Parrallel Load to a Charging Battery???

This is not an instructable but a question. See the images for circuit here the 9v battery represents a 12 DC V from an Adapter and the Capacitor represents the Chargeable Battery. Diodes are placed before Chargeable Battery and LED in the direction of current to prevent current in opposite direction. Suppose I have a Chargable Battery of 9v, A 12 Volt adapter (12 volt to charge 9v battery), and a segment LED Strip (3 LEDs in Series.) Now I connect discharged 9V Battery to LED, and adding the 12V DC Input in Parallel as well. I want 12V DC source to charge Battery and Light up LED. I will add protection Diodes as well in positive terminal of led and battery so the current wont flow from the battery. Will the LED light up at 12V at its full intensity? I found somewhere that while a battery is charging, adding something in parallel will draw less current at first and then the Amperage will increase with increase in battery level and then after a lot of time, it will draw as much as current as it would in 12V directly? Is it so, how can I avoid it, i.e, I need the Load (here LED) to get 12 V while that same 12V source should charge the Battery. Sorry for any grammatical mistakes because I am in a hurry. Please answer me. Thanks.

Topic by The Engineer Pro - Mohammed Ayaz Quadri 2 years ago  |  last reply 2 years ago


Connecting batteries in series without wasting the mAh? Answered

Okay, if you connect two 1.5v 1000mAh AA batteries in parallel, you'll get 1.5v 2000mAh, right? And if you connect two 1.5v 1000mAh AA batteries in parallel, you'll get 3v 1000mAh, still correct? What if you connect seven 1.5v 1000mAh AA batteries in parrallel and one 1.5v 1000mAh AA battery in series, you SHOULD get 3v 7000mAh, will that work?

Question by j0rd4nkzf 8 years ago  |  last reply 8 years ago


Question regarding series and parallel circuits? Answered

Hi Guys,              I'm a bit confused in parallel and series circuits and was hoping that someone in the instructables community could help me out. If I wire 3 Blue LED's (3v 20mah each) in parallel their amperage will add up but the voltage will remain same, which means I would be able to run those 3 LED's off 2 AA batteries and it would last for umm.. 2200/60 = 36 Hours. And if I wire those LED's in series the voltage would add up and I would be able to run them off a 9 volt battery for um.. 300/20 = 15 Hours. I wanted to know that if my calculations were right and that in both the ways will they be equally bright. Thanks in advance :). UPDATE I was a bit confused how to wire it up in parallel so I made a diagram can you guys tell me if it is correct?

Question by The Prickly Potato 4 years ago  |  last reply 4 years ago


charging and discharging lipo and lead acid batteries in series/parrallel

Is it possible to charge a lead acid battery and a lipo battery of the same voltage but a different amperage in parallel , and discharge them in series , without one of them blowing up or being damaged? i want to charge a battery pack in series with a 12v charger , and run a 24v dc motor with them...

Question by wiebevandomburg.hotmail.com 8 years ago  |  last reply 8 years ago


just wondering how to use some of these cnc stepper controllers with usb ?

I dont have parrallel ports on my computer only usb. i would like to run a machine from my compaq presario laptop.

Question by poc 9 years ago  |  last reply 9 years ago


Need help

I need some help trying to make a circuit for an instructable im gonna post. its supposed to be a candy jar, with leds in the cap, but i cant figure out a ciruit for all the Leds to be on a series circuit. can some one tell me if this is possible, or do the leds have to be on a parrallel circuit. im new to electronics.

Topic by lawizeg 11 years ago  |  last reply 11 years ago


solar install question

Ok so I see a few solar setups online. now I have been researching for a while on this and no one can give me the answers so here i go on here. So i want an UPGRADE-ABLE solar setup. right now I have 2 150ah 12v batteries. I have multiple 50 amp charge controllers. so when I buy the solar panels I can plug in and get batteries going no problem.... My issue is the mains voltage side of things. I want to have something like a fuse box, this will have my main breaker and then the independent safety switches. the issue is to do this I need to make sure all my power is on 1 line. so if I buy a few small inverters I will not be able to piggyback them as they tend to go bang. so what type of inverter can I get that will be able to go in parrallel to allow me to get more amps if needed? I am hoping there is one that is infinitely upgradeable just in case. TLDR what type of off-grid inverter allows parrallel connection to other inverters??

