Rise Battery losing charge over a few days? Fault? normal? age?

[b33k34]

We've had our 2 Rises since May 2021. They get used at least once every week and mine has now done 3000km+

The last couple of times we've been out I've charged them early in the week (Monday/Tuesday), removing the charger within a few hours of the light going to flashing green. Starting up the bikes on Saturday one was reading 92%, one 93% (we're using Garmin 130's so have accurate %age).

I've a feeling they've always done this. Most of the time we've had them I've had the chargers on a timer so I'd give them four hours charge after a ride, and give them a top up the night before we go out (30 minutes or an hour). The batteries definitely will still hold full 100% doing that.

It seems pretty poor that a Li-ion battery would lose that much charge whilst sitting at room temperature for a few days - and I'd wondered if the issue was leaving the chargers connected (but switched off at the mains by the time plug) but the last few weeks of 'manually' charging proves that isn't the case.

Is anyone else seeing the same?

 

[aarfeldt]

Does the Garmon Edge 130 ever show 100 % ?

 

[b33k34]

Does the Garmon Edge 130 ever show 100 % ?

Yes, if I charge it the night before it's 100%. If I leave it fully charged and wait a few days it seems to be dropping by nearly 10% of charge.

 

[aarfeldt]

My M10 is also from mid 2021, and it's about 4.000 km.
I charge it fully, and 2-3 days later I ride it....and it has then fallen to 99%.

Temperatur is around 5-10 degree at the moment....what is yours ?
My bike is inside a workshop..... not heated though.

 

[b33k34]

My M10 is also from mid 2021, and it's about 4.000 km.
I charge it fully, and 2-3 days later I ride it....and it has then fallen to 99%.

Temperatur is around 5-10 degree at the moment....what is yours ?
My bike is inside a workshop..... not heated though.

Bike lives indoors, constant 20C

 

[aarfeldt]

Bike lives indoors, constant 20C

So when you after 3 days makes the batteri readout at 93%....is it still at the same temperature, og lower at the track ?

 

[b33k34]

So when you after 3 days makes the batteri readout at 93%....is it still at the same temperature, og lower at the track ?

Clearly not - charged at c20C at home, but outdoor temp was still around 10C the last few weekends. I could understand if this was at near freezing temps.

 

[Mikerb]

Measuring the state of charge of a lithium battery is most likely done on our bikes merely by measuring voltage.............if so it is not particularly accurate to start with!! Voltage drop as a percentage of the rated voltage of the battery is very small until battery is more that 70% discharged....and there can be losses between the battery and the system monitoring its voltage.

Leaving a disconnected charger connected to the charging port could well result in some voltage leak, so not a good idea.

On my ( Bosch Smart System) bike the Kiox reads 100% well before the charger auto switches off............and the battery is clearly not 100% charged in terms of how quickly the first of 5 LEDS shows 5% discharge when I start riding, compared to if I let the charger continue until it switches off. This suggests to me that the method the charger uses to determine full charge is not the same as the system the bike uses when in use, the latter being less accurate.

 

[Gardcol]

I have a Feb21 M10 with 7,000km on it and battery will hold to 99% for a week after charging.

 

[shredjim]

I've had my M10 for one month longer than you and have similar total miles ridden. I ride steep single track in PNW with lots of extended climbing and challenge my battery capacity often. From the beginning, if I don't top up the night before or day of ride I end up with less battery capacity than desired. Even when the Shimano display or connected phone shows full capacity ie 5 bars, the capacity goes away considerably faster when no top up. This is all with single battery. With the extender rarely a capacity issue.

 

[MAster]

We've had our 2 Rises since May 2021. They get used at least once every week and mine has now done 3000km+

The last couple of times we've been out I've charged them early in the week (Monday/Tuesday), removing the charger within a few hours of the light going to flashing green. Starting up the bikes on Saturday one was reading 92%, one 93% (we're using Garmin 130's so have accurate %age).

I've a feeling they've always done this. Most of the time we've had them I've had the chargers on a timer so I'd give them four hours charge after a ride, and give them a top up the night before we go out (30 minutes or an hour). The batteries definitely will still hold full 100% doing that.

