By referring to the packs as interchangeable, it sounds like you are saying that you put the 62 cell packs into strings along with the 50 cell packs?OffGridInTheCity said:I've stumbled into the idea of building to a specific ah per pack rather than specific number of cells.
I shoot for 130ah per pack. In the early days I bought 2100mah cells it took 62'ish to make 130,000mah. Lately I've been buying2600mah cells where it takes 50 to get to 130,000mah. But all mypacks are the same physical size - so in terms of mah they are interchangeable.
Oz18650 said:Common design is that each cell should not be providing more than 500ma of current.
crashintoty said:Interesting. I was starting to think 80p was the go to because it's as big as you can physically go before the pack started suffering structural issues.
Good point about the physical location of the battery - I don't even have shelves to hold 80p packs (16" to 18" deep).
Oz18650 said:Common design is that each cell should not be providing more than 500ma of current.
Why is 500mA the suggested limit? Is this for continuous or for burst/surge/spike? If the former, what is the suggested max for burst/surge/spike?
Oz18650 said:By referring to the packs as interchangeable, it sounds like you are saying that you put the 62 cell packs into strings along with the 50 cell packs?OffGridInTheCity said:I've stumbled into the idea of building to a specific ah per pack rather than specific number of cells.
I shoot for 130ah per pack. In the early days I bought 2100mah cells it took 62'ish to make 130,000mah. Lately I've been buying2600mah cells where it takes 50 to get to 130,000mah. But all mypacks are the same physical size - so in terms of mah they are interchangeable.
If so, the current per cell (stress on cells) will be higher for the 50 cell packs.
Common design is that each cell should not be providing more than 500ma of current.
Using that number, your 62 cell packs could comfortably deliver 31A of current.
If you have a string of 62P cells and you substitute in a 50P cell pack and draw 31A from the string, you will be taking 620ma per cell from the 50 cell pack.
You're saying thatall cells (50 + 62 = 112 in this example) deliver the same ma/cell to meet the overall load on the battery - correct? I'm asking so I can correct my own thinkingdaromer said:All the cells are in parallel so the 50p pack doesnt get more current per cell than the 62p pack gets unless you fucked up...
Think someone missed a lesson in ohms law there
Once again dont overcomplicate things here. There aint no magic behind or hidden things ongoing
crashintoty said:Also, would a 1s300p config (20 cells deep x 15 cells wide) be physically unmanageable and/or a b*tch to troubleshoot/maintenance or should I simply throw four 1s80p packs together in parallel and call it a day??
crashintoty said:Also, would a 1s300p config (20 cells deep x 15 cells wide) be physically unmanageable and/or a b*tch to troubleshoot/maintenance or should I simply throw four 1s80p packs together in parallel and call it a day??
mike said:crashintoty said:Also, would a 1s300p config (20 cells deep x 15 cells wide) be physically unmanageable and/or a b*tch to troubleshoot/maintenance or should I simply throw four 1s80p packs together in parallel and call it a day??
No, not at all. This is exactly what I'm doing and it works GREAT. I even wrapped mine with heat shrink and the compression of the shrink creates a rock solid pack.
There's some info in this video...
daromer said:All the cells are in parallel so the 50p pack doesnt get more current per cell than the 62p pack gets unless you fucked up...
Think someone missed a lesson in ohms law there