Topic by plucas1 1 year ago  |  last reply 1 year ago


where to get FREE CNC software (for XP)?

Hey, I'm building a 3-axis CNC milling machine. right now I'm looking for a FREE ( or VERY CHEAP) CNC software... I would like something "common" since that'll be the easiest for getting help later on... I'm thinking of MACH3 (since that's what I've seen that diy'ers use mostly) ... anyone knows where to get it? (I'm using XP, because I've got a computer for free, since my usual computer is a laptop and doesn't have a parrallel port, and i wish to use a computer ONLY for CNC)

Question by lordl9999 6 years ago  |  last reply 6 years ago


Trying to make custom LED tail lights for my Honda S2000.

Hi all,     Anyone have any good DIY for wiring up LEDs to a 12V system? I found LEDs on ebay with resistors already wired in but im wondering if I should hook them up in series or in parrallel? Im sure 12V is enough to power them but how can I make sure they dont burn up? Is there a way wire up the LEDs to keep them looking straight and in line w/o taking for ever and postioning them perfectly? Maybe some kind of board or plate? Thanks

Question by rugsr 8 years ago  |  last reply 8 years ago


can I wire 3 small 12 - 36v dc pm bl motor wind turbines output into 1

Ok...I have 3 mini wind turbines ..2 are 12 v dc and 1 is 36v dc they definately put outa shock when spun by hand! so what I want to do is combine the power outputs of these 3 motors into in one 48v  +supply A.do I wire them in series with diodes between..or in parrallel?..I hear both ways, but that cant be or do I wire them all (with diodes) to a "single" connection  (1 for + and 1 for -) B. what size/ type of diodes should i use on each motor (preventing back powering the motors) ulitimately I want to invert this power into 110 ac  but with decent watts any insight or help is greatly appreciated!!

Question by schel 8 years ago  |  last reply 8 years ago


Troubshooting my Solar cell phone charger, why doesnt it work?

I recently wired up a solar charger and I have having issues with it not charging my device.  My setup consists of two(2) 5V 100mA solar panels wired parrallel to bump my amperage up to 200mA conected to a 5V step-up USB charching circuit.  I have been able to read 5V coming out of the panels and between 200-300mA but when I plug my phone into the USB cable, i get nothing.  Am I missing something?  Is there a minimum amperage I need in order to charge my phone?  It is an android, motorolla btw.  Here is the power converter that i am using. http://www.amazon.com/DROK-Power-Converter-Module-Charge/dp/B00C93Z8JY.  Please help!

Question by jdb257 4 years ago  |  last reply 4 years ago


Galaxy D III Samsung cell phone battery pack

I have a Samsung Galaxy S III cell phone with the original battery. It does not last near as long as i want it to. I can buy a better battery pack... but why? I found this ad for batteries.  Why not hook them in parrallel and have a decent, log lasting backup? I just need some instructions before I trash a perfectly good smart phone.... Product Description: Brand new and high quality.  Standard voltage is 3.7V, the voltage of full charge & empty condition is 4.2v & 2.5v respectively Particularly suitable for flashlight, electric tools, electric bicycles, electric vehicles Capacity: 5000mAh Voltage: 3.7V Material: Li-ion Dimension: 65 mm (H)x 26 mm (Dia) Package Includes: 2 X 26650 3.7V 5000mah Battery I already have a charger for these batteries.

Topic by GrumpyOldGoat 5 years ago  |  last reply 5 years ago


How do I wire my 2 led strips in parallel?

