Because we are using a wall-wart (the origional supply for this charger) 100uF input filtering is more than ample. Hence in the pre-boxing picture from the last post, it's a bit hard to see where things are. In the background is the breadboard ith some of the parts still left behind. As is usual for me I order duplicate parts, sometimes in case I blow things up. The other case for spare parts is when you actually want to have a prototype that works, and a finished article at the same time for debugging.
Part 2 adds a 'full' indicator, at the moment the indicator is not bistable, and it does not switch off the charger. Ideally we actually want the trickle-charge step to trip in and out, a little hysteresis should do the trick. Here is the final diagram.
(right-click and view image separately to zoom in)
Since I have not got the enclosure I ordered, (which will go under this bit) that's another reason this project is not yet closed off.