Using a 12V Battery Charger in Reverse as a DC to AC Converter

Nope. It is a completely different circuit topology converting DC to AC (inverter) than to go from AC to DC(battery charger, power supply).

In a power supply the non-linear nature of a diode is used to dramatically change the frequency spectrum of a nearly pure single frequency signal into a collection of frequencies that have a dominant DC component. A low pass filter network (capacitor) then reduces significantly the non-DC components. Running a DC signal through a diode does not generate an AC signal.

Now I'm not saying that a clever engineer couldn't use the parts of your forklift power supply to make a low voltage high current oscillator that then stepped up though the existing transformer to 120VAC. But just reversing your diodes is not going to do it.

Just buy an inverter. They're as cheap as chips.

True, this way the batteries in the forklift can still get charged.

_{Such an enormous machine just to lift a fork.}

People had been working for ceturies to:

Not possible. It is just AC to DC converter. You need DC to AC inverter do achieve this. The modern small power home inverter using a new technology called "Bi-directional line interactive SBS" using this technology of using same transformer for conversion and inversion. Much information available on web.

I suspect that you understand that it doesn't quite work that way now!

Tell us exactly WHY you want to do and CR4 will help out with How?.....

Because it was there (left over when I had to close a business) and because I had some thoughts on building a small wind generator.

Everyone has pretty much confirmed what I felt was the case all along but I figured if there was a way someone on CR4 would know it and pass it along.

Don't know till you ask!!! Time to put it on eBay.

Thanks for the responses.

but you can use an UPS to convert DC to AC, most UPS's go out becouse of battery failure anyway and that's what you take out and wire the DC to. Oh yes, disconect the buzzer

1.from 12volt DC you have to convert to 12 V AC by half bridge inverter with 2 power transistor or full bridge inverter 4 power transistor and additional flywheel diode will be advantage for switching.see simple typical connection on power electronic book or web

2.you have to make simple circuit to trigger the base of each transistor/switching. and adjust the frequensi to 50hz by R-C (with potentio to adjust resistance to get correct time:20 ms)

3.after that you need a filter capacitor to make a good sine wave.12 volt Ac

4. increase the voltage 12 volt ac to 220 vac by step up transformer

i was done same way and succesful in the laboratory during power electronic class

Use inverter insted of battery charger. This will solve your problem.