I think they meant 'batteries as a system', not the individual cells and grid tied batteries have a very large amount of electronics to charge, discharge and protect the batteries.
Is there evidence that batteries as a system are more vulnerable to EMP than the current electric grid? More so, is there evidence that EMP is a viable threat? Ensure the battery grid has the same uptime or better than the current grid and call it a day.
Also, thank you for the reminder of the guidelines: "Please respond to the strongest plausible interpretation of what someone says, not a weaker one that's easier to criticize. Assume good faith."
