Bosch Battery Full?

[ottomark]

My question has to do with the Bosch battery. I have a Supercharger, so two batteries. I've had the bike for two weeks and put about 200 miles on it. My first day, the batteries were plugged in overnight, and when I went to ride, they showed 97% full. Earlier this week, after a night of charging, they showed 94% full. This morning, they showed 92% full. My question is what your batteries show after a complete charge. 100%? Less?

 

[Afren]

I too bought a Supercharger a few weeks back and I had the same experience as you concerning the batteries. When I charge the batteries in situ, the best I can hope for is 96% even if I leave it to charge for over 24 hours, however, when I took the batteries out of the bike and charged one with a normal Bosch charger as opposed to the rapid 6A charger you get with the Supercharger I got 100% charge so I can confidently tell you that the issue is not with the batteries or the charger (as I returned the original 6A charger and exchanged it with another new one but the same result) but rather the way the 6A chargers charge two batteries at the same time if that makes sense. I think if you were to charge each battery individually you might get a different result even if you were to use the 6A charger. I hope it makes sense.

 

[ottomark]

That's very helpful, Afren. Thank you. I'll try charging them directly.

 

[CampGareth]

Huh, I wonder if this is to do with the range/lifespan tradeoff from charging a battery to a higher voltage. Charge it to 100% and you get 500 cycles, charge it to 95% and you get 800 cycles, that sort of thing. Obviously if you charge to 100% you can go a few miles further on a single charge but with two batteries you probably don't need those few miles.

If so, bravo to bosch. If not, ah well, it's a somewhat useful bug.

 

[steve mercier]

How do you two like your Superchargers so far?

 

[ottomark]

First, I'm learning that the charging varies dramatically. Today it charged at one point to 98% and and later saw it at 94%. I assume this has something to do with charging the two batteries at once. But the fact that I could get it to 98% is encouraging.

With respect to the bike itself, I love it and think it was the right choice for me. This was my first week being able to commute every day -- and I commuted 150 miles. So it was a good test of the bike. I rode in nearly 100 degree weather as well as a torrential downpour. In both instances, the bike handled well. I noticed that the day after the rain, the Gates drive belt (I have the GT Vario HS) was a little squeaky at first but settled in. I haven't adjusted anything from the way the bike came except the elastomer on the Thudbuster, and right now I have no intention of changing anything except perhaps the pedals at some point, but they don't bother me.

My one complaint is with the Kiox display. The display itself is fine, but I can't do a lot of what I thought I could. For example, it's supposed to track your rides and download each. I have not been able to do that (removing the display, waiting for it to turn off, etc.). That's a bummer. Second, there's room for a heart rate monitor but I currently don't see a way to connect another device to the Kiox other than my phone. These are issues others have complained about...

 

[Alaskan]

I get the same results...some number between 94% and 98% while charging with batteries on the bike both my Homage and my Delite...this using a standard 4 amp charger. The issue is neither the bike nor the charger but rather something in the Bosch battery management system.

 

[Afren]

For the very first time in almost a month I got 100% charge even though I charged the two at the same time on the bike using the Rapid 6A Bosch charger that came with the bike. However, when I turned off the Kiox and turned it back on again, it showed 99% charged. Weired or what? I believe the problem is with the chargers' BMS. I call it a “problem" but this might be deliberate and have a good reason/explanation behind it. So it's back to reading the manual I'm afraid. I don't know about the rest of the contributors here but I rarely read instructions and manuals that come with the products I buy. I wonder if that's a man thing or a me thing?

 

[lerxst]

I did read the manuals and they said nothing about this 95%-99% thing. That said, coming from the world of consumer electronics, it is obvious to me that this behavior is intentional and is part of an effort to extend usable lifetime for the battery packs. Most consumer electronics significantly slow down charging when the battery gets to 95%. However, most also do eventually get to 100%, unlike Bosch. So my conclusion is that Bosch is seeking to improve usable battery lifetime, but did a kind of poor job of implementing the feature, and an extremely, borderline negligent job at communicating this “feature” to its customers.

