Battery with a solar panel and appropriate solar charge controller. I will use this to charge a few 5V devices(Mostly cell phones for taking pictures and videos). Anyway that setup is...
  19. P

    Battery Operated Cell Phone Charger

    Hey guys, I am building my own battery operated cell phone charger. I am pretty sure I built my circuit correctly because the outputs I am reading on my USB output port: pin 1 is 5V and on pin 4 is 0V... which are good readings (and tells me that my voltage regulator is functioning properly and...
  20. B

    Input and output voltages and amps on my laptop's charger

    The wire on the charger that came with my laptop eventually frayed, and I had to buy a new charger for my laptop. Both the new and old chargers for my laptop plug into a standard wall outlet. On the new charger, it says the following: " Input: 100-240V ~ 1.5A 50-60Hz Output: 19V --3.42A 65W...
  21. Steve619

    Building a solar phone charger

    Hello. I am building a solar phone charger and have decided to use 3 Nimh batteries, a 5/6 v solar panel, a usb 5V rectifier and also a Lipo credit card rechargeable cell. My reasoning is limited for this build as the more I read, the more conflicting info I find... (Eg, charging AA batteries...
  22. evilfreddie

    Li-Ion Battery Charger for Drill - 12V 3s Balance Charger

    Hey all I've got an old drill witch nicad batteries had died so i replaced them with 3 li ion batterys for 12v i still have the old charger plug so far I've hadto unsolder the batterys to charge them does anyone know of a 3s balance charger for lithium ion batterys asi can't find any online Tia
  23. P

    Shopping advice: Solar battery charger and power supply

    I'm sorry if this isn't the right place for a shopping question, but I'm not sure where else to go for advice. I got a https://www.amazon.com/dp/B0094KM4VK/?tag=pfamazon01-20 on sale and the unit is great, but the batteries don't hold a charge very well, especially when using rechargeables - it...
  24. Semiavas

    Class 2 battery charger as a LED power supply?

    Hello, I'm planning to light up a tile chess board with 64 LEDs (blue and white) set between the tile squares, and I was wondering if this Class 2 Battery charger output: 12VDC 900mA, would work to power 16 parallel sets of 4 LEDs + 1 ohm 1/8W resistor and a SPST toggle switch? The current...
  25. J

    I built a 3 stage PWM solar charger using an arduino

    I am an electrical engineering student. I have been on summer break for a few weeks now and I had time to work on my project. This is not a school project but something I had wanted to complete for a while. I haven’t decided what I am going to do with it yet. I just built it for the fun of it...
  26. R

    Modifying a phone charger from 5V down to 3V&4V

    Hi. I relized today i have an old charger lying around that has no use anymore, so i wanted to do a little project with it, it indicates that the input is 100V-240V~50/60Hz 0,1A and the output is: 5.0V DC 350mA. I want to add a feature to this charger, a switch, that changes the outpunt, and...
  27. T

    Charging 2 Mobile Devices from 1 Charger

    I would like to charge my śmart phone and a tablet from a single charger. The specs are as follows; Charger = 5.2 v and 2.0 amps Smart phone battery = 3.7 volts and 3300 mah Tablet battery = 3.7 volts and 4000 mah So using a Y cable, will this recharge both devices with any level of...
  28. B

    Question about 12v Solar charger?

    Hi, I recently bought a smallish 12v DC solar panel for trickle charging my jetski battery. I've had a look at the panel with a multimeter and in good sunlight it makes easy 24V but very very low current. I was wondering if I stick a 99pence buck converter on in, forcing the voltage to a max of...
  29. E

    Making a solar cell phone charger

    Good day everyone, So I have a spare solar panel that has been laying around and I want to put it to use. Its a small panel, about 8"X12". The specs read 8 Watts and 17 Volts I was thinking of maybe making a solar charger for phones and other 5VDC USB devices. I bought a 5VDC regulator kit...
  30. J

    How to charge a low amperage battery?

    I have a motorcycle battery which is 6Ah, with a maximum charging current of 0.6A/h. Is there a method of charging it whilst using a 2.7Adc (4A RMS) charger? I was thinking using resistors in parallel or series between the charger and the battery, but I am not sure exactly how.
  31. B

    Charger works with engine off in big rig but not in car

    I am a trucker. I drive a Freightliner Cascadia semi-truck. My cell phone charger will charge my cellphone with the engine turned off on my semi-truck. But the same charger will not charge up my cellphone in my car when my car's engine is turned off. Why will my charger charge up a...
  32. J

    Portable Phone Charger (Power Bank)

    I am interested in designing my own portable phone charger or power bank. I would ideally like to use a Li-Ion battery and be able to have interchangeable male connectors depending on what phone I have at the time (ie iPhone 4s, android, galaxy, etc). Can someone please provide a basic circuit...
  33. M

    Would this Battery charger work as a direct power source?

