how to know if a battery is charging? Answered

I want to know if my lead acidic battery is charging.can i use a volt meter to know that ?and how?

Asked by tarz_00 7 years ago


getting started

Hi,every body its my first post here . i like this site a lot .i want to say that i have to do a project soon but i don't know what to do am good at programming with microcontroller  but  i was surpresid that no one here use it i mean you use ready things and hacked ones. could any one help me to choose a good project i want also to ask about the charging .if i want to make a charger for many things i saw some project in this site from usb port to charge a mobile you calculate the voltage but the current>???? i mean this will not burn the mobile or anything how do you ensure that the current is suitable? i want also to ask about the solar cell?how we can create it from scratch or where can i find a ready one?if i don't want to buy it thanx sorry about my bad english

Posted by eng_mai 8 years ago


How to make multi mobile charging box?

How to make a simple multi mobile charging box? this charging boxes are mainly used on airports. that charging box should be simple and innovative.it should have different usp

Asked by snehal mane 8 years ago


Casio Commando Charging Dock

Has anyone built a Casio Commando Dock?

Posted by Builderdude95 5 years ago



Charging Circuit

I was wondering if anyone had any ideas on how to make a circuit so that I could charge a battery, but that I can also power an amplifier when the battery is not charging. Currently I have a switch that switches between a charging circuit and powering the amplifier, but I was looking for a way to do this without having a switch that I have to control

Posted by Fozzibehr 4 years ago


How exact ( +/- volts/amps) do you need to be when charging a laptop? Answered

 It seems that most laptops charge at around 19volts  (+/- 2) at around 3 amps. Can you charge a laptop at slightly over or slightly under its' charging voltage/amperage? I'm trying to make a "universal" solar charger. If not, why? I'm trying to make a solar panel that will charge a laptop. What I need to know is if it's ok for a laptop to charge at an amperage slightly over what its' charging cord is rated for (the panel would be directly wired into the laptop, bypassing the charging cord)

Asked by nepheron 8 years ago


what is the best way to make an induction charging system?

Using Neodymium magnets on the spokes of a bicycle rim, and coil around both forks.

Asked by Alanclark1966 5 years ago



Would battery charge at low voltage input from the charger?

Hi everyone, I have solar charger rated at 9volts 1A (I was able to obtain this measurement no problem), which is supposed to charge my 6volts battery. But I found out that the output voltage of my charge controller is 0.67volts and current is at 0.99mA but my battery is rated at 6v/4.5Ah. Would the low voltage output from my charge controller able to charge my battery? I am greatly confused why is the charge controller output of 0.67volts only, I know there is something wrong with this but I don't know what. Please assist me your help is highly appreciated. Thanks

Asked by mitchiko 6 years ago


hey how do i charge a capacitor without the chip from the disposable cam?

Ive recently went out to my local electrical store and bought me a capacitor along with a 4 slot AA batt holder and 9V batt holder but i cant seem to find a simple way of charging my cap. without a dissposable camera chip any ideas on how i can charge it without a chip would be good (diagrams would be appreciated to if u have some )

Asked by LILhazY 8 years ago


How do you know if a capacitor is finished charging to its full potential capacidence?

How do you know if a capacitor is finished charging to its full potential? Also if you were to have a group of capacitors linked together in a series or parallel fashion how could you determine whether or not the capacitors were charged completely? I am mainly referring to polarized capacitors. 

Asked by Dr. Kreap 5 years ago


Any objections to my battery charging solution? Answered

I bought some cheap 360 battery packs on the internet and big surprise they don't work.  The problem is that the built in charging circuit charges the packs to around 2.26v when my controller wont turn on until closer to 2.5v.  My idea is to use the indicating LED (that came as part of the pack) that has a forward voltage of around 2v to drop the 5v charging voltage down to 3v and charge the packs to that voltage.  Theoretically when the packs reach 3v the LED will not be able to sustain the forward voltage and will turn off stopping current flow to the batteries and thus stop charging.  I have a lot of knowledge about electronics, however my knowledge of batteries and their sensitivities is just about nill so I thought I'd ask here before I rig this together and get an idea of the likelihood of the batteries blowing up.  I've attached an image of the proposed circuit any knowledge would be greatly appreciated.

