thunderstorm80
1 kW
- Joined
- Mar 29, 2016
- Messages
- 383
Hi,
Can anyone explain why the huge differences?
For example, MG1 cells can be charged at ~0.5C but discharged at ~3C with no problem.
Further more, many LiPo's (or as I call them - gunpowder ) can be discharged at a whopping rate of 90C but only charged at 0.5C~1C or so.
Chemistry is not my strong side, but from what I was able to gather pieces of information from the internet - it's about the ions that move around during charge/discharge, and that during the final stages of a charge, the ions start to "compete" over the remaining sites making the cell less responsive/reliable if you try to force a fast charge rate at this point which would result in heat/outgassing/etc.
Another source also suggests that during an initial charge when the %SOC is around 0%, you are allowed to inject a much larger (than the spec's) C-rate up to the 70% SOC mark, more or less, due to the same reason.
I would assume that the same would be valid for discharge? For the initial discharge at 90-100% SOC you can implement the fully allowed discharge current, but from like 30% or so you should be limiting your discharge C rate more and more as you approach the empty cell?
Would be nice if someone can turn this mesh of information/different sources to a more clear picture.
Can anyone explain why the huge differences?
For example, MG1 cells can be charged at ~0.5C but discharged at ~3C with no problem.
Further more, many LiPo's (or as I call them - gunpowder ) can be discharged at a whopping rate of 90C but only charged at 0.5C~1C or so.
Chemistry is not my strong side, but from what I was able to gather pieces of information from the internet - it's about the ions that move around during charge/discharge, and that during the final stages of a charge, the ions start to "compete" over the remaining sites making the cell less responsive/reliable if you try to force a fast charge rate at this point which would result in heat/outgassing/etc.
Another source also suggests that during an initial charge when the %SOC is around 0%, you are allowed to inject a much larger (than the spec's) C-rate up to the 70% SOC mark, more or less, due to the same reason.
I would assume that the same would be valid for discharge? For the initial discharge at 90-100% SOC you can implement the fully allowed discharge current, but from like 30% or so you should be limiting your discharge C rate more and more as you approach the empty cell?
Would be nice if someone can turn this mesh of information/different sources to a more clear picture.