It seems pretty poor that a Li-ion battery would lose that much charge whilst sitting at room temperature for a few days - and I'd wondered if the issue was leaving the chargers connected (but switched off at the mains by the time plug) but the last few weeks of 'manually' charging proves that isn't the case.

Is anyone else seeing the same?

I thought about your issue. I can imagine that the battery management system ist trying to balancing your battery I.e. a particular cell does have to much voltage difference in comparison to the others. Since the cheapest method for balancing is to have a passive balancing, which causes energy loss. So the weakest cell pulls down the rest…, like in any company

Sad but probably the reason

Cheers

 

[cookie70]

interesting, I've had mine about 10 months with 2800km on it, never looked that closely at charge percentages just charge it and then ride when I can. Is there an app to see how many cycles the battery has done?

I came from the RC world where the chargers have balancing ports etc so I had wondered how these EB batteries work. I assumed the simple charge we have for the rise doesnt do any balancing at all.

 

[MAster]

interesting, I've had mine about 10 months with 2800km on it, never looked that closely at charge percentages just charge it and then ride when I can. Is there an app to see how many cycles the battery has done?

I came from the RC world where the chargers have balancing ports etc so I had wondered how these EB batteries work. I assumed the simple charge we have for the rise doesnt do any balancing at all.

I come from e-car development and there it is often integrated into the battery management system(BMS). It wakes up every now and then and checks the cell voltages, if they exceed the boundaries it starts to balance. This is done via a resistor, which dissipates the energy. Moreover, the BMS consumes energy all the time for this monitoring.

But I do could not find any information on the SIMPLO BMS online.

 

[Mikerb]

I dont know why the Rise battery s hould be any different to other bikes. The standard practise is for cell balancing to be the final stage during charging. Since no power is supplied to the battery unless it is being charged or until the bikes controller switching that current on when the battery is in the bike, I do not see how the BMS can be active without any power source for its processor.

 

[MAster]

I dont know why the Rise battery s hould be any different to other bikes. The standard practise is for cell balancing to be the final stage during charging. Since no power is supplied to the battery unless it is being charged or until the bikes controller switching that current on when the battery is in the bike, I do not see how the BMS can be active without any power source for its processor.

What I found out is that the standard e-bike charger use a CC/CV procedure. How should here it be possible to balance certain cells? For determining cell miss balance it would be necessary to measure the OCV of the cells without current flow. Wake up during hibernation should not be a technical problem for a bms that’s hard wired to a battery.
If this is not implemented in e-bike BMS probably it would be necessary to keep the charger connected for at least a couple of hours, when the battery is fully charged. But this is just a guess.

Cheers

 

[mike_kelly]

Many BMS system will put the battery in storage mode after a few days of lack of use. A Lithium battery does not store optimally at full charge. It should be somewhere around 65%. So many smart systems will automagically bring the voltage down to storage level if the battery is not used for a specified period.

 

[Mikerb]

What I found out is that the standard e-bike charger use a CC/CV procedure. How should here it be possible to balance certain cells? For determining cell miss balance it would be necessary to measure the OCV of the cells without current flow. Wake up during hibernation should not be a technical problem for a bms that’s hard wired to a battery.
If this is not implemented in e-bike BMS probably it would be necessary to keep the charger connected for at least a couple of hours, when the battery is fully charged. But this is just a guess.

Cheers

...which is precisely what happens. When charging my Bosch battery ( Smart system with a Kiox Fitted) the charger does not switch off even when the Kiox says the battery is 100% charged. It can continue for another hour before switching off.

 

[Mikerb]

Many BMS system will put the battery in storage mode after a few days of lack of use. A Lithium battery does not store optimally at full charge. It should be somewhere around 65%. So many smart systems will automagically bring the voltage down to storage level if the battery is not used for a specified period.

well not on any EMTB battery I have used...indeed it is why you are a dvised not to charge to 100% unless the bike is a bout to be used in the next day or so. The only time I have had the battery standing 100% charged for any time was when loading it in the van to go on holiday. Probably not used for 2 days......battery still at 100%.