Battery information in the instrument cluster

L

Luis Abreu

Member
Hello guys.

Another stupid beginner question: the battery information shown in the main instrument cluster refers to which capacity? Driving (28.9 kwh, if I'm not mistaken)? Or the full battery capacity (32 kwh)? I was under the impression that it should be about the driving capacity, but comparing the charged % with the values shown on the ev charger, it seems like it references the full battery capacity...unfortunately, the manual seems not to mention anything about this...
 
I think it has to be the driving capacity. The energy put in by your charger will always be more than the energy added to the battery because charging isn't 100% efficient. That's probably why you are seeing the discrepancy.
 
That would definitely make sense, but looking at the % difference (before and after) vs kwh shown on charger, we're talking about a 2kwh diff... ia that a normal value for looses for 1 h charging from a 11kwh hour charger?
 
That's a big difference. What climate are you charging in? If it's very warm or cold, I could see the car using a decent amount of energy to condition the battery, because it has to use the AC or heater to stabilize the battery temperature for charging. What kind of charger is this? L3 or 3-phase L2?
 
In that case, the inverter in the Mini is definitely eating up some energy when converting from AC to DC for the battery. I'd be surprised if it was less than 95% efficient though. The watt-meter in the charger might just not be very accurate.
 
Luis Abreu said:
Another stupid beginner question: the battery information shown in the main instrument cluster refers to which capacity? Driving (28.9 kwh, if I'm not mistaken)? Or the full battery capacity (32 kwh)?
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A Li-Ion battery doesn't like to be overcharged or completely discharged. The difference between the 32.6 kWh and 28.9 kWh is the space at the top and the charge at the bottom the software reserves to prevent those things from happening. So when your MINI Cooper SE stops charging, you've probably got more than 28.9 kWh, but certainly less than 32.6 kWh. That way, regen braking after you leave the charging station at the top of that steep hill won't overcharge the battery.

Later, when your MINI coasts to a stop with an "empty battery," it's not really completely discharged. The software chooses to leave you stranded at that spot rather than taking you just a little further and damaging the battery by completely discharging it.

MINI knows you would be frustrated if the charging gauge on the instrument panel never indicated a full battery, so it indicates full when the headroom it has reserved to prevent overcharging has been reached.

I don't know how much headroom the MINI reserves (it could be very small). I guess that when regen braking causes the battery charge to reach the software-limited headroom the MINI just stops all regeneration and lets the brake discs do all the braking. Does the brake-pedal feel change suddenly when the headroom threshold is reached? If my MINI Cooper SE ever gets here, I'll have a chance to find out.
 
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insightman said:
A Li-Ion battery doesn't like to be overcharged or completely discharged. The difference between the 32.6 kWh and 28.9 kWh is the space at the top and the charge at the bottom the software reserves to prevent those things from happening. So when your MINI Cooper SE stops charging, you've probably got more than 28.9 kWh, but certainly less than 32.6 kWh. That way, regen braking after you leave the charging station at the top of that steep hill won't overcharge the battery.

Later, when your MINI coasts to a stop with an "empty battery," it's not really completely discharged. The software chooses to leave you stranded at that spot rather than taking you just a little further and damaging the battery by completely discharging it.

MINI knows you would be frustrated if the charging gauge on the instrument panel never indicated a full battery, so it indicates full when the headroom it has reserved to prevent overcharging has been reached.

I don't know how much headroom the MINI reserves (it could be very small). I guess that when regen braking causes the battery charge to reach the software-limited headroom the MINI just stops all regeneration and lets the brake discs do all the braking. Does the brake-pedal feel change suddenly when the headroom threshold is reached? If my MINI Cooper SE ever gets here, I'll have a chance to find out.
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Don't mean to steal the thread, but my Kona Electric is very generous with regen ( well over 40 kW) even at 100% charge, which I did a couple of days ago after top end balancing finally for the first time with 16 months ownership. (long overdue) :oops:
A good sign of degradation (without running a third party app) is an indication of that regen availability not being equivalent as when the vehicle was new as the top end is used up.
Hopefully the MINI Cooper SE has a function in the displays that indicate the amount of regen.
 
