Hello,
I build two MB-6582, working perfectly.
I have used psu option B and build my own psu with 5VDC und 9V AC (Tranformer 2x9V und 7805 with 3A max. )
Under full charge the 5V DC drops down to under 3V. I have tested this with 3 different power supply units (regulated power supplys)
For both MB-6582 I need a no-load voltage of 8V.
I am pretty sure there are no short-cuts etc. I did some current measurement and there are no uncommon currents.
Any suggestions? Maybe because of the 22