Hopefully 98% in that example, thoughYes there is an actual equation this is not just made up. It's ( actual remaining capacity AH/ Rated AH capacity) for example 98ah/100ah= 0.98%.
Hopefully 98% in that example, thoughYes there is an actual equation this is not just made up. It's ( actual remaining capacity AH/ Rated AH capacity) for example 98ah/100ah= 0.98%.
Literature says 80% SOH at 7000 cycles.Assuming it actually means anything, you'll be at 80% SoH @ 4180 cycles. Why aren't you happy?
Literature says 80% SOH at 7000 cycles.
Good point. I ignore check engines lights too.I Wouldn't worry about the SOH reading, until the battery starts smelling like peanut butter.
What makes a battery smell like peanut butter?
Absolutely nothing, unless you smear peanut butter on it.
Check engine lights are real.Good point. I ignore check engines lights too.
Typically this value is calculated based on observed capacity and nominal capacity (that is, a relationship between how much capacity is actually observed by the BMS and how much capacity the battery pack started off with when new) and the Internal Resistance of the pack.
Good point. I ignore check engines lights too.
SoH definition and implementation is up to the manufacturer. I have an Orion BMS. My SoH was dipping down quite a lot (by 10%+) ...
Could you comment on how you determined you had high resistance developing between bus bars and cell terminals?as a result of high IR developing between the bus bars and cell terminals. Once I fixed that,
I’m starting to plan for a new system which will push my 560W 8S2P LiFePO4 battery harder than it’s been pushed over it’s first 3 years.my SoH has remained at 99% (450 cycles so far). From their site, this is what they define as SoH:
I personally wouldn't pay attention to any SoH differences less than 1%. To really know, do a capacity test.
So a 280Ah cell might drop to 252-266Ah after year one but should then remain close to that for the next few years?Possibly toward the end, below 50% for example.
Even though it is a different chemistry, my experience with EV batteries is that there is a steep initial degradation of 5-10% in the first year, then they plateau off for the next seven or eight. That is the longest I have owned an EV. I am still using some ten year old Nissan Leaf modules that still have 60-70% of capacity but I have no knowledge of their prior ownership,
So a 280Ah cell might drop to 252-266Ah after year one but should then remain close to that for the next few years?
I’m 3 years in and planning to tune up my battery as appropriate this winter, so interested in any advice for how to do so…
Could you comment on how you determined you had high resistance developing between bus bars and cell terminals?
And how did you go about ‘fixing’ that?
I’m starting to plan for a new system which will push my 560W 8S2P LiFePO4 battery harder than it’s been pushed over it’s first 3 years.
Just looking at how much battery voltage drops when charge current or discharge current changes abruptly, I’m suspecting I may have some higher-than-ideal resistance between bus bars and aluminum cell terminals.
So I’m in the market for any advice regarding how to determine which connections may need improving and best practices to do so…