SMPS capacitor test question

[Cydrome Leader]

I noticed the lithium battery for my nikon camera was acting as it it had
a bad cell. It would charge, but just not last very long. The battery is
"smart" with a third terminal that the camera talks to. It shows perfect
"health" which is total nonsense after 2 years of use and the fact that it
doesn't work right.

THe charger itself is is little less smart. It charges the battery at 8.4V
and 0.9A or something like that, but using only the + and - terminals
from the battery pack.

I also noticed it got pretty hot, so I opened it and found very few parts
aside from some 20+ pin charging controller and pretty basic switching
power supply. The transformer and filter caps were pretty hot. The older
Kodak/Sony AA NiMH chargers seriously look more complex than this charger.

I guess it's expected that that cap will warm up at whatever crazy
frequencies they use these days in compact power supplies, however while
it would fail my standard for the touch test, it may still be in spec.

Is a capacitor ESR meter of some sort going to be useful for testing the
cap? What frequencies do they test at?

While I could just replace the cap and not worry about it, not being able
to test it is the issue I'm more interested in solving.

 

[Arfa Daily]

I noticed the lithium battery for my nikon camera was acting as it it had
a bad cell. It would charge, but just not last very long. The battery is
"smart" with a third terminal that the camera talks to. It shows perfect
"health" which is total nonsense after 2 years of use and the fact that it
doesn't work right.

THe charger itself is is little less smart. It charges the battery at 8.4V
and 0.9A or something like that, but using only the + and - terminals
from the battery pack.

I also noticed it got pretty hot, so I opened it and found very few parts
aside from some 20+ pin charging controller and pretty basic switching
power supply. The transformer and filter caps were pretty hot. The older
Kodak/Sony AA NiMH chargers seriously look more complex than this charger.

I guess it's expected that that cap will warm up at whatever crazy
frequencies they use these days in compact power supplies, however while
it would fail my standard for the touch test, it may still be in spec.

Is a capacitor ESR meter of some sort going to be useful for testing the
cap? What frequencies do they test at?

While I could just replace the cap and not worry about it, not being able
to test it is the issue I'm more interested in solving.

An ESR meter such as the Bob Parker Blue now available from Anatek Corp,
would tell you the story. It tests at around 100kHz, as I recall. It's not
an expensive instrument, especially if you build it yourself from a kit, and
is certainly endlessly useful in a commercial workshop. For non-commercial
casual use, still cheap enough to be one of those 'nice to have' items ...

Arfa