an additional comment: On my old 45 CT 1 I have measured a voltage of over 230 V between the two contacts of the plug if it is charged! This high ignition voltage maybe can damage modern electronic cameras. There was a certain serial-number after which the voltage was lower and safe.
No capacitor in the AA holder of my 45CL3 or 45CT4. The original owner manual provides no explicit warning against the use of rechargeables in the 45-39 AA holder, although the instructions do say "use only alkaline manganese batteries of size IEC LR 6 (penlight cells size AA)"
The 45-40 Nicad pack from Metz is not one that is designed for the user to remove and replace cells. The Nicads in this holder are factory installed in the pack.