Ryobi battery charger transformer

[WbSearch]

I have tried without luck to find the break in the wiring, or to locate a
replacement transformer. No one in the local shops, or Google search can
crossreference the transformer number ES-66-287-1245.
Can anyone help with any transformer manufacturers I could try?
The battery pack has 10 NiCads, so I am assuming the charging voltage would be
14.5 v, 1.45 volt/cell according to the GE NiCad book. Can anyone advise if I
could use a 15 volt transformer? I cannot find any reference to voltage within
the circuitry.
Thanks.

 

[Eric Vey]

Yours burned out, too? So did mine and my father's. My father called the
service center and they said "Oh! You are supposed to unplug it when you
aren't using it."

Most of the Nicads I have seen are rated at 1.2 volts although after a
charge they put out 1.4-1.5, but that doesn't last long. Once they get
down to 1.0, that's it.

I have done a bunch of reading about charging Nicads. Not very
sophisticated. Voltage not super sensitive (unless you want to guarantee
absolute maximum life), just a transformer, and maybe a circuit for
detecting a full charge. A way around that circuit is just to time the
charge.

 

[WbSearch]

The GE design guide designates charging voltage at 1.45 v/cell, use rating is
1.2v/cell. I had an old transformer from an IkeLite underwater light that has
22 volt output. Physically is same size. Put it in and it works fine.

 

[Eric Vey]

--designates charging voltage at 1.45 v/cell--

Got it.

--22 volt output.--

That's a little "hotter" than I would dare use, but I won't argue with
success. You gonna start unplugging it now?

 

[WbSearch]

Eric,
The 22 volt was too hot, charger cycled alot and batt's didn't get over 13.9
volts. The transformer I had was a center tap so I tried the 12 volt center,
too low. So I went back to the 25 volt (actually), made a voltage divider from
2 resistors to get 15 volts and it worked fine. So I'm now going to look at
the local parts supplier for a 15 volt transformer, don't like the idea of
packing large resistors in the case. I willtake your advise to unplug it. I
got this from my nephew that someone he works with was taking to the tip.