Hi everyone. I recently found my old Sony D-25 Discman which I bought in the late 80s. Was surprised the thing is still working when I plugged in the AC adapter. However, both the BP-2 and the BP-100 batteries I had were dead as a dodo. Looking through ebay, there is repair service for both from the same seller (KaosunCD) who will replace the battery cells with Li-Ion. However, repair for BP-100 would require modification to the CD player itself. I want to keep the Discman in original condition so I started looking at the spec of the BP-100 which was rated at 1000mAh and 6V. So I started thinking if it is possible to replace the old lead-acid battery cells in the BP-100 with 5 of the Ni-MH gumstick batteries in series. I'm referring to replacement gumstick batteries for old Sony Walkman available at sites like Amazon and ebay which is rated at 1.2V and 1450mAh each. So 5 of them in series would be 6V at 1450mAh which would allow the Discman to play longer compared with the original lead-acid battery. The question is whether this setup would work and if the replacement Ni-MH batteries can still be charged with the CD player/AC adapter without modification. Thank you all for your help.
Wish I knew the answer but i like the idea, I sent that specific ebay seller my D-88 with its battery. He fixed the CD player and rejuvenated the battery with lithium ion. It worked fine once i received it. The CD player and the battery was kept sealed in the closet for over a year. Few weeks ago I decided to place a video clip of D-88 on my Instagram. CD player works but the battery is dead again since i didn't recharge it for long time. So I have to send the battery to him to rejuvenate it again/.
