I'm interested in hearing practical tips/tricks/ideas for keeping empty batteries separated from the charged ones in your camera bag. My DSLR batteries came with a cover with a small opening that could be placed either over the blue or grey colored patch on the battery label, thus providing a visual clue. My mirrorless batteries didn't come with such covers so we need creative options there. Suggestions I've seen from other mirrorless shooters include putting a rubber band around the battery once it's been charged or storing charged and empty batteries in a zip lock bags with different colored labels. Any other interesting solutions?