Is it OK to keep my Bose sound dock plugged in all the time except when I’m using it outside? The reason I ask is that lately I’ve noticed the yellow light come on after it’s been plugged in and already fully charged. This was last night. This morning the light was off and I took it outside to play it and it stopped after an hour and a half. I had to plug it in to a portable generator to get it to work. So, I’m thinking that there’s something wrong with the battery.
Generally speaking, you don’t want to keep lithium-ion batteries fully charged all the time, because that cuts into their service life. The lithium-ion chemistry (I am taking a guess at that is what is inside the Sound Dock) is happiest between 20% and 80%.
So your battery is likely already low on health.
There are several somewhat different products marketed by Bose as sound dock so it would be good to know which one you have. Some (most?) use a proprietary format and you would need to buy it from Bose.
Sometimes it is possible to replace the cells inside the battery module if you are so inclined. Most battery modules use standard sized batteries like the popular 18350 or some cousin. I have done this for devices that don’t have a modular battery and it usually involves the use of a soldering iron and oftentimes some case cracking.