Asked by double_g 5 years ago


Solar power & battery? Answered

Hi everyone, I would like like to power a circuit that requires 6v from a battery charged by a solar cell. Could someone recommend a battery & cell specs? Would like the circuit to run at night for at least 3 hours. Battery needs to be quite small. I've picked Powerfilm solar cells, just need to know what voltage & amperage to use for a small 6v rechargeable battery. Thanks! 

Asked by BlondeJamesDean 3 years ago


what do you use to protect your rechargeable batteries while charging?

I got this off ebay (see attached image).  But it just flashes extremely fast between red and blue when charged (which is obnoxious since I can see it - you would not want this charging in your room at night, it's like a crazy strobe).  Another from a different seller just lights both red and blue at the same time.  Does anybody have other suggestions for what to use?  I don't need it to have lights.  Thanks.

Posted by aliasjanedoe 2 years ago


Charging a valve regulated lead acid battery?

A while ago (a few months maybe?) I bought a cheap robot vacuum cleaner from a car boot sale. I decided to take it apart as it was pretty useless as a vacuum cleaner. When I took it apart I kept the battery and the charging plug (wall wart) together. Now I want to use the battery but I am not sure how to connect it to the charger. (I tested the battery and it still works.) The battery is a 6V 2.8Ah valve regulated sealed lead acid battery. On the front of the battery it says it needs a constant voltage charge of 7.25-7.45V and less that 0.84A.  The plug that came with it is a 7.5V 600mA wall wart.  I have a vague recollection of how it was connected up. I remember that there was a diode in the mix. The positive terminal was connected to a switch and then the main control board. The negative terminal connects to the main control board and there is also a small wire that was connected to something else. I would like to know how to connect this up in such a way that is safe for charging the battery?

Asked by dracorabbid 2 years ago


design for a battery charging circuit using solar panel?

I am using a 10-w solar panel for charging battery- 4v, 6ah(3 nos 4V, 2ah battery in parallel). This is used for a GPS tracker mounted on a roof top of loco wagon . usage is 24x7x365 . i have found that gps tracker is consuming about 150ma, 4v. But after 1 to 1.5 days of usage the battery discharges and tracker stops working. one more thing the sunshine availability is approx-2-3 hrs /day. the loco wagon is standing in bright sunshine for atleast 2-3 hrs in bright sunshine everyday. where i am wrong? thanks in advace

Asked by bipin786 2 years ago


Will 22 volt solar panel hurt my marine 12volt battery?

 I bought a small solar panel to charge a marine 12volt battery, but when I checked the voltage of the panel in the sun  it read 21 - 24 volts - will that hurt my battery?

Asked by mtlt 8 years ago


Charging camera flash capacitors from mains supply

Hi everyone, I have a quick question about charging some capacitors.  I'm trying to make a very simple ignition system using capacitors from disposable camera flash circuits.  I'm planning on using maybe 5 or so.  They are rated at 330V and 120uF.  If I were to hook them up in parallel, so that i have a total of ~600uF, could I use a full-wave bridge recifier diode to turn the AC into DC and simply charge it like that without anything else in the circuit.  I don't know how to explain this very well so I attatched a schematic so you can see what I'm talking about.  Any help is much appreciated.. P.S. Ignore the fact that the full-wave rectifier looks messed up, Circuitlab.com doesn't have a f-w r symbol.  Thanks again!

Posted by BCSTechie 5 years ago


wireless charging coil size

So I bought one of these to play with: http://www.ebay.com/itm/130935883579 The transmitter board always gets really hot and smells faintly of something burning.  Is this normal?  Should I use some type of heat sink? Anyway, I discovered that you can add another coil of the same-ish size to the transmitter, and both coils will work.  However, if I remove the coil and add a single coil twice the size, it does not work.  I'm curious as to why.  What determines how large the coil can be? 

