I have the following keyboard, RT-UMK-100-BT. It suddenly wouldn't charge and as I didn't use it very often it got shelved until I had a need for it again. I opened it up to find the battery all swollen so I presume that's why it doesn't charge anymore. I cant find out what exact battery it takes. It does have 5c 300ma on the back though. Anyone got any idea what battery I could use.
Pretty much everything is lithium ion these days, so you just need to find one that fits. Measure it and check out whatever your local version of digikey or mouser is.
I'm not sure if this would be better as a tech support thread, but anyway. The manual for the part does state lithium ion, so that's certain. The 5c will be the charge rate allowable for that cell, so could apply to any lithium ion cell. If you can supply dimensions or a photo that would certainly help?
I cant find it again now but some where else mentioned the specs to be 3.3v 80ma. Edit...Just read this in the manual Power supply: Rechargeable polymer Lithium-ion battery Charging voltage: 4.4V ~ 5.25V Charging current: 300mA Sleeping current class1: 30uA Operation voltage: 3.7V The dimensions are 2" x 1.25" or 50mm x 22mm. Its quite swollen. Battery3 by CrapBag posted 11 Sep 2020 at 11:14
Now the 300ma is pretty much how long its going to give charge for right? So if I purchased a lower rated one, say 200ma then it just wouldn't power the keyboard for as long. I can get a 200ma one for £2.27 or the full fat 300ma for £8.99. Its only going to be for occasional use (inputting text on my bedroom smart tv) and it used to last for ages anyways. I don't even know if it still works as it might not be the battery so a £2 punt seems the better option.
