This is the circuit of a simple 12 volt battery charger for Lead Acid battery. It gives 12 volt and 5 Amps current for quick charging of the battery. If the battery is partially discharged, full charge will be attained in one hour.
The circuit uses a 0-14 volt 5 Ampere Step down transformer and a 10 Amps Bridge rectifier module to convert AC to DC. Since pulsed DC is good for Lead Acid battery, a low value smoothing capacitor is used as C1.To monitor the charging status, Ampere meter is provided in the positive rail. LED act as the Charger on status.
Simple 12 Volt Battery Charger Circuit
When the output is connected to the battery terminals, the meter shows a higher reading depending on the current flow into the battery. As the battery attains full charge, its terminal voltage rises to 13.8 volts and current through the meter ceases. The meter reading then returns to zero. This indicates the full charge state and the charging can be terminated.
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George
has anyone tested this?
does it work?
I’m using the same trick but instead of using 14V trafo, I used only 10VAC. So if it is converted to DC (10 x 1.41) it will approximtely convert to 14VDC which is still in controllable range. Ammeter could be replace with voltmeter too but must be parallel connection.
hi, can anyone explain why ammeter is needed and is it possible for the circuit to work without the ammeter… thanks in advance…
It will work fine without ammeter, but the ammeter provides a good means of telling when the battery is charged because the current drop off greatly.
You can make your own ammeter by placing magnetic compass next to the wire and observing deflection.
Or you can buy an inexpensive DC “clamp-on” ammeter at your auto parts store –I have on that I use all the time. The insulated lead simply is place into the slot.
This circuit works but why the 100 microfarad cap? Make you secondary 10 volts and it will not “cook” your battery due to overcharging. I did this with unattended industrial units and this was the most reliable.The batteries were on a battery operated fork truck and the transformer used was a 500 watt unit charging 180 ampere hour batteries for over 10 years. The batteries lasted a lot longer than on a electronic controlled charger 3 years instead of SIX months!!(With stacks of I.C’s and some with Microprocessors)
hi, i tried this circuit with a 15v, 1A center-tap transformer, the transf was superhot. i guess d power rating is low so, can i use a power trnsistor to boost d current from d transfmer output? Thanks in advance.