Posted by aliasjanedoe 4 years ago


Do I "Have to" use an expensive li-ion charger for li-ion battery packs?

Overview I am building a 7.4v Li-ion battery pack (7200 mAh) with a PCM of course and i usually use my li-ion / liPo charger but i was curoious if their was another way.  Details this battery pack will be installed in a portable gaming device and i want it to have its own wall charger. But i dont want it to take 6 hours. Ideas I want it to be reliable and I want it to charge fast. Most li-ion wall charger units for 7.4v only charge at 1.2A max, and charge at up to 8.4V. (And are like $25+) PCM can handle much higher, up to 8A rate Batteries are Rated up to 3.5A rate Ultimate question If I purchased 3 regular everday wall chargers, rated at 7.5V @1A (for $5 ea) and ran them in parrallel in a nice  enclosure running one charging plug, (hypothetically it "should" rate; input: 120V, output: 7.5V @3A).  Could i use this to charge the for-mentioned Li-ion 7.4V 6400mAh battery pack in just over or around 2 hours???? Or is this not feesable for some other reaon???

Asked by supramp 6 years ago


easy recharging method for child's toy

I want to use a rechargeable battery inside a toy, and I don't want to remove the battery for charging.  I'm looking for a simple and safe method for charging that a young child can do by themself.  Here are some thoughts I've had: wireless (such as with a qi pad) = Is there any way to actually keep this from getting hot?  I'm assuming the base would be always on, and the toy would be left on it all night or longer. solar = This requires a light or the sun to charge.  I'm considering putting the solar cell in the bottom of the toy and making a light base that it could be placed on, but I'd need some type of sensor or switch so it only lights when the toy is on it. metal contact pads = This would be easier than a plug since you'd only need to set the toy down, but can it be done safely?   Anybody have suggestions?  Thanks.

Posted by aliasjanedoe 2 years ago


solar panels questions

In the quest to turn my garage 'green' I started with a purchase of a Sunforce 60 watt solar panel charging kit. I already own a 12v 15amp charge controller that I bought from Green Energies. The Green Energies controller is bigger than the kit supplied so I'm currently using this one. My questions; The Green Energies charge controller is supposed to have a blocking diode in it. When I put my volt meter on the leads going back to the panels (panels dis-connected, controller still hooked to battery) I'm getting approximately 10 volts. Should there be any reading at all? I went out this rainy morning to see if there was any power coming from my panels. To my surprise I read 8-10 volts (depending on cloud cover). This leads to my next question. It is worth adding a boost converter? I suspect the amperage would only be that of the incoming voltage, not what it is boosted up to.. Close? If my guess is correct, my 5amp (system at full power, rated at 24vdc), would only be about 1.6- 2 amps @ 8- 10 vdc. I also suspect the controller is stealing some amperage. 0.5 amps??? That should leave me with at least 1 amp coming in and giving me a 10 amp day. Not bad for a rainy day. Right, wrong or hopefully close? I'm not seeing my battery come up to full charge. I'm using a marine deep cell acid battery from my boat. Every 5 years I replace it to insure the boat will start as needed. Paddling that craft back to shore is not an option. One reason could be the fact of the battery being 5 years old and it will never get back to full. Second I believe would be the draw going back to the panels at night. Will the panels draw power?

Posted by olddawg 9 years ago


Where could I buy a 15 or 20 watt amorphous solar panel in Canada? Preferably weather resistant and not too large.