Hi, I have 2 LED strips (5050) which I want wired in parrallel. I only have 1 power supply driver which is only enough to power 1 LED strip. That's okay since I don't want the 2 strips to be on simultaneously. My question is this: I need each LED strip to be controlled by the same switch. So for example, if I switch on once, the top strip lights up, if I switch on twice, the bottom strip lights up. What parts do I need for that to work? Alternatively, if that's too hard, I could use 2 switches instead. But could I still use one power supply driver? (i.e. is it okay if I plug the 2 LED strips +wires to one hole and 2 -wires the other hole in the power supply unit? I have attached a diagram...

Question by eyang5 6 years ago  |  last reply 6 years ago


LED Strips

Hey everyone! Ive been on this site for awhile, and find it simply amazing. And now I have a simple question for some electricians :) Im OBSESSED with light, literally OBSESSED. the only bad thing, is I know NOTHING in electronics, but ive started learning and am trying to assemble a very simple led strip light with some conductive tape, and 12v power supply and about 16 leds. (yes i know there is a bar tutorial, but i need some explaning on a few parts.) I want to just have 16 leds in a parallel or series, (prefer parallel) so it can be put on a very slim piece of wood/metal/sheet or wherever i place it. I tried using the ledcalculator, but it keeps telling me i would need a resistor for EACH led, and that would just defeat my set up being "small and simple" So is there anyway to just have ONE resistor in the VERY beginning, to limit the current of 12v down to 3.5 to supply to all the 16 leds? Kinda like in my drawing (that is bad) Because i want the assembly to be as small as possible, and would like not to use one for every LED And also, how many leds would i be able to drive in a parrallel with a 12v power supply? Thnx so much in advance!

Topic by mu0p 12 years ago  |  last reply 8 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???

Question by supramp 7 years ago  |  last reply 7 years ago


What is the safest (and most reliable) way to power a dozen LED's burried in a floor?

I know sculpting and carving, not circiuts! I've added some custom glass etchings to the tile floor in a bathroom that are lit with LED's embedded under the Travertine and Grout. There are about a dozen 3v White LED's spread throughout the floor and all wired in parrallel. They are hard to change. Once they burn out, they most likely won't be dug up and chaged, so I want them to last as long as possible. In my previous installation, I simply used a 3v battery pack inside the closet with a wall switch in the entry to control the circuit. In my current floor, I've also used a battery pack to test them and am now ready to build a permanent solution. This time (thinking ahead) I have built a switched outlet in a wall cavity that will provide power to my floor lighting. The question is this: What is the best way to power them making use of the switched outlet? My original idea was to simply buy a 3v wall wart power supply typically rated at between 750 and 1000ma at the switched outlet. The reason I'm asking you fine folks about this is that Im concerned about providing too much amperage to the lights and burning them out (if that's possible). Once they're gone, theyre gone. It is not very practical to dig them out. Is this a good idea? There is nothing else in the circuit but the 3v LEDs and the power supply (no resistors, etc). My backup idea is to use a 120v relay and a battery pack at the switched outlet. This seems the safer solution (less chance of burning out the LED's), but would require changing the batteries once in a while (probably every couple years with typical usage.

Topic by briankangaroo 9 years ago  |  last reply 9 years ago


How to setup an LED hunting light?

I'm trying to copy something I've seen online...without buying it. So I dont have a light to look at in order to copy it. I'm doing this for my own use, not to sell, so i'm not trying to take business from anyone. Online they have hunting lights that are green LED's that hang below a feeder. These are used for wild hog hunting since they usually come out to feed at night. They cannot see the green light, but green is easier to see at night to the human eye. I'm wanting to power it off of the 12v battery in the feeder since I have it charging with a solar panel. The LED's i found online for fairly cheap are super-bright 5mm green LED's. It says they give off more than 8000 mcd (light rating?). They require 3.2v (3.4v max) at 20 mA. I've looked at some of the posts on this and wanted to know if my math is right on how i can set these up. I figure i would wire 3 in a series, which would require 9.6v. Using Ohms law with a current of .020 Amps, I get (12-9.6)/.020=120 Ohms So, 3 LED's in series with 120Ohms worth of resistors and my 12v battery will power it fine. The part i'm not sure about is how the current works with this. The battery is 12v 7Ah. Will that fry them or is the current the amount of juice it has? If i wanted to make a light with say, 30 LED's, can I make these 3 LED units and wire multiple units together in parallel? so each unit would power off of the 12 volt and the parrallel units? Hopefully this makes sense. Will this work? Is this the best way? Any suggestions or comments would be appreciated. Thanks.

