This is a common complaint. We naturally feel inclined to load a template with as much information as possible, but remember that the purpose of the document is not to educate the sales team about the company. Rather, it’s to help them win deals with small bits of critical information.
“When everything is being screamed, nothing is being heard.” Your battlecards should contain specific, up-to-date information that can be used in the field. It should be treated as if it were a Q&A mechanism. If you limit the scope of what belongs on a sales battlecard to this criteria then you’ll be able to keep them clear and concise.