Powerwall shelf building on the cheap

[harrisonpatm]

Everybody's powerwall build is going to be different, and everyone's budget is different, but I thought I'd bring this up. I'm planning my build in modular packs using the 4x6 18650 cell holders, on shelves for each series. Turns out reclaimed pallet boards are exactly the depth needed for the 4x6 packs. For 4 cells deep, not 6, though there are various pallet sizes and some of the wider boards probably could accommodate 6 cells deep. And it's not hard to find used pallets for free, if you don't mind breaking them apart yourself. Just wanted to share for other people that could use that information, since it's a great option for a build on a budget, not to mention fits in with the theme of "second life."

 

[OffGridInTheCity]

Some worry about wood burning. But I must confess that even though shelves have a metal framework the batteries are sitting on pressboard shelves

 

[harrisonpatm]

Some worry about wood burning. But I must confess that even though shelves have a metal framework the batteries are sitting on pressboard shelves

I've also heard elsewhere that in the case of disastrous thermal runaway, an all-metal framework will still burn at lithium fire temps; just a bit slower. I have no facts to back that up, but even if you build an all-wood storage, it'd still be a good idea to throw some insulation in there as well, which may also have fire retardant properties.

 

[Wolf]

There is nothing wrong with a healthy cautious approach to building a Li-Ion battery enclosure out of any flammable material i.e. wood.
My storage system is built of wood. 3/4 plywood to be exact. Also treated with a class A fire retardant in my case "Master Flame" Spray on application.
Now doing a bit of research and according to Erie Insurance quoting a CNET study/article the chance of a lithium fire are 1 in 10 million.
The CDC puts your odds of being struck by lightning in a given year at around 1 in 500,000.
On the other hand with Mega Millions, your odds of winning are about 1 in 176 million.
If you're playing a single-state lottery, like the California Super Lotto, your odds increase — to 1 in 42 million.
So your odds are better to get struck by lightning, not a pleasant thought, and possibly terminal, than winning the lottery or a lithium fire..
Those "fire" odds of course are increased by a nonchalant attitude with using recycled Li-Ion cells. My philosophy on Li-Ion harvesting has matured to the point where I verify every single cell at least 5 times before I feel comfortable using it in my packs/battery. Is that overkill? Maybe, but I sleep well at night knowing the "numbers" of each and every one of the 4480 18650 Li-Ion cells in my 14s80p X 4 Battery

A good BMS that has data collection, adjustable to our desires, has safety features, and a data stream for recording parameters that we can
examine on a consistent basis for any anomalies to keep our Li-Ion batteries within the odds to favor us, is of course a must.
Wolf

 

[harrisonpatm]

There is nothing wrong with a healthy cautious approach to building a Li-Ion battery enclosure out of any flammable material i.e.wood.
My storage system is built of wood. 3/4 plywood to be exact. Also treated with a class A fire retardant in my case "Master Flame Spray on application.
Now doing a bit of research and according to Erie Insurance quoting a CNET study/article the chance of a lithium fire are 1 in 10 million.
The CDC puts your odds of being struck by lightning in a given year at around 1 in 500,000.
On the other hand with Mega Millions, your odds of winning are about 1 in 176 million.
If you're playing a single-state lottery, like the California Super Lotto, your odds increase — to 1 in 42 million.
So your odds are better to get struck by lightning, not a pleasant thought, and possibly terminal, than winning the lottery.
Those "fire" odds of course are increased by a nonchalant attitude with using recycled Li-Ion cells. My philosophy on Li-Ion harvesting has matured to the point where I verify every single cell at least 5 times before I feel comfortable using it in my packs/battery. Is that overkill? Maybe, but I sleep well at night knowing the "numbers" of each and every one of the 4480 18650 Li-Ion cells in my 14s80p X 4 Battery

A good BMS that has data collection, adjustable to our desires, has safety features, and a data stream for recording parameters that we can
examine on a consistent basis for any anomalies to keep our Li-Ion batteries within the odds to favor us, is of course a must.
Wolf
View attachment 27365
View attachment 27366 View attachment 27367

Excellent info thank you. I'll look up the fire spray.