these look bigger than 105's to me. not sure, but look at post # 17 pic 131500 .To put 2 cells side by side I assume 105ah cells. . Someone else can calculate the total capacity.
Assuming you are right the insulation issue was between the battery and the breakerLooks like either the insulation melted off and arced into the shelf support because the battery was still on or the insulation was frayed as you say and shorted into the shelf and ate away at the metal.
Someone better at guessing size from looking will have to take a stab it the size thenthese look bigger than 105's to me. not sure, but look at post # 17 pic 131500 .
93 x 0.550kW = 51.1kW PV wow!
(i wish i had that much!)
The 2nd post shows he had 16 cells per shelf 2 rows of 8 if they are 280Ah batteries that about 12lbs each I'm rounding up that would be 192 lbs on each shelf. I have put well over 600 lbs. on 3/4 inch particle board shelves are built like these without any issue of collapse. I know the ones that are sold at Home Depot, and use to be sold at Costco both had 1200 lbs ratings. I don't believe these ratings are bogus they would be liable they are testing these shelves. I have even had oil soaked into mine had a 350 small block Chevy engine sitting on it for 5 years.So, asked my soon to be brother-in-law a few questions and showed him the pictures. He is a fireman down in texas with a medium sized town. He agrees with the shelf collapse theory from what he can see.
And as a side note he says the extinguishing agent was likely class D powder to smother the active flames. Seems Like that could be a way to build a self extenguisher based on some retaining wire or thin rope with a bottom opening bin above the battery bank.
OP is in Australia, his suppliers are not the same as your suppliers. the shelf material may be thinner - we don't know.The 2nd post shows he had 16 cells per shelf 2 rows of 8 if they are 280Ah batteries that about 12lbs each I'm rounding up that would be 192 lbs on each shelf. I have put well over 600 lbs. on 3/4 inch particle board shelves are built like these without any issue of collapse. I know the ones that are sold at Home Depot, and use to be sold at Costco both had 1200 lbs ratings. I don't believe these ratings are bogus they would be liable they are testing these shelves. I have even had oil soaked into mine had a 350 small block Chevy engine sitting on it for 5 years.
I think something got hot his circuit protection didn't work started a small fire that caught the wood above it once that glue in the wood starts to fuel the fire it gets hot quick.
This is what I used on all 6 wood sides and structure builds inside my solar trailer .. 35 buck a quart bottle …they say two coats are better than one….I used 7 coats….let it soak in and dry , then repeat as much as you want …Product name?
Ok, I did the math for 5 batteries, 16 cells, 304ah = 24302ahSomeone better at guessing size from looking will have to take a stab it the size then
I was never good at higher math like this, which is why I wanted someone else to do it. I can feel this being my next reading topic.At 3.4V?
For 48V battery, 5 batteries x 304 Ah = 1520 Ah.
OP said 5 rows of shelves each shelf had 2 battery banks that is 10 battery banks lets assume 304ah batteries wired in series to get 51.2 V each shelf grand total of 3040 amps. Around 145-150k watts of power. That's a lot of power in a garage .I
I was never good at higher math like this, which is why I wanted someone else to do it. I can feel this being my next reading topic.
Testament to the relative safety of LFP cells, even with that much capacity, if that was NCM they'd prob still be trying to put the fire out.OP said 5 rows of shelves each shelf had 2 battery banks that is 10 battery banks lets assume 304ah batteries wired in series to get 51.2 V each shelf grand total of 3040 amps. Around 145-150k watts of power. That's a lot of power in a garage .
It is a little unclear but some of their other posts lead to thinking this is pretty recently set up, perhaps Oct-Nov 2023. Meaning it isn't old, and may not have been running (or not at full scale) for all that long. There are posts about buying 93 550W panels, but It is not clear how many were installed or if this was done in stages.Over time conditions that the batteries were stored in allowed corrosion.
I wondered about this as well:Due to the fact that DC can maintain an arc across a larger gap once it gets started is it possible the shunt opened up under high load and an arc continued to burn until the wood caught fire? I know this can be a problem with solar panel disconnects where open it up under high loads the breaker arcs and starts a fire.