o00scorpion00o
Well-known member
Hi everyone,
I'm having a discussion on another forum about charging observations on the Leaf while using the DC charger.
I got a few questions and I appreciate your time and efforts put into this.
1: Is charging controlled solely by the Charger, BMS or both ? what I mean is, I know the ramp down phase in the transition from CC to CV is controlled by the charger/BMS however , we were discussing why the 30 Kwh charges in the same time to 80% as the 24 Kwh and my interpretation of it was that the larger battery takes longer to get from CC to CV and that it's not controlled by Nissan tweaking the BMS instructions for the new battery to the charger and allowing more power to be sent to the battery.
You can clearly see the power reduce gradually as the battery % increases, is this because as the voltage rises in the battery it no longer demands the power from the charger ? Or is it completely controlled by the charger ?
2 : we know heat and cold have an effect on charge times and this can increase/decrease the internal resistance. I have read in a paper from the University of University of Wisconsin Milwaukee via this link http://dc.uwm.edu/cgi/viewcontent.cg...46&context=etd that it's the internal resistance that causes the reduced current that can flow to the battery caused by this increased IR, so this I assume is not controlled by Nissan or the charger/BMS and a result of the effects of cold on the chemistry ? or is the battery temp data sent to the charger and this tells it to reduce the power because of the cold battery ? There are other sites/studied done on this which conclude that increased IR increases charge times.
I have observed reduced current that could be pulled when I was riding my high powered E-Bike on LiPo and much increased voltage sag and poorer acceleratuion in cold weather compared to warm. I did not notice effects of charging because my charger was pretty low powered in the first place. A similar effect I observed when the battery was worn only this time I could continue to pull the max current but the voltage sagged horribly and I could not get the capacity from the pack unless riding very gently.
So my LiPo pack had no BMS and all that was between that and the battery was the motor controller which did have a LVC but obviously no cell monitoring.
3 : An effect people are noticing with older leafs is increased charge times on the fast charger due to an ageing battery and reduced regen, one person on this forum with a 2012 leaf and 30 odd K miles noticed he can't get more than 35 Kw from the DC charger compared to mine pulling 50 Kw on my 2015 Leaf (charger KW display). He has noticed some loss of capacity around 10% compared to 0 loss reported by leaf spy for me over 14,000 Miles.
So is this internal resistance the cause of the battery not demanding the power because the power simply can't be delivered to the battery as has been reported on other sites and University papers or is it the charger controlling the current sent to the battery by monitoring the internal resistance of the battery as it ages and adjusting the current accordingly ?
I appreciate your replies .
I'm having a discussion on another forum about charging observations on the Leaf while using the DC charger.
I got a few questions and I appreciate your time and efforts put into this.
1: Is charging controlled solely by the Charger, BMS or both ? what I mean is, I know the ramp down phase in the transition from CC to CV is controlled by the charger/BMS however , we were discussing why the 30 Kwh charges in the same time to 80% as the 24 Kwh and my interpretation of it was that the larger battery takes longer to get from CC to CV and that it's not controlled by Nissan tweaking the BMS instructions for the new battery to the charger and allowing more power to be sent to the battery.
You can clearly see the power reduce gradually as the battery % increases, is this because as the voltage rises in the battery it no longer demands the power from the charger ? Or is it completely controlled by the charger ?
2 : we know heat and cold have an effect on charge times and this can increase/decrease the internal resistance. I have read in a paper from the University of University of Wisconsin Milwaukee via this link http://dc.uwm.edu/cgi/viewcontent.cg...46&context=etd that it's the internal resistance that causes the reduced current that can flow to the battery caused by this increased IR, so this I assume is not controlled by Nissan or the charger/BMS and a result of the effects of cold on the chemistry ? or is the battery temp data sent to the charger and this tells it to reduce the power because of the cold battery ? There are other sites/studied done on this which conclude that increased IR increases charge times.
I have observed reduced current that could be pulled when I was riding my high powered E-Bike on LiPo and much increased voltage sag and poorer acceleratuion in cold weather compared to warm. I did not notice effects of charging because my charger was pretty low powered in the first place. A similar effect I observed when the battery was worn only this time I could continue to pull the max current but the voltage sagged horribly and I could not get the capacity from the pack unless riding very gently.
So my LiPo pack had no BMS and all that was between that and the battery was the motor controller which did have a LVC but obviously no cell monitoring.
3 : An effect people are noticing with older leafs is increased charge times on the fast charger due to an ageing battery and reduced regen, one person on this forum with a 2012 leaf and 30 odd K miles noticed he can't get more than 35 Kw from the DC charger compared to mine pulling 50 Kw on my 2015 Leaf (charger KW display). He has noticed some loss of capacity around 10% compared to 0 loss reported by leaf spy for me over 14,000 Miles.
So is this internal resistance the cause of the battery not demanding the power because the power simply can't be delivered to the battery as has been reported on other sites and University papers or is it the charger controlling the current sent to the battery by monitoring the internal resistance of the battery as it ages and adjusting the current accordingly ?
I appreciate your replies .