 

[Ravi Kempaiah]

So my conclusion is that Bosch is seeking to improve usable battery lifetime, but did a kind of poor job of implementing the feature, and an extremely, borderline negligent job at communicating this “feature” to its customers.

The reason why Bosch display show 95% when in dual battery configuration could because it charges each battery in increments of 5%.
After one of the packs reach 100%, the other is still at 95% but the charger cuts the power because one of them has reached full capacity.

This doesn't happen when you charge each pack separately. So, if you take two packs outside and charge them individually, both will be charged to 100%.

 

[lerxst]

This 95% charge thing happens on my single battery Trek Powerfly Speed the exact same way it happens to my dual battery R&M Delite. It’s got nothing to do with dual battery charging or not. Happens exactly the same way whether batteries are charging on the bike or off bike, too.

 

[Ravi Kempaiah]

This 95% charge thing happens on my single battery Trek Powerfly Speed the exact same way it happens to my dual battery R&M Delite.

Trek Powerfly Speed has the Purion display and it doesn't show battery %, it only shows 5 bars. Have you switched them to Nyon?
How do you even read % on your Delite? because it has the Nyon?

The Bosch charger is designed to charge the batteries fully to 100%, not 95%. Only the Delite I have had this happen whereas my BULLS and the other Haibike I have had did not experience this.

You could try taking off the packs from your delite and charging them seperately off the bike, you will be able to charge them to 100%.

 

[lerxst]

Nope, my Powerfly Speed has a Nyon, as does my R&M.

 

[lerxst]

You didn’t read my earlier post where I said, the charging % situation is totally unchanged whether charging on bike or off bike. My batteries charge up to 95% whether on bike or off. Sometimes I see 96%. Think I saw 97% once. But most of the time, 95%. I am not surprised that your non-Bosch bike’s aren’t doing this.

 

[Ravi Kempaiah]

Sometimes I see 96%. Think I saw 97% once.

Perhaps the Nyon is not calibrated to read the voltage well. What Nyon considers as full voltage, nobody knows.
There is consistent discrepancy in Bosch's equipment example: Intuvia/Purion reads higher speed than the actual GPS. This is a well-known issue documented in several Bosch forums.

There are several batteries that show % instead of 5 bars that people see on Bosch bikes. FYI: Both Haibike and Bulls have the same Bosch system that you use.

 

[lerxst]

Perhaps the Nyon is not calibrated to read the voltage well. What Nyon considers as full voltage, nobody knows.

This is emphatically not true and thus, misinformation. The Nyon has no idea how to observe battery voltage. It does not have any sort of calibration that needs to be done, or even could be done. This is because the Nyon does not measure battery voltage (except for its built in battery, which is separate from this discussion). The motor is what measures the battery capacity - if you think about it, this makes sense, as only the motor has visibility into the voltage of the battery. The signaling wires that go up to the Nyon (or Intuvia, or Purion, or Kiox) controllers do not conduct the full battery voltage. They’re given a constant DC source, stepped down by the motor. So even if the Nyon wanted to measure battery voltage, it wouldn’t have access to that information.

The Nyon (and all other controllers) display of battery capacity is simply taking data given to the controller by the motor and displaying it.

In conclusion, only the motor has access to the true battery voltage, and thus only the motor is capable of calculating battery percentage. It then passes that fact (and not the source data that lead to that fact) to the controller display.

Now the motor itself probably does have some sort of calibration data to determine what battery voltage equals percentage remaining capacity, however the adjustment of that algorithm is not possible via end user, or even via a Bosch dealer. Bosch dealers might be able to trigger the motor to begin anew on its calibration, but that’s it. The algorithm takes into account data stored inside the battery itself (how many charge cycles it’s seen) along with some proprietary Bosch data.

