What are the best Discmans

Hello Jorge!

I am very curious about your solution. I thought about doing the same but, as someone who is more comfortable around oil than electronics, I doubted if such an approach would work. I have a couple of questions, if I may:

1. Why does adding a second row of batteries would increase the charging current? I thought that the charging current is defined by the charger. Hence, adding 10 additional batteries "in parallel" should result in double the charging time, instead of double the charging current. My apologies upfront if my reasoning is sheer stupidity. Again, oil nice, electronics not so.
2. How do you balance the batteries, or do you een balance them. AFAIK NiMh batteries are less picky in terms of balancing (at least relative to lithium cells). After a long chat with Copilot, a passive balancing circuit was recommended. A simple resistor between the two battery banks should do the trick (namely, a resistor in parallel to the connection where the center tap for ground is). My gut tells me that such a solution is not reasonable.
3. Depending on the batteries you used, the voltage of each cell can potentially go above 1.2V, which would imply that the charger should provide more than 12V to charge the pack. Assuming AAA Eneloops, the voltage goes from 1.2V to 1.6V, meaning the charger needs to provide up to 16V to charge the pack completely. Is the logic correct? If so, how did you dealt with it?

Thank you very much in advance. Any hints and/or advice is appreciated!

 

I have restored 2 x Discman batteries but they looked like new old stock with distilled water and they now charge up fine.
A few others that looked used did not recover.
The usb-C charging battery from Aliexpress works perfect in my D-150 and D-88

 

The battery on my SL-XP5 was damaged beyond repair. The cells were dry and the contacts very corroded. Hence, I doubt there was even a chance to restore them. The USB-C batteries from Ali are unfortunately incompatible. But would appreciate a link to the specific one you are using. I could use some rechargeable batteries for my other players.

 

my advise - if not comfortable about some advise re. batteries or power supplies - do not follow them! I burned one of my D-90 because of a bad solder joint on my self-made Li-Ion BP2 battery. It is truly amazing how much contradicting but professionally articulated info can be Googled on LiIon, LiPo, NiMh and NiCd batteries.

@Eryan - Q about the second bank of cells: charging circuit in Discmans is very basic, it just supplies correct charging voltage and internal battery resistance determines charging current. Second set of batteries in parallel drops the resistance by the factor of 2, current may rise to over 1amp which Discman cannot handle. I suspect that most burned D-15 and D-25 failed while charging aging BP2 batteries
For SL-XP5 Ni-Mh batteries were simply soldered in series of five, to provide +6V and -6V for the player. Charging voltage from the adaptor is +7V and -7V.
3.7V Li-Ion and LiPo cells is a perfect fit for reviving Sony batteries. @rcpilot23 - how much play-time are you getting from re-soaked PB2?


Since this thread is still about The Best Discmans, here is the latest addition to my collection. I did not even know that SL-NP10 in Red existed until I bought one!

 

First things first: that is a gorgeous unit you have there. That is the same as a SL XP5 right?

Regarding the batteries: I understand now. I'll go with a single bank of batteries then. Since you did not mention the balancing, I'll assume it is not relevant. Out of curiosity, how long does it take for the 10 batteries to charge? And does the battery meter on the player works when using the 10 AAA?