I have been given a Bosch battery charger (along with a battery) for a
fairly chunky looking battery powered drill.

The problem apparently is that the charger does not charge batteries. The
battery appears to have about 15vdc (marked as 24v 1.2Ah). I have popped
the covered off the charger, and there is about 35vdc across the charging
terminals.

However when I attach the battery, the voltage drops to about 15vdc - as if
the charge has no current supply.

I have had a quick look at the circuit board and it looks ok. There is also
an LED attached to the board which briefly flickers when the battery is
attached and then goes out again.

I was lead to believe the LED is meant to flash until the battery is charged
and then remain on to show 'fully charged'.

The details I have for the unit a Typ 1617 224 006 (then 820 in an
ellipse)
prim: 240vac, 50/60Hz, 30w
sek: 24vdc, 0.6a, 15va

Any suggestions?!

Cheers,
Matt

ps. device is apparently a bit over a year old, but has not had much use.