ERA are designed to disrupt penetrators travelling at >1500m/s.
To do this, the explosive element in the ERA has to react in the millisecond (or less) where the penetrator can still be influenced and disrupted. To give perspective, a 1m long penetrator, even slowed to 1,000m/s, is through a point in 1millisecond (0.001sec}
The Hi-Ex used in ERA typically has a det velocity of 7,000-9,000m/s.
A battery explosion otoh, is most definitely sub-1,000m/s. Slower than the penetrator, which means a significant portion of the penetrator, if not all, will be past before the battery-ERA can react.
The best bet is if the materials in a battery pack can be assembled in a manner that functions as a NERA. If it even can be.