Battery charger
Battery charger
(OP)
Hi
At work I am curntly building a battery charger.
I took a 220v to 10v transformer and took out the secondary windings because I wanted to make it a 12v, I rewinded it with 2.5mm flexible cable untill I got my 12v. The transformer works well untill I connect it to the battery, the current rises to anything between 10A and 17A and the voltage rises to 16v, witch according to me is much to high for charging a battery. When I connect a normal load like a motor or light it works 100%. I have even took out some of the windings to drop the voltage to 11v but still gets the same problem.
What may be the cause of the problem?
Any help would be appreciated
At work I am curntly building a battery charger.
I took a 220v to 10v transformer and took out the secondary windings because I wanted to make it a 12v, I rewinded it with 2.5mm flexible cable untill I got my 12v. The transformer works well untill I connect it to the battery, the current rises to anything between 10A and 17A and the voltage rises to 16v, witch according to me is much to high for charging a battery. When I connect a normal load like a motor or light it works 100%. I have even took out some of the windings to drop the voltage to 11v but still gets the same problem.
What may be the cause of the problem?
Any help would be appreciated





RE: Battery charger
RE: Battery charger
RE: Battery charger
RE: Battery charger
RE: Battery charger
RE: Battery charger
The only explanation I can think of is that your 12V battery is suspect (faulty cell?) and is actually sitting at 10V unloaded. When you connect your tranny + rectifier, the 2V differential appears across the battery's internal resistance (0.1 Ohm say) and so current rushes in to it and the filter capacitor. The inrush causes the voltage of the battery to rise steeply. Perhaps you're unlucky and the inductance in the secondary plus the inductance in the cables happens to form a resonant LC circuit with the capacitance of filter cap and the battery and you get an unstable ringing effect.
RE: Battery charger
i solved the problem...
I just took out the secondary turns that was 2.5mm cable and replaced it with a 1.5mm cable. works like a dream!