Question by AggieTX 7 years ago  |  last reply 7 years ago


electric shocker resistance and housing problem, i only have a week or two until the secret santa party

In an attempt to provide a rather "interesting" christmas present as a joke for a colleague i have assembled an remote controlled electronic shocker device ( perfectly safe almost no current at all) by wiring an electric shocker of a design i am familiar with making so that it's power is provided by wires which previously went to the motor of an RC car( i intend to do an instructable on how it was built, if i get it to work!). the arrangement is constructed from the charging circuit of a disposable camera with the capacitor chopped off and replaced by the electrodes that will connect to my receiver's( my colleague) hand,  the AA battery has been replaced with a remote controlled power supply ( same voltage and ampage as an AA battery)system. Enough on what i have built( unless you need more details to help me), here is my problem. I had originally intended to place the shocker in a small box and attach each output high voltage wire to a tin foil half wrapped over half of the box( i would cover the join with a ribbon) the plan was that when someone picked up the box their hand would form a connection across the tin foil halves and therefore their hand would be acting as a resistor in a high voltage circuit so a (very tiny less than 0.25 milliamps) current would pass through it( whether the voltage is applied across the two halves can be controlled by a remote hidden in my pocket so when other people pick up the parcel they get no shock). but i have found that ,although the output wires are at a high enough voltage to shock someone, the resistance of the tin foil means that the remaining voltage to go across the person's hand is not enough to shock them. ALSO the shocker will work across about a centimetre of skin ( like touching both wires with the tip of the same finger) but when the contact points are as far apart as a whole hand( like thumb to last finger) the increased resistance of the hand means that the current is so small that i cannot even feel a tingling when i test it( i had a few (willing volunteer)friends who are working on this with me also test but it could not shock them either). so my problem is that i must either find a much lower resistance form of contacts to coat the halves of the box( i have no means of using expensive materials or ones that need to be heavily worked on before attaching( like metal plates that must be attached to each face of the box)) or a ( very quick and simple, i only have about a half an hour slot of time to do any soldering before the party ) way to boost the voltage ( i was thinking of attaching extra batteries but suspect this would not work and also am unlikely to get an opportunity to do much electronic alteration) or ( most promisingly) must find a way to house some very bulky parts in a housing where i can guarantee that my colleague will touch both electrodes with one finger without suspecting anything until he gets shocked( this needs to be something like the switch on a torch rewired so that the electrodes are on the switch or whatever, or any other gift where the "obvious" thing to do is put a finger on a certain metal point for some reason( preferably when picking the present up)).  I have already addressed any safety concerns so please do not criticise me for this as electric shocks are harmless provided the current is low enough and does not cross the heart.( i have a very low current with both electrodes on the same hand on top of which it only shocks when i press a button on the remote). ALSO please do not suggest i rebuild the whole circuit as i know that the circuit works fine and i do not have time to build it all again or do any serious modifications, THANKS  any answers would be appreciated, THANKS i think i have found  solution,it is really awesome and involves placing a battery in parrallel with the power lead into the shocker from the remote control system. i am not sure why it is working but i suspect some effects similar to capacitors are involved, the really weird thing is it does not shock you when you grab the box but rather when you pull your hand away. incase i find any other problems this thread is still open to suggestions and ideas for other solutions, assuming the system works perfectly after i have soldered my modifications in place( a few days time before i get a chance to use a soldering iron) then i will no longer need any help( providing nothing else goes wrong). thanks for reading all of this.

Question by resistanceisfutileiflessthan1ohm 6 years ago  |  last reply 6 years ago