I am thinking of using chain and adjustable turnbuckles to strap them together with a wood box type setup similar to yours. the chain will not stretch so much and if it does a few cranks on the turnbuckles will hopefully take care of that. 8 of those battery cells weigh 5.3x2.2x8=93.28 pounds, not including the wood, chain, and turnbuckles.
That sounds like it could work. We found that the straps loosened over time a bit so we tightened them and added some strechy electical tape wrapped around the pack to keep the cells from moving around at all in the pack.
I have 4 of the 280ah cells for a 12v pack, I found an old metal ammo can I am thinking of placing them in after I protect the edges of the battery with ply wood. I have a plan for compressing the cells together from the outside using the inside of the metal can. Wish me luck:'). I like your idea to make handles in the wood. It might be a good idea to run another strap through the handle and around the bottom of the batteries to keep them from possibly trying to slide out.
Great idea about the metal ammo can. I have heard that the aluminum casing of the cells is tied to negative, So electrically insulating the cells from the metal of the ammo can might be worth doing. You were right about a strap over the top. The cells were moving around a bit so I have to had to improve the design with over the top straps.
Nice solid box! Have you noticed a slight bulge on the brand new cells? It seems that when they aren't it means are not new and grade A. By any chance do you know the real max peak current? Could it be something like 400a per 1 min?
My understanding is that the expand and contract according to the state of charge. So charged cells will be a bit more bulged out than uncharged cells. Mine were slightly bulged when received but clearly new. I assume that is due to them having a storage charge on them.
Does depend on power needed but these have a 1c discharge rate and at 280AH that means a 280 amp constant discharge. Not bad at all so at a high SOC (14ish volts) that means that 1 bank can support about 4k RMS (14v x 280 amps).
It looks to me that you did absolutely nothing so far as really compressing the cells. Maybe use metal hose clamps if you want to put pressure on the sides of the cells.
It would seem the growth of the cells will push against each other and the stress will still damage the cells. The cells should be free to move. Buss bars could be replaced with more flexible material to allow movement.
@@SnowyOwlPrepper I have been running for 8 weeks with no sign of stress on the cells. Go through a couple shallow cycles each day... Since the cases are thin aluminum the compression stabilizes the internal elements of the cells.
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I am thinking of using chain and adjustable turnbuckles to strap them together with a wood box type setup similar to yours. the chain will not stretch so much and if it does a few cranks on the turnbuckles will hopefully take care of that. 8 of those battery cells weigh 5.3x2.2x8=93.28 pounds, not including the wood, chain, and turnbuckles.
That sounds like it could work. We found that the straps loosened over time a bit so we tightened them and added some strechy electical tape wrapped around the pack to keep the cells from moving around at all in the pack.
I have 4 of the 280ah cells for a 12v pack, I found an old metal ammo can I am thinking of placing them in after I protect the edges of the battery with ply wood. I have a plan for compressing the cells together from the outside using the inside of the metal can. Wish me luck:'). I like your idea to make handles in the wood. It might be a good idea to run another strap through the handle and around the bottom of the batteries to keep them from possibly trying to slide out.
Great idea about the metal ammo can. I have heard that the aluminum casing of the cells is tied to negative, So electrically insulating the cells from the metal of the ammo can might be worth doing. You were right about a strap over the top. The cells were moving around a bit so I have to had to improve the design with over the top straps.
When should you apply compression? Is it during Low state of charge (contraction) or High SOC (cell already expanded) ? Thanks
Good job !
Thank you! Cheers!
Whats up, Meta Grid. it's particularly enlightening video. thank. :)
My pleasure!
Do u think that plastic strips Will not be Broken by the presure of the espansion ?
They are very strong woven straps.
@@metagrid9453 300kg of expansion force of the batery is on datashet
Nice solid box! Have you noticed a slight bulge on the brand new cells? It seems that when they aren't it means are not new and grade A. By any chance do you know the real max peak current? Could it be something like 400a per 1 min?
My understanding is that the expand and contract according to the state of charge. So charged cells will be a bit more bulged out than uncharged cells. Mine were slightly bulged when received but clearly new. I assume that is due to them having a storage charge on them.
Are these batteries good for car audio?.
Depends how much power you need.
Does depend on power needed but these have a 1c discharge rate and at 280AH that means a 280 amp constant discharge. Not bad at all so at a high SOC (14ish volts) that means that 1 bank can support about 4k RMS (14v x 280 amps).
It looks to me that you did absolutely nothing so far as really compressing the cells. Maybe use metal hose clamps if you want to put pressure on the sides of the cells.
Are you sure you need to compress these cells?
Yes.
It would seem the growth of the cells will push against each other and the stress will still damage the cells. The cells should be free to move. Buss bars could be replaced with more flexible material to allow movement.
Asking for trouble. I the c ells expand an contract nd you prevent that, you can damage the cells
@@SnowyOwlPrepper I have been running for 8 weeks with no sign of stress on the cells. Go through a couple shallow cycles each day... Since the cases are thin aluminum the compression stabilizes the internal elements of the cells.
@@bobcole3852 Everything I have read says that is not true. I have been running this pack for 8 weeks with several cycles per day with no issues.
So lets see 4 x 280ah 3.2 cells = 1120ah 3.2v cells. In series to make 48v is 1120ah x 48v = over 53KWh! Holy crap, you powering a village?
would need 64 cells though
I think he forgot to arrange the cells.