Often our bikes Electric starter is not able to start the bike engine or the lights and horn appears weak in their function. The reason is weak battery. To charge it I will show you how to make really simple easy to make and reliable battery charger. I have kept it really simple and even a kid can make it. Not only bike’s battery, you can charge any 12V battery ranging from 5 to 10 Ampere.
To start with you need to make a list of things you need to make it. Here’s the list:
1. Transformer : 12-0-12 Step down 1 Ampere | Quantity : 1
2. Diode : IN4005 | Quantity : 2
3. Capacitor : 1000MFD 25V | Quantity : 1
4. Wires (Red & Black) : Multicore (of width about that of a ball pen refill)
5. Crocodile Clips | Quantity : 2 (red and black in colour)
6. Power chord : AC 220V 5 Ampere | Quantity : 1
7. A box to fit | Quantity : 1

You can get the above parts easily from any electronic items repair shop. Make sure the transformer you buy is of good quality and of 12-0-12 type and not 0-12 How to find that? A 0-12 will have 2 points at out put and 12-0-12 will have 3 points at output (look image). Once you got all, let’s begin assembling the battery charger. I assume that if you have previously made any electronic projects, you must be having a soldering iron, wire, flux etc. if these words sound strange then you can take help of any friendly TV repair technician for the soldering job or if you want to indulge in it then you can get yourself your own soldering iron and learn how to use it. It doesn’t cost much.
To make it easy for you I have done some home work on Photoshop and made a layman’s diagram showing exactly how you have to put together all the parts. So nothing to write much now, just look at the image below carefully and connect exactly how it’s shown there. The blue dots indicate soldering points.

While making take some precautions. To avoid any electrical shock do not plug the circuit when its open. Also negative and positive terminal of both charger and battery should not be allowed to come in contact with each other.
After you complete the circuit, you must fix all the circuit inside any plastic box. Having done that its time to test the newly built charger. Take any 12 v bike battery and fit the red crocodile clip to the (+) positive terminal of the battery and black to the (-) Negative terminal of the battery. Now plug the AC power chord to any AC outlet and charger should start charging the battery now ! A normal 5Ah battery can be charged in 3 hours.
Note: Do not try to charge battery of capacity lower than 3Ah or the battery will explode, or charge battery of more than 10 Ah, else charger will burn.
I built myself a charger using same circuit and it cost me around Rs.130 so cheap !! thanks to mamu bhanja market of Aligarh. later i added some more goodies to it like fuse, voltage indicator etc which ofcource are just fancy things.

This entry was posted on Monday, April 16th, 2007 at 3:20 pm and is filed under Electronics. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.