There's nothing to worry about unless that light runs down batteries much faster in a way that is causing a problem for you. All flowlights get a bit warm when the battery gets low. Mark the battery and switch it around the next time after charging to see if it's the battery or the light.
If you find that it's the light, and you notice that it doesn't last as long as the other lights, you can send it back and we will replace that light.
If you have any questions, please feel free to contact us!