LifePo4 Charge Performance
Thinking seriously about replacing our two GC2's with a pair of 100ah LifePo4's. Hearing a lot of chatter about how lithiums accept a charge much quicker than lead cells. Very familiar with how ou...
Forum Discussion
Internal Resistance changes with SOC and with Temperature. It changes to different degrees between types of battery chemistry and construction.
I am finding info on how that works with discharge current abilities but nothing yet on how that affects charging currents for different types of battery at different temperatures.
LFP is notable for how its IR is higher at low SOC. I think this is why they don't want you to go to "zero" with them. It may be that they fudge where "zero" is. Also they might fudge where "full" is with some battery monitors.
EDIT--I see Itinerant1's sig has his bank in its "usable" amount. I don't do wh, but that would relate to his 500AH somehow :)
It comes back to the question why they have such high discharge rates and low charging rates, when you would think they would be the same.
Note that I cannot confirm that SiO2 can't take higher charging rates and will just throttle that down to what they can take. A couple of info guides said they can be charged at high amp rates but not for a long time. How long was not defined. So I personally don't do it since I cannot afford to keep buying new ones!.
With LFP they talk about resting the battery after a full recharge so it works best on the next discharge. It is not clear it has to do with balancing or just how LFP cells work.
I don't see where BMS controls the charging current, even the expensive ones. they do have cut-offs for excessive currents and voltages, but I don't see where they "dial" the current to match the acceptance rate at various temps and SOCs. Seems like that is up to you not to use a charger that cranks out too many amps.
https://batteryuniversity.com/learn/archive/how_does_internal_resistance_affect_performance
Scroll down past the talk time part to the good stuff.
I am finding info on how that works with discharge current abilities but nothing yet on how that affects charging currents for different types of battery at different temperatures.
LFP is notable for how its IR is higher at low SOC. I think this is why they don't want you to go to "zero" with them. It may be that they fudge where "zero" is. Also they might fudge where "full" is with some battery monitors.
EDIT--I see Itinerant1's sig has his bank in its "usable" amount. I don't do wh, but that would relate to his 500AH somehow :)
It comes back to the question why they have such high discharge rates and low charging rates, when you would think they would be the same.
Note that I cannot confirm that SiO2 can't take higher charging rates and will just throttle that down to what they can take. A couple of info guides said they can be charged at high amp rates but not for a long time. How long was not defined. So I personally don't do it since I cannot afford to keep buying new ones!.
With LFP they talk about resting the battery after a full recharge so it works best on the next discharge. It is not clear it has to do with balancing or just how LFP cells work.
I don't see where BMS controls the charging current, even the expensive ones. they do have cut-offs for excessive currents and voltages, but I don't see where they "dial" the current to match the acceptance rate at various temps and SOCs. Seems like that is up to you not to use a charger that cranks out too many amps.
https://batteryuniversity.com/learn/archive/how_does_internal_resistance_affect_performance
Scroll down past the talk time part to the good stuff.
