Originally shared on the public FactorioPrints / Factorio School archive (factorioprints.com · factorio.school). Authorship preserved from the public catalog.
This has battery icon showing you visually how much power is in your accumulators and when to get worried. Battery icon is filling up due to the accumulator charge level. When the accumulators run out of juice (less than 10%), you get visual and sound alarm too. Just hook it up into your electric network and you're good to go.
