I have a few from this series in my collection and always hated the large battery adapter so I was thinking to try to build my own adapter for the gumstick battery when I found this on Aliexpress. It's a rechargeable battery (USB C). So I ordered one having little hope that it should be good or even arrive but to my surprise it was actually well built and worked great with no problem with the contacts to the player. I'm not sure I would recommend it as I'm quite sceptical to this kind of solutions and Chineses builds but I decided to take the risk. Naturally when I went back to order batteries for my other players the seller was not there anymore. I found another seller so I ordered additional batteries from there. Do anyone have experience from this kind of solutions? Many of the Walkmans in this serie is sold without battery compartment or with a broken one.
One note, it is quite picky about charing cables, I only got it to charge using a USB-C to USB-A cable. A normal USB C cable would not charge the battery. Not a big issue but good to know, I though for a while it was defective.
This is a relatively common issue even with phones and other devices that charge via USB-C. Most (if not all) USB-C to USB-C cables have a controller IC inside the plug which if not compatible with the host device it won't charge at all. Some will work normally passing just 5V, but others will need to negotiate with host device before even starting up. As for the battery itself, the idea is very nice ! Only potential problem that I see is the design. The cell voltage is higher than what it outputs so it uses a buck regulator to step down the voltage from 3.7V to 1.2V. Problem can appear if the switching transistor of that regulator gets shorted, the full 3.7V will be passed on the output. This is something I have seen related on this forum on a similar design. Would be curious to see inside, so if you ever intend to open it please share some pictures.
Today I received another two batteries, for the WM-F100III and WM-F202. They had the same nice quality as the previous one although I needed to adjust a little for the F100 to fit properly.
@Rune Lindman For reference please add a link to the product page. A simple search with strings like "WM-100 battery", "WM 100 battery" etc. don't render any relevant results apart from 3D printed sidecars.
name of the store: Jinsuli Factory Store Here is the link to the store on Ali: https://www.aliexpress.com/store/1861114?spm=a2g0o.store_pc_home.pcShopHead_754816797.14 Here is a link to the product, not sure if it will work: https://www.aliexpress.com/item/100...8.0&pvid=4816471e-5ea2-4658-af36-2ce8961e2a6f Let me know if the links above isn't working.