I want to create a charging system for a small 12V deep cycle battery. I want to have the solar panel on top, sheltering a battery box inside a hinged four sided box underneath. Because battery boxes are made for large car batteries, there should be enough room inside the battery box for a voltage regulator and a 12v cigarette lighter like outlet on the battery box itself. I would like this to produce enough power to charge the battery during the day and at the same time, run a thermoelectric cooler, which consists of a heat sink and 4.56 W 0.38A 12V fan all day. I'm also thinking of finding a thermostat of some sort to shut the fan off at a certain in cooler or outdoor temperature. I just have some questions. 1) Where could I buy a 15 or 20 watt amorphous solar panel in Canada? Preferably weather resistant and not too large; and 2)Does this seem like it would work? I'm not that good at electrical math; and 3) Where could I find a thermostat that works on DC, and does the whole thing have to be cold, or just the probe? 

Asked by btarry 8 years ago


Solar Charger?

Hello, I am looking to build a solar charger in a 4x3x1.6 inch (or smaller) box to be as portable as possible. My only problem is, I would like to mount the solar cell on the box. However, all solar cells are far too large to fit this box, I plan to use a rechargeable 9v battery for power storage. I was wondering if I can use a 6v solar cell, and still use a standard LM7805 5v Voltage Regulator to drop 6v to 5v, or if someone could find a 2.5x3.5 inch solar cell (9v) online somewhere (for cheap) that would really help (I've looked everywhere...) Thanks.

Asked by Tuckoguy 3 years ago


why do all batteries require different charging? Answered

I mean like the difference between nimh, lead-acid, lithium-ion, and recently even alkaline. how do they each charge, and why is there a danger of exploding batteries (like lithium-ion) when charged the wrong way. is it like charging in fast on/off cycles, high volt low amp (or the other way around) or messing with anything else?

Asked by godofal 8 years ago


Dynamo charging charging circuit for AA NiCd/NiMh? Answered

I've just got hold of a Union 6V 3W dynamo with lights. I'd like to charge 4/5/6 x AA batteries during the day then switch to the batteries for the lights at night. I'm switching out the old bulbs for LEDs. Any pointers or relevant 'ibles would be great. Thanks in advance people.

Asked by ZdEEvO 9 years ago


charge 4.8V NiMH battery from computer's usb port

Hi I've a 4.8V 180mA NiMH battery i used to charge it with a 6V adapter but now it is broken can i charge with a usb port with directly hooking + terminal of battery to +V of usb and - with -V or do i need a specific circuit

Posted by alex12349 7 years ago


wiring a USB connection for charging only to a PC power supply

I want to wire a usb mini hup for charging only of USB devices such as phone, ipod etc to a PC power supply. can I just connect a USB hub to the +5 output of the PS (red) and to ground (black) and safely charge my USB devices?

Posted by jpratt2 6 years ago


Solar USB charger

Setup: 330mAh@6V solar panel charging 4xAA Nimh batteries (series connected). Iphone is connected to the batteries. Can I simultaneous charge of nizn battery and iphone? what is the direct source of power charging the iphone? Do the batteries act as voltage regulator??  Any ideas to prevent iphone from drawing more then 500mah?? Thanks, Huzefa

Posted by huzefa 7 years ago


USB Charging Circuit for 3x 3.1V Lithium Batteries

I am trying to make reliable charging circuit using 5V(USB) as source. With it I aim to charge 3 Li-Ion batteries - small coin batteries(MS621FE, datasheet). How can I make such a circuit with:  - light indication (LED)  while charging  - light indication (LED) for fully charged that stops the first LED  - protection against overcharge There are a lot topics covering similar circuits but all of them are at least for 3.7V batteries which is dangerous for such a small battery (suggested charging voltage between 2.8V and 3.3V). Does anyone have any idea how to make such a circuit?

Asked by UnitedMind 2 years ago


Charging A car battery with a PSU's 3.3 and -12 rails? Answered

Hello guys, is it safe for my car battery to charge it with a computer psu between the +3.3 (15 amps) and -12 (0.5 amps) rails, the multimeter reads a voltage of 15.2 between them, Thanks

Asked by Ninjabdou 3 years ago


how to connect camera charging circuits together? Answered

I have three camera charging circuits, how can i connect the outputs in series while connecting them all to one 3v battery pack in which they would be connected in parallel? this is for use in a coil gun.