 

[Ravi Kempaiah]

This is emphatically not true and thus, misinformation. The Nyon has no idea how to observe battery voltage. It does not have any sort of calibration that needs to be done, or even could be done. This is because the Nyon does not measure battery voltage (except for its built in battery, which is separate from this discussion). The motor is what measures the battery capacity - if you think about it, this makes sense, as only the motor has visibility into the voltage of the battery. The signaling wires that go up to the Nyon (or Intuvia, or Purion, or Kiox) controllers do not conduct the full battery voltage. They’re given a constant DC source, stepped down by the motor. So even if the Nyon wanted to measure battery voltage, it wouldn’t have access to that information.

The Nyon (and all other controllers) display of battery capacity is simply taking data given to the controller by the motor and displaying it.

In conclusion, only the motor has access to the true battery voltage, and thus only the motor is capable of calculating battery percentage. It then passes that fact (and not the source data that lead to that fact) to the controller display.

Now the motor itself probably does have some sort of calibration data to determine what battery voltage equals percentage remaining capacity, however the adjustment of that algorithm is not possible via end user, or even via a Bosch dealer. Bosch dealers might be able to trigger the motor to begin anew on its calibration, but that’s it. The algorithm takes into account data stored inside the battery itself (how many charge cycles it’s seen) along with some proprietary Bosch data.

Without knowing the upper cut-off of Bosch battery BMS attributing some smart battery management to Bosch batteries is just pure confirmation-bias and Pollyanna.

Intuvia and Purion reads higher speed than actual GPS speed measured by Garmin or Wahoo. The speed sensor on the magnet just passes the reading to the motor controller, which it then processes and sends it to the display. If the controller can accept higher than true speed, then it makes me wonder what kind of "intelligent" controller programming has been done.

Until the upper cut-off voltage of BMS is known, everything we discuss is pure speculation.

 

[lerxst]

None of this has anything to do with GPS. The factors that go into speed readouts disagreeing have nothing to do with battery capacity display. You can’t point at inaccuracies in speed and somehow attribute that to your battery theory.

 

[Ravi Kempaiah]

You can’t point at inaccuracies in speed and somehow attribute that to your battery theory.

Without knowing a simple parameter like "BMS cut-off voltage limit", you can't somehow attribute some special feature to batteries either

If Intuvia/Purion can diplay higher speed, Nyon display lower battery %, then it shows certain error/inaccuracies in output reading abilities of the interfaces used in these systems, not some esoteric German engineering.

Again, without knowing BMS cut-off limit, we can't say what is 100% and what is 95% and whether it is an inaccuracy or otherwise.

 

[lerxst]

Without knowing a simple parameter like "BMS cut-off voltage limit", you can't somehow attribute some special feature to batteries either

If Intuvia/Purion can diplay higher speed, Nyon display lower battery %, then it shows certain error/inaccuracies in output reading abilities of the interfaces used in these systems, not some esoteric German engineering.

Again, without knowing BMS cut-off limit, we can't say what is 100% and what is 95% and whether it is an inaccuracy or otherwise.

I address your misinformation below:

1. I have run the Purion, Intuvia, and Nyon controllers on my Trek, and both the Intuvia and Nyon controllers on my R&M. They all display the exact same battery and speed readouts, to the best of the display’s ability (i.e., just battery bars on the Purion and Intuvia.) That’s because they don’t calculate those values, they simply display what the motor tells them to display. That you keep attributing different speed/battery behavior to different controllers demonstrates you are reasoning about the system from a position of ignorance, which is why your conclusions do not reflect reality.

2. Contrary to your repeated claims about cutoff voltage, knowing that value is not necessary for any of the determinations I’ve shared in this thread. The reasons behind speed display inconsistencies are already well known and discussed in other threads and have nothing to do with batteries, whether we know when the charger cuts out or not.

3. It literally doesn’t matter what voltage the charger cuts off at, because at the end of the day the only thing that matters is what the battery & motor thinks the capacity is. Knowing what voltage the charger cuts off at doesn’t change the fact that a motor that thinks the battery is at 95% is going to treat the battery as if it’s at 95%, even if truly (in terms of physics) the battery might be at a different percentage.