electriceddy said:
Don't mean to steal the thread, but my Kona Electric is very generous with regen ( well over 40 kW) even at 100% charge, which I did a couple of days ago after top end balancing finally for the first time with 16 months ownership. (long overdue) :oops:
A good sign of degradation (without running a third party app) is an indication of that regen availability not being equivalent as when the vehicle was new as the top end is used up.
Hopefully the MINI Cooper SE has a function in the displays that indicate the amount of regen.
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The mechanical needle in the Performance Display gauge at the left side of the SE's instrument cluster goes up to display the amount of power being used and down to indicate the amount of regenerated power going back to the battery.

Where does the Kona Electric put the regen power after the battery is fully charged? If the battery is truly 100% charged, then it cannot accept additional power. Is there a giant resistor somewhere that's glowing red by the time you get down the mountain? Our Honda Clarity Plug-In Hybrid does a strange thing: it starts the internal-combustion engine to use up excess regen power after the battery becomes fully charged. So it's actually burning gasoline (proof: the manifold gets hot) to use up the electricity it is generating! No one on the InsideEVs Clarity forum has explained how this works to my satisfaction.
 
insightman said:
Where does the Kona Electric put the regen power after the battery is fully charged? If the battery is truly 100% charged, then it cannot accept additional power. Is there a giant resistor somewhere that's glowing red by the time you get down the mountain?
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It is a crime that electric cars don't have a roof-mounted "fuel dump" Tesla coil to crackle and pop away excess regen tons.
 
insightman said:
The mechanical needle in the Performance Display gauge at the left side of the SE's instrument cluster goes up to display the amount of power being used and down to indicate the amount of regenerated power going back to the battery.

Where does the Kona Electric put the regen power after the battery is fully charged? If the battery is truly 100% charged, then it cannot accept additional power. Is there a giant resistor somewhere that's glowing red by the time you get down the mountain? Our Honda Clarity Plug-In Hybrid does a strange thing: it starts the internal-combustion engine to use up excess regen power after the battery becomes fully charged. So it's actually burning gasoline (proof: the manifold gets hot) to use up the electricity it is generating! No one on the InsideEVs Clarity forum has explained how this works to my satisfaction.
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The "indicated SOC" on the KONA EV display is only about 96% of the actual "BMS SOC" leaving a few kWh of top end buffer. I probably should have stated "indicated", thanks for the correction however its too late to change it now.:(
 
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On a related topic——is there a way to see a digital battery charge percentage in the display? Would like to see more precision than +/- 12.5% (in the eight “bars”).
 
Alf_W said:
On a related topic——is there a way to see a digital battery charge percentage in the display? Would like to see more precision than +/- 12.5% (in the eight “bars”).
Click to expand...

Yes. Press the button on the end of the left steering wheel stalk. It will cycle through the batt % as well as a other data points.


Sent from my iPhone using Inside EVs
 
insightman said:
The mechanical needle in the Performance Display gauge at the left side of the SE's instrument cluster goes up to display the amount of power being used and down to indicate the amount of regenerated power going back to the battery.

Where does the Kona Electric put the regen power after the battery is fully charged? If the battery is truly 100% charged, then it cannot accept additional power. Is there a giant resistor somewhere that's glowing red by the time you get down the mountain? Our Honda Clarity Plug-In Hybrid does a strange thing: it starts the internal-combustion engine to use up excess regen power after the battery becomes fully charged. So it's actually burning gasoline (proof: the manifold gets hot) to use up the electricity it is generating! No one on the InsideEVs Clarity forum has explained how this works to my satisfaction.
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I can't speak to the Kona, but my Bolt will simply stop regenning. As in, the car will coast instead of slowing down. It doesn't happen to me often (I usually charge to 90%, so there is still plenty of headroom for regen). But when it does happen, it is unnerving.

I had a 2010 Insight (second gen) which did what you describe. It's an odd decision for Honda to make and always drove me crazy. So you're telling me that because my battery is fully charged, I now have to burn gas?!?
 
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