cordless drill charger

[lurk]

trying to trouble shoot a black/decker charging unit.....it over heats
quick and hot......I replaced all components but still over heats....help ..
thanks

 

[Smitty Two]

trying to trouble shoot a black/decker charging unit.....it over heats
quick and hot......I replaced all components but still over heats....help ..
thanks

could be the battery you're trying to charge is shorted. did you try
more than one battery?

 

[lurk]

I was thinking about the battery being shorted...but not tried another
battery yet....this is about the 3 rd charger I seen with this
problem....they get so hot it melts the plastic....maybe they are only
made to last so long......thanks for your response

 

[[email protected]]

I was thinking about the battery being shorted...but not tried another
battery yet....this is about the 3 rd charger I seen with this
problem....they get so hot it melts the plastic....maybe they are only
made to last so long......thanks for your response

After a few law suites over cordless drill charging units causing
fires some manufacturers have intentionally made the chargers
lightweight
so that they will fail before any possibility of creating a fire.


Replacement chargers that will not burn out, or get hot so easily
are available on e-bay.

 

[ian field]

trying to trouble shoot a black/decker charging unit.....it over heats
quick and hot......I replaced all components but still over heats....help
.. thanks

The B&D cordless I have can't get hot as it has a thermal fuse bound into
the transformer primary - or at least it did until the pack developed a
couple of shorted cells (normal for B&D!) although they do run warmer than
you might expect in normal operation.

You can easily tell if it has shorted cells as the transformer primary goes
O/C and stays stone cold when plugged in.

 

[hr(bob) [email protected]]

The B&D cordless I have can't get hot as it has a thermal fuse bound into
the transformer primary - or at least it did until the pack developed a
couple of shorted cells (normal for B&D!) although they do run warmer than
you might expect in normal operation.

You can easily tell if it has shorted cells as the transformer primary goes
O/C and stays stone cold when plugged in.

Does the charger overheat when plugged into the AC power but no
battery plugged into the charger?

H. R. (Bob) Hofmann

 

[lurk]

It does not over heat without the battery plugged in....which makes it look
like no load no overheat

 

[hr(bob) [email protected]]

It does not over heat without the battery plugged in....which makes it look
like no load no overheat








- Show quoted text -

What is the nominal voltage of the battery pack? Have you measured
the open citrcuit voltage of the battery pack, ie just sitting on the
bench?

H. R. Hofmann

 

[John k]

Does anyone know what the value is of the Thermal Fuse in the Black an
Decker charger? I'm looking to replace mine. It's for an 18V charge
model PS1518bu

 

[ian field]

Does anyone know what the value is of the Thermal Fuse in the Black and
Decker charger? I'm looking to replace mine. It's for an 18V charger
model PS1518bu.

All the one's I've seen (though not so far an 18V) have the thermal fuse
bound tightly onto the surface of the primary winding and is almost
impossible to cut away without damaging said winding.

Usually the voltage and VA rating is marked on the wall-wart part of the
charger, so raid the junk box for a replacement with the same ratings - I
used a Hayes modem transformer to repair the 12V charger and an ex printer
wall-wart for the 14.4V drill.

Once you've replaced the O/C transformer, open the cradle section of the
charger and check for a limiting resistor along with the 4 diodes, if you
still have shorted cells the resistor will overheat, discolour and possibly
change value - making it difficult to find the correct replacement, as it is
you may have to make a "best guess" if the resistor is already discoloured
and the value drifted.

If you plan to attempt unsticking the shorted cells, temporarily replace the
limiting resistor with a 10W WW and connect the partly dismantled pack to
the charger with fly-leads. Unsticking current is supplied by parallel
connected H4 bulb filaments from a 12V SLA battery - some cells might be a
bit stubborn, if so short the H4 filaments for unlimited current but only
flick the wire on!

Take very great care to only apply the unsticking current with the correct
polarity for each cell in turn or the short will become permanent!

As for buying new batteries, last time I checked B&D were charging so much
for replacements that I could have bought 2 new better spec drills for what
B&D were charging for 1 battery! The 14.4V drill was new - I already knew
better than buy anything else from B&D when I found the 12V drill left out
by the bins (usual fault - S/C cells & O/C transformer). Next time they pack
up, I buy a different brand that isn't expensive crap like B&D!