Asked by Hav0c 7 years ago


Please give me a simple schematic for charging a HV capacitor for a coilgun

In India you don't get disposable cameras. Could you please give me a simple schematic for charging HV capacitors. I really wanna make a coilgun. THANKS IN ADVANCE!!

Asked by Jayvis Vineet Gonsalves 8 years ago


Using and charging at the same time?

Here is what i am trying to archive: 3 LED's to run off a small rechargeable battery or USB. It should also run off USB while recharging the battery.  Lake a wireless headset.  Thanks.

Posted by Squashie 3 years ago


Can you run loads off the battery at the same time you are charging?

I have a small wind turbine which I use to charge a 5 amphour sla battery.  I plan to charge it using an anyvolt micro set to 13.5 volts.  I don't have a charge controller.  For the present I plan to cut charger power manually.   If I am pumping 13.5 volts into the battery, then what happens to electronics designed to run on 12 volts if I run them in the circuit.  How do I charge the battery at 13.5v and run 12v devices off it at the same time?

Asked by Noblenutria 7 years ago


How can i charge a laptop battery without the laptop?

Hey! I have a project that requires a 11 v battery pack. I found that one of my laptops have just that and i want to be able to charge it without the laptop. How can i achieve this ? Here is a pinout of the connector http://allpinouts.org/pinouts/connectors/power_supply/dell-d500-d600-battery/

Posted by ddaemi 1 year ago


Can you charge and use batteries, from a solar system, at the same time? Answered

I am planning on making a solar system to power some things, and I was wondering if the batteries could  charge while they are being used.  Or will I have to turn off the panel while using the power from the batteries.  From the research that I have done it looks like you can. Thanks in Advance! AI

Asked by JaredsProjects 8 years ago


How to charge a 2 liter pop bottle leyden jar with a DC power supply?

Okay. So I am having some difficulty with somthing that should be simple. Leyden jars. I know that you can charge them using static electricity, but I need to know exactly how many volts are being pumped into this thing for a physics project. Because of this necessary knowledge I require, I have been trying to charge it by connecting pos and neg to it but that does nothing..... Any help how I would be able to do this would be great. Thanks 

Asked by VelcroLeaf 5 years ago


Charging Multiple NiMH

I'm modding something (secret, Instructable later) and there's going to be some integrated NiMH batteries to replace the one 1.5 AA battery that the device use to use. Due to funky space constrictions, I'll be using 7 tiny 320mAh 1.2V NiMH coin cells in parallel (to get a decent amount of maH). How hard is it to charge a bunch of batteries like this? Could I get a chip from a place like Maxim or TI? All of their chips require the batteries to be in series... Thankyou!

Posted by guyfrom7up 9 years ago


Upgrading the Charging Capabilities of an Android

I would like to know how difficult it would be to swap out the charging port on an S4 for the new hyper charging ports on the new Droid Turbo. I know there is not a lot of free space with in the cell for mods. And I am assuming that the hyper charger is smaller. That being said the tools for a repair swap out do not seem that difficult to master. What else would be needed to make this project successful, a power converter? Basically I want to see if its possible to take the outdated cells people would normally throw away or trade and mod them into something of desire for a cheaper price. Thank you for your time Instructable Community 

Posted by Ragestine 3 years ago


Arduino with solar panel

How can I charge 12V Li-ion or lead acid batteries using a solar panel? I also wish to interface the three, i.e. the Arduino, the solar panel and the battery, together so that the Arduino is basically driven by the battery but as the battery discharges, the solar panel would charge it. What circuitry do I need? Also tell the specifications of the solar panel.

Posted by DeepayanB2 1 year ago


how could i charge my sony ericsson with a usb connection to phone and connecting it to a regular home charger?

