# Converting a forklift charger for EV use



## puddleglum (Oct 22, 2008)

I would really appreciate some feedback on this, even if it is to say that I haven't given enough info to answer properly or it is a stupid idea that couldn't possibly work.


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## major (Apr 4, 2008)

puddleglum said:


> I would really appreciate some feedback on this, even if it is to say that I haven't given enough info to answer properly or it is a stupid idea that couldn't possibly work.


O.K. You asked for it  You can run a 3 phase charger like that on single phase with reduced output, but it would need to be at the same input voltage. These are typically ferroresonant type (?) and not adjustable (much) for output. In short, there isn't a easy way to mod it for your use, IMO. 

But if you do figure it out  let me know. I have 3 of those (12, 24 and 48V).


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## puddleglum (Oct 22, 2008)

Thanks major, that is all I was really needing to know at this point. I think the motors are still worth the price if the forklift. I just thought this might be a bonus if it could be made to work.


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## Coulomb (Apr 22, 2009)

puddleglum said:


> I think the motors are still worth the price if the forklift. I just thought this might be a bonus if it could be made to work.


If you happen to have an induction motor of reasonable power, there is a hack for converting single phase 120 V to three-phase 208 V. That might be worth a bit of a fiddle if you are interested. You may not get full power, depending on the motor and other things. As usual, Google for details.


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## PStechPaul (May 1, 2012)

48V 115A is 5.5kVA, so you can't get that from a normal 120VAC outlet and even on 240V you would need at least 25-30A especially if you do not have PFC (which is really not as much needed for three phase). The only way to get three phase power without need for very much PFC would be a large single phase 230 VAC motor (about 8HP) and a similarly sized three phase motor which may also require some modification, or a three phase synchronous generator. And if you go to all that trouble you might be able to use a direct DC generator and not worry about rectification and filtering.

There are probably very few components of the 48V charger that could be used for a 144V charger. The rectifiers are probably rated for no more than 100V or even 200V which is too low for 144V, and the three-phase transformer probably cannot be rewired for 144VDC output. If they are three separate transformers, however, they might be able to be reconnected with primaries in parallel and outputs in series for 144V. But with single phase you will need a new rectifier and also capacitors and maybe inductors to smooth the output. It will also need a control circuit to charge at the correct voltage/current/time parameters.

Actually the charger may be even more useful as a welder or plating supply, or you might be able to sell it for its intended purpose. If you can trace out a schematic of the power components and any nameplate data, it will be easier to determine what can be done.


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