Last paragraph of the above article:
“If the battery box is intact and there are no exposures, the best solution is to simply wait for the battery to burn itself out, then extinguish the remaining class A fire. While this strategy is not ideal – and not one favored by aggressive, proactive and eager firefighters – it’s really the best approach. It should only take an hour for the battery to burn itself out. The alternative will be to continually dump water on the vehicle for 6 to 8 hours.”
Depending on location, adding flammables to it might help speed it up to less than an hour - a cord or two of firewood, some magnesium, maybe some phosphorous.