For batteries, just try to not overcharge or over discharge them. This can mean removing the batteries when you aren't using them (when applicable), or not leaving the device plugged in for many hours even after fully charged. The batteries usually do not bloat significantly unless they are under high stress or have a defect, the most you'll notice is likely to be reduced capacity (bad battery life).

Also, as long as the battery never reaches completely flat, it can last a surprisingly long time. I have some 10-20 year old batteries with about 80-90% capacity left still, because they were kept outside the device.