Xbox Play & Charge Kits

[Carlmundo]

I have 2 Xbox play & charge kits (battery and charger) and for a while now they don't seem to be charging the battery.

When the charger is plugged in to the controller then it works fine but no red light to say it is charging. Once you unplug it, then it usually says "controller disconnected" a second later.

Any help here is most appreciated as I have to use batteries or deal with a cable connected controller all the time.

[Retodon8]

If your controller disconnects, the battery is be empty.
Since it doesn't disconnect when you use the kit, the kit must still supply power.
This seems to indicate the problem lies with the battery.

If you know somebody with some know-how and a multimeter you could ask him/her to test the battery (or both batteries in your case).

Actually, let's try Xbox.com's search feature.
I found:
While you attempt to charge your Xbox 360 Rechargeable Battery Pack by using the Play & Charge Kit, the light on the cable is not illuminated
and
The Rechargeable Battery Pack will not charge while connected to your Xbox 360 Play & Charge Kit
which seem relevant.