Tulex
Solar Wizard
After reading some threads about battery issues, I started to think about cell spacing, as too much compression can cause cell damage.
The data sheet for the Eve MB30, which is in the resource area, refers to this.
"Customer shall fully consider the influence of the cell swelling force when designing the module. The product generates expansion force during use, and the expansion force is about 60000 N when the cell capacity attenuates to 60% under the test conditions of 15 mm steel plate + 0.0 mm GAP (the space for cells to expand). Customers shall consider there liability of structural strength in the product design process, and it is suggested to reserve 2.0 mm ~ 2.5mm expansion space while grouping the cells."
That's 5/8" for a row of 8. I've seen everything from compressed cells to taped cells to packed cells. I haven't seen one of those metal box kits in person that everyone is using, or how premade batteries are made, but I can't imaging there's that kind of room. I've only really heard that you have to have a divider to prevent the cells from touching, and now many cell suppliers are shipping with a thin plastic sheet to put between them.
Obviously this is a huge concern as a more likely cause of battery failure. Over compression causing oozing, and constant flexing of the terminal. So for those who have built using box kits or who have been inside purchased batteries, how is this addressed?
The data sheet for the Eve MB30, which is in the resource area, refers to this.
"Customer shall fully consider the influence of the cell swelling force when designing the module. The product generates expansion force during use, and the expansion force is about 60000 N when the cell capacity attenuates to 60% under the test conditions of 15 mm steel plate + 0.0 mm GAP (the space for cells to expand). Customers shall consider there liability of structural strength in the product design process, and it is suggested to reserve 2.0 mm ~ 2.5mm expansion space while grouping the cells."
That's 5/8" for a row of 8. I've seen everything from compressed cells to taped cells to packed cells. I haven't seen one of those metal box kits in person that everyone is using, or how premade batteries are made, but I can't imaging there's that kind of room. I've only really heard that you have to have a divider to prevent the cells from touching, and now many cell suppliers are shipping with a thin plastic sheet to put between them.
Obviously this is a huge concern as a more likely cause of battery failure. Over compression causing oozing, and constant flexing of the terminal. So for those who have built using box kits or who have been inside purchased batteries, how is this addressed?