    Hello I need a source to power ADSL router when the electric power would be cut for any reason because i need to keep my laptop that i use for work connected to the internet. I found this "Anker® 2nd Gen Astro Pro2 20000mAh 4-Port Aluminum Portable External Battery Charger with 9V/12V...
  34. R

    Creating a Cell Phone Charger from Batteries: Understanding the Process

    Hi, I'm currently working on a project: I'm trying to make a cell phone charger from an Altoids tin and batteries. I know there are countless tutorials out there, but I want to understand why everything happens and how it works. I'm getting to each problem individually, so that I can find a...
  35. T

    Charge 4 AA Lithium Ion Batteries at 5V in 2 Quarters

    Hi I need a circuit to charge 4 aa lithium ion batteries. I need it to charge at 5 volts and when the batteries are done charging, the circuit cuts off. It would help a lot if I could get this in a small space around 2 quarter's. Thank You.
  36. N

    Would a battery pack phone charger case discharge your phone faster?

    So supposedly if you leave your phone plugged into a charger but the charger is not pluged into anything then it will discharge your phone faster, so if the charger cases have a charger connector constantly in your phone will it actually discharge it?
  37. Tesladude

    Why Is My MOSFET-Based Charger Only Outputting 3V Instead of 15V?

    Long story short, I have a circuit board with I programmed smart charger on it. The microcontroller is supposed to put out 5v to trigger an enhancement type n-channel mosfet which simply connects 15v to my battery. But only 3v is coming out of the mosfet. It is an irl510, what is going on?
  38. F

    Work done of charger of a battery

    NEVER MIND! I realized my question is kind of stupid. Its night here and I am kind of sleepy. :)) Homework Statement a battery of 4V is connected opposite to a battery of 2V to charge the 2V battery. assume the current running through the circuit to be 2 Ampere. What is the Work done by 1)...
  39. N

    Working of Solar charger circuit

    Hello everyone ! can you please tell me how this whole circuit is working ? specially these ones, 1.whats happening at LM317's pins(in adjust and out) ? 2. what's the purpose of zener here? 3. purpose of transistor nd how is it working ? last question! how much time it will take to...
  40. L

    Is It Possible to Charge an iPod Using a Windmill on a Car?

    I'm a high school physics student, so keep my limited knowledge in mind. Basically the other day I had the idea to create a charger for my iPod that's powered by a windmill, which I could attach to the outside of my car. I've never actually built a windmill before, but I'm pretty confident I...
  41. Q

    Shorting the Ends of a Mobile Phone Charger

    What would happen if I shorted the ends of a mobile phone charger (in both the cases when input is 110V or 220V)? I was considering using the terminals of a charger as a dc source for any experiment I might want to do at home (batteries would be too expensive), and wondered whether it was a...
  42. S

    Mylar to increase efficiency of solar battery charger?

    I just got my hands on a solar battery charger with a set of usage specifications that makes me believe it will only be useful some four days a month and will take more or less such time to charge a single set of batteries, despite promises on the contrary in the instructions. Since the case is...
  43. V

    Need help making a solar panel AA battery charger

    Hi, I'm working on a project to build a solar powered AA battery charger. This is definitely not my profession, I only have a small understanding of electrical engineering. Mostly from what I learned in high school electrical class. Here is what I'm looking to do: I want to charge 16 AA...
  44. N

    Cheap Homeade Solar Powered Phone Charger

    I would like to build a small solar powered phone charger for when I go up to camp soon, I was planning on using a solar cell and I was wondering what I need to assemble a solar powered phone charger. Can someone help?
  45. C

    Looking for tips with a wireless charger summer project

    Hey everyone! I've gotten some really good help over in the math section of physicsforums, and I was hoping to get some more of the same here in engineering. I've just finished my sophomore year in school, and I'm about to apply for the EE program at the university in spring. Anyway, I...
  46. D

    Battery Charger Considerations?

    A friend of mine lost his battery charger for his airsoft gun and he naturally comes to me for electrical help. Problem is, I'm freshmen level right now. I looked up how to hack and build a basic battery charger, my question is do the internal resistance/impedance of the batteries matter when...
  47. Tesladude

    Creating a Solar USB Charger: Troubleshooting Tips

    So I want to make a solar usb charger but am having some problems that i do not understand. I know that usb is 5v at 1 amp-ish and so I took 4 rechargable AAs and was getting just over 5v. I want to have the solar pannel charge the batteries when there is nothing being pluged into the usb...
  48. F

    Build Solar USB Charger: Voltage & Current for Rechargeable Batteries

    I want to build a usb charger that works with solar power (and later add a crank dynamo too). The photovoltaic cell will charge rechargeable batteries and they will charge the usb device, like my smartphone. The smartphone charges with 5V and 1500mAh. I'm planning to use 2 AA batteries 3.4V...
  49. J

    Electrically driven Turbo Charger

    Hi; In a regular 1900 TDI car engine,if the turbo were to be operated by an electric motor instead of by the exhaust gasses,how many HP would be the needed output of such motor in order to produce the same effect. Thks. J.D.
  50. Pengwuino

    IPod/iPad/iPants compatible charger?

    "iPod/iPad/iPants compatible" charger?? I was browsing the interwebs for some chargers for the various awesomes that happen around my house and I noticed something. I keep seeing wall chargers that are "iPad compatible" and there's all sorts of mention of compatibility. The thing is... what the...