What would be an appropriate suppression system here? That's a lotta batteries all arranged like a boy scout arranges kindling logs for a campfire.

A roof-mounted water tank with a thousand gallons ready to dump into the shed? A drum of baking soda?

Or maybe rebuild the shed out of cinder block and clear any overhanging vegetation?

Maybe this whole setup is on desert dirt with plenty of clearance. The fire plan is "run away and wait."

The fire extinguisher is in the wrong place entirely. If the setup is on fire are you really going to reach _in there_ to grab the extinguisher?

There's no protection over the bus connections. Any falling conductive item is now a spark hazard.

Using spring loaded alligator clips as test leads apparently for monitoring. I hope that's not a permanent configuration.

Everything is bolted down and I see no inline disconnects or even any fusing except on low voltage sections.

There are exhaust fans but I can't tell if there's inlet fans.

From this one picture, which may not be fair, this is not a safe setup. I would feel uncomfortable with this on my property.

Not gonna do you any good if the batteries themselves start going off, but if something else has ignited in the cabinet and the batteries are not yet on fire... you'd be glad to have the extinguisher, I bet

I experienced a 400v DC lithium ion battery catch on fire once, it was very scary. That fire extinguisher won't do much at all, even if it is placed in a more logical spot.

The firemen ended up putting the battery, half melted, into a big drum of water and it hook hours to cool off. The concrete was still warm to the touch where it burned for ~30 hours after the situation was sorted out.

The smoke was just absolutely unbelievable. Made me reconsider buying an EV. That fire was no joke.

The MV contactor wasn't even closed, it had 24v powering it for the internal cell balancer from the vendor, that was it.

It's definitely now in the wrong spot. I assume that once upon a time there was one rack against the wall, and it was only slightly irresponsibly placed, and now there are two racks and hey kids, heat rises.

The extinguisher should be directly inside the door so as not to attract someone to traverse farther into the building without an escape plan.

Of course if he did so then there would be no extinguishers in the picture and then we would also bitch about it.

The only purpose of a fire extinguisher is to allow you to get out. They do not contain enough water to adequately put out any real life fire (especially not an electrical one like this).

If he can't reach to grab it because it's too hot, he should have already left.