New KIOX display and Fast charger for 2019

The fast charger is certainly an improvement for some. Guess it is most useful for those having only a single battery since they are most likely to run out of juice. Having the dual battery setup I personally don't mind charging them overnight, if it takes 9 hours then let it be, there is no advantage of charging faster. But generally speaking, the faster the better. It would be of no disadvantage if they could magically be recharged in 1 minute.

Wonder if and how faster charging affects battery life?
 
tompat said:
Wonder if and how faster charging affects battery life?
Click to expand...

Fast charging is not an issue. Or else Tesla wouldn't