I am unable to find a sony ericsson k850i charger, i've been to almost every single store that sells this particular charger.  It was either they don't carry them no more or they just don't have it in stock.  I'm really need in charging my cell phone.  I have a usb cord for the phone but it takes forever to charge my phone.  So i thought of cutting then end of the usb cord that connects to the phone and connect it to a regular sony ericsson charger.  There is one problem the usb cord has 4 different colors red, black, green, and white.  The home charger has the regular basic color black and red.  I can't figure what the green and white wires are for and if i need to connect them to the red and black wires as well in order for my phone to charge without causing damage.  So, how would i go on putting the wires together for my phone to charge like a normal charger by using a usb end cord?

Asked by kulit21 8 years ago


how to use piezo electric transducer for power generation ?

We plan to do a project using a piezo electric transducer to generate a power to charge  a cell phone while walking so need a idea . 

Asked by sathishkumard 5 years ago


i have a battery just say 1 volt 1000 mAh and charge it with another battery 2 volt 1000 mAh how long will it take? Answered

How many mA go from the battery to the other? how do i calculate this??

Asked by ismael01 6 years ago


can usb support two devises ?

Can we connect two phones by one female usb ??

Asked by ah_sala 1 year ago


How come when I connect my psp go to a usb charger, it thinks the charger is a computer, and tries to enter "USB mode"? Answered

 i bought myself a charger for in the car for my psp go system, so i could use the cable it comes with to charge it. but instead, it enters usb mode, and tries to connect to my charger as a mass storage device. 

Asked by k_man93 8 years ago


Will i damage small solar panels on a car battery? Answered

I've got a couple tiny solar panels and i wanted to have them charge a car battery, The panels in series put out 18v at 50ma but the leads are just those tabs they spot weld to batteries. Is it possible to fry the solar panel or leads?  I am not sure about amperage of the battery. It's similar to one i bought a long time ago with 650 Cold cranking amps(not sure how that translates to total amperage but i'm guessing that is how much you can safely draw from it at one time)  i understand that it wouldn't be proper to attach 18 volts to a 12 volt car battery, it charges at around 15 volts like most car batteries.  I understand that 50ma will take an extremely long time to charge something like a car battery. But in a hypothetical emergency situation, would this work temporarily without destroying the solar panels.

Asked by Tomahawk92 2 years ago


How do I build my own Camera Battery Charger using USB?

I'd like to build a Charger for my 8.4v Sony Camera Batteries. I have a few of them but decided it might be interesting to learn how to make one that will utilize USB. From what I understand the Battery is a 8.4v Lithium Ion (i.e.. 2cell 4.2v Battery Pack). The chargers I have state an output of 8.4v and 400mA. I figured it might be possible to utilize the 5v that USB provides and I guess step up the voltage. I found plenty of charging controllers that seem to be good for 1cell (4.2v) batteries, but not seen any way to charge a 2cell battery pack.  I guess I am hoping for some guidance on what I will need to: 1) Step up USB 5v to 8.4v 2) Control a Charge to a Lithium Ion 2 Cell Battery Pack cheers, Jon

Asked by JonathanR10 3 years ago


Problems with USB Port on Homemade speaker box, why can't I listen to music and charge at the same time?

Okay, so I have a speaker box that I made myself with a kitted 7w audio amp. I put that in a box with a decent 4 inch speaker, and that was working great. Then I decided that I really need to add some sound reactive lights, so I got a TIP31 transistor and hooked that up along with a 7805 5v regulator to a USB port so I can charge my devices with it. So, the USB port works great, and so does the speakers and lights. But *not* when I plug in my device to charge while it playing music through the 3.5mm audio jack. It gives off this weird fuzzy sound, but still charges. On my multi meter it shows continuity between the USB port and the audio input and speaker, so I first thought that maybe I didn't have something grounded quite right, but it all appears to be set up right. Is there some sort of filter I can set up so that I can charge one device and play music at the same time on the same device? Or would need to set up the two circuits on different power sources? I would really rather not do that for the simple fact of trying to keep it simple... Here's my schematic of it (sorry about it being sloppy, I did it rather quickly but everything on there should be right). Here's a better quality picture of the schematic

Asked by froggyman 7 years ago