Experience, they say, is the best teacher. But what happens when you don’t have a lot of experience?

“We learned a lot,” said Chandler Battalion Chief Keith Welch after dealing with the city’s first major lithium-ion battery fire.

Welch said the one thing they knew about lithium battery fires before this one: handle with care. That’s because of a 2019 incident in Surprise that sent eight Peoria firefighters to the hospital.

So, Chandler Fire was slow and deliberate in dealing with a lithium battle fire at a Salt River Project battery storage facility owned by AES Corporation south of the Loop 202 on 54th Street.

“Our strategy on [April 29] to shut off the sprinklers and further ventilate the building paid off,” Welch said.

It took a lot of time and patience to get to that point.

The fire was first noticed at around 11 a.m., April 18, when the building’s sprinkler system went off. Chandler Fire responded, but did not see any flames or immediate danger of it spreading.

Welch said one of the lessons learned from that Surprise blaze was not to rush in. A sudden change of air entering the building could lead to toxic gas, overwhelming firefighters.

So, they let the fire burn while the sprinklers constantly poured water on it, keeping it from spreading. Four days later they staged a voluntary evacuation of the area. The worry was not flames but fumes. They sent in a robot to open a door to the building to help start ventilating it.

They continued to monitor the building to make sure the fire was not growing.

Again, they were patient. They waited more than a week before staging another voluntary evacuation of the area. They ran some ducts to the building to ventilate it further, then after everyone was a safe distance away, they shut off the sprinklers.

The best-case scenario of no growing fire happened. After 48 hours of monitoring, Welch said they were able to turn it back over to the owner so they could start dealing with the aftermath.

The ventilation was key because lithium batteries can build up dangerous gases.

“What we’re looking at airing out is going to be some gases that build up in there, like some hydrogen gases, hydrogen sulfides, CO [carbon monoxide], different things of that nature that are very flammable and dangerous to us,” Welch said.

He said they were lucky because the fire suppression system did its job.