Headrc
Member
- Joined
- Jan 27, 2018
- Messages
- 265
I am going to finally launch myself into building a larger powerwall battery. It is going to be a 14S24P using new Boston Power Swing 5300batteries that I have. I will also be installing a Batrium BMS on it and plan to lay it out so at a later date if I want to, I can more 14S24P's that can be wired in parallel and use the existing Batrium BMS setup. I am going to fuse the battery at the cell levelfor safety reasons, but the batteries are all new so I am trying to decide on the size of fuse. I want the safety but also don't want to limit the battery too much if the load calculation increases in the future. Each cell is capable of 13A continuous discharge so this is potentially a lot of current capability. Total aH is 127.2 giving me around 6.6kWh at the nominal voltage of 3.7 and more when charged up.
So right now the questionis the size of fuse .....I see what everyone is doing when utilizingreclaimed cells ...but what about new cells like the ones I am going to use? Current load calculation is around 60amps. Just using this means 2.5A per cell which the batteries definitely can handle.But what if I go to a larger load calculation in the future and don't add another pack in parallel yet? If I put a fuse that blows at 2.5Aat the cell level, then a larger load cannot be handled even if the batteries themselves can handle it. But if I put a fuse at the cell level that is really in the range of the 13A these cells are capable of I may not have the safety level for unknown disasters we all want to be prepared for.
Thoughts on this are appreciated. As I move ahead on the project I will update with pictures and progress.
So right now the questionis the size of fuse .....I see what everyone is doing when utilizingreclaimed cells ...but what about new cells like the ones I am going to use? Current load calculation is around 60amps. Just using this means 2.5A per cell which the batteries definitely can handle.But what if I go to a larger load calculation in the future and don't add another pack in parallel yet? If I put a fuse that blows at 2.5Aat the cell level, then a larger load cannot be handled even if the batteries themselves can handle it. But if I put a fuse at the cell level that is really in the range of the 13A these cells are capable of I may not have the safety level for unknown disasters we all want to be prepared for.
Thoughts on this are appreciated. As I move ahead on the project I will update with pictures and progress.