How to turn off charging on my iPod dock??

Hi! I have a silver Sony ICF-CS15iP iPod dock from around 2010/2011 and I use it with one of my few iPods, though I hate how it always is charging them when I dock one of them. It wears out the battery when I have it docked for a while and I'm trying to not have any of them catch on fire. Is there a way to turn it off? Even not on my dock, did any of the iPod docks available back then have a option to turn off charging??

Thank you!!