After I found a replacment for the old PB-S5(A) gumstick batteries I was thinking about a more comfortable solution to charge the two small NiMH batteries. It was annoying to take them always out of the Walkman and put into the universal smart charger. I checked, whether my smart charger can charge both batteries in series so that I could keep them in the Walkman. Unfortunatelly my smart charger was to smart. It is intended for single cells only (AAA, AA, ...) and so it did not recognize both cells in series.

So I searched for another charger, which can charge battery packs, check the status of the cells and finish charging automatically.

I found the following for 34 Euros at Amazon:

It is worldwide usable and has a plug which fits into the external AIWA battery box.

Now I had to build a charging stand. I searched in the garage and found an old aluminium plate, which I bent a little bit.

After that I sprayed some paint on it and put some self-adhesive sealing rubber stripes. Then I screwed on a battery box with bypassed voltage regulation (desoldered all components from the PCB) and - voila, the stand is ready.

So I can put all my Wakmans, which use this battery box, to the stand.

Attached the new charger and it works.

Around 3 hours later:

As an experiment I checked, whats happen, when I put the Walkman without Batteries on the charging station. For that I used one of my RX810, which is not in full working order.

I tell you - NEVER TRY THIS!! After putting the Walkman on he stand, I could hear a sound like a starting jet. The motor was speeding up and the LCD display was flashing. 

I thought the charger would recognize, that there is no battery inserted, but he didn't. So I think, this case would damage the electronics.

The normal charging for a RX810 lasted around 2 hours, for a JX707 around 3 hours. Maybe the 707 was longer, because of additional charging for the memory battery. Or maybe the batteries had diffferent loading status at the beginning.

Finally, the built charging station now works well, even when it will not get a design award.

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