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[DonTom]

My 2020 SS9- likes to stay at 91% SOC in the LPR mode.  Is this normal or a bit on the high side?


-Don-  Reno, NV

[PWM]

Not normal.

Should stop at 80% SOC but will not initiate if above this level.

[DonTom]

Not normal.

Should stop at 80% SOC but will not initiate if above this level.

80% is what I expected it should be, but it's always been high on mine, but not always 91%. Sometimes it's as low as 86% soc.


I suppose it could be that my % of SOC reads high. But it's now staying right at 91%. I have seen it recharge to bring it back up to 91% in the LPR mode and I always start the LPR mode when it's down low, such as 20% SOC. From there it will bring it up to 91% and leave it there.


-Don-  Reno, NV

[DonTom]

I wonder if temperature effects where LPR mode takes it. It's been very cold here. I just noticed it's now at 89% SOC in the LPR mode and it's not activating the charging to bring it back up to the old 91% SOC. Perhaps a little warmer today and letting it drop a bit.


It's been mostly below freezing here.


-Don-  Reno, NV

[BigPoppa]

Even when I had my SS9- LPR mode would only charge to 80% My Ribelle is currently in LPR mode but it was at 80% already when I put in LPR mode. It’s my understanding that LPR mode tries to keep the battery between 20%-80% so if you were at 91% when you put it in LPR mode, it probably won’t try to charge the battery for some time.


I believe it may still power up to balance the cells from time to time though. Like I posted in another thread, I’ve yet to catch my Ribelle charging since I’ve put it into LPR. I even turned it on once just to make sure it was in LPR. My SS9- seemed to kick on once every week or so for a bit but this Ribelle has been dead quiet every time I’ve been in the garage. It’s possible it has kicked on to charge and/or balance the cells when I haven’t been in the garage. I definitely don’t spend anywhere near as much time in the garage now that its gotten colder as I do in the late Spring to early Fall.

[DonTom]

so if you were at 91% when you put it in LPR mode, it probably won’t try to charge the battery for some time.

Nope. I always start the LPR when well below 50% SOC. Last time,  I started at 20% SOC and the LPR mode took it to 91% SOC before it stopped the charging.


-Don-  Reno, NV

[PWM]

Don't know for sure but was understanding cell balance occurs only when charging to 100% (starts north of 95% on my bike) usually a shunt regulator initiates discharge cycle for the weak cells first that fill to capacity early.  Same conditions / circuits don't exist at 80% SOC, don't think so anyway w/o being intrusive to power delivery.

[DonTom]

Don't know for sure but was understanding cell balance occurs only when charging to 100% (starts north of 95% on my bike) usually a shunt regulator initiates discharge cycle for the weak cells first that fill to capacity early.  Same conditions / circuits don't exist at 80% SOC, don't think so anyway w/o being intrusive to power delivery.

I recall reading that the LPR mode keeps the battery balanced.


I wonder if the LPR SOC% is depeandent on battery temperature. Perhaps it charges higher when extra cold. It is snowing here right now and it has been extra cold here lately.


-Don-  Reno, NV

[PWM]

Nossir - LPR does not balance cells...per '21 Eva owners manual...

 "When this function is deactivated, a longer balancing period may be required"

[DonTom]

Nossir - LPR does not balance cells...per '21 Eva owners manual...

 "When this function is deactivated, a longer balancing period may be required"

Page 96 of my 2020 Esse Essse 9 Owner's manual:

"LPR function (Long Period Rest):


LPR is a function which may be activated by the user to protect the battery against deterioration during prolonged periods with the motorcycle not in use (over 30 days). This function maintains an optimum charge level and keeps the battery cells correctly balanced. When LPR mode is active, the motorcycle wakes up periodically and runs a battery cell voltage test. If it is necessary to charge the battery or balance the cells, the motorcycle automatically activates the charging system and implements the battery maintenance cycles necessary. This ensures that the battery is kept at an optimum state of charge of 85-87%. To use LPR effectively, we recommend activating the function only at battery charge levels lower than 87%. Maintenance cycles are performed automatically and periodically until the user deactivates the LPR function."

BTW, I just now turned on the bike to get the SOC (still is in LPR). It's at 89% SOC. I assume that is close enough, but I have seen it recharge to 91% SOC.


-Don-  Reno, NV

[jotjotde]

Hi Don,

for your info, the manual of my '22 Ribelle says, during LPR the BMS keeps the battery's SOC at an optimum level of 80-90 %.

Seems, the range have been revised since '20.

[BigPoppa]

I’ve noticed a couple of differences in the manuals between the 13kw and 21kw battery packs:

• The manual for my 13kw SS9 wanted you to periodically drain the battery to 0% whereas that’s no longer required as per the 21kw Ribelle manual.
• As Don pointed out, the 13kw SS9 manual indicated the cells are balanced while in LPR whereas it’s not mentioned in the 21kw Ribelle manual.

Seems like the differences in the batteries go beyond just capacity and battery chemistry to include BMS “best practices”.

[PWM]

The assumption is 13kW and 21kW share basic BMS design.   NCM chemistry used in both.  The recommendation to drain fully was likely to force a low-side BMS function for VCU calibration which is a firmware parameter that doesn't matter today.

[DonTom]

I noticed my bike will drop to 88% SOC and then recharge back up to 91% when in LPR mode.


It could be my SOC is a little off.


Another thing I would like to ask. When I am out of LPR mode and charge to full (100% SOC )in one to two blocks, all downhill, I will be at 98% SOC. But below that 98% SOC, I can go quite a ways before getting down to 97% SOC. Do others also experience the same?


My bike is the 2020 Esse Esse 9- (smaller battery).


-Don-  Auburn, CA

[Demoni]

I'll be honest I do not have specific data regarding SOC values for LPR mode. I can share some info that might help understand the behavior of the bike.

The main feature of this mode is it allows the bike to initiate AC charging when required during storage. In normal operation (LPR off) after a AC charge session has completed a new session can not be initiated (requires a unplug of the charge cable).
Our bikes only perform cell balance at the end (between 96-98 % SOC) of a full charge. This is why it is important to fully charge a bike to 100% after storing it in LPR mode for an extended period of time.
Every time a bike is charged to a SOC below where the balancing process starts the delta between the high and low cell voltages will increase slightly. This is caused by the natural differences in cell resistances. A bike with excessively unbalanced cells can experience low voltage cutbacks when at low SOC, this is due to one or more cells reaching the safe minimum voltage before the rest of the cells in the pack. 

Another thing I would like to ask. When I am out of LPR mode and charge to full (100% SOC )in one to two blocks, all downhill, I will be at 98% SOC. But below that 98% SOC, I can go quite a ways before getting down to 97% SOC. Do others also experience the same?

-Don-  Auburn, CA

This is normal. A bike will only reach 100% SOC when the delta between high and low cell voltages in within a set value. The moment you start drawing power from the battery all the cells will see some voltage sag. As mentioned above cells with different resistances will discharge at slightly different rates. This difference can cause a slightly higher voltage imbalance. If that difference puts the delta under the "balanced" value the dash will display 98% SOC.

^Hope that makes sense.