Prismatic vs cluster of 18650

[danphillips]

Newbe asking if any know if there is a major benefit to Prismatic cells vs a cluster of 18650.

If the choice is Prismatic, for a 12v system is it better to get 4 large cells or parallel 8 or 12 cells?

 

[morth]

With a 12v battery made of Prismatic cells, if 1 cell fails, the battery is dead. With banks of parallel cells, cell failures reduce capacity, but the battery is still operational.

 

[grizzzman]

Think about the number of connections using 18650 for the same AH. The likelihood of failure due to connections is much higher.

 

[morth]

I would agree that there are more things to go wrong with large parallel strings, For DIY, prismatic cells are simple to deal with although if you have a spot welder and the pre made fused bus strips, it's pretty straight forward to build parallel strings. Much depends on the use case. For a system where space really isn't a concern, prismatics are much easier to deal with, but they wouldn't be my first choice for an ebike pack. Can always go to 4s 2p (or more) with prismatics and have some redundancy at the cell level. That's part of the fun with this stuff, lots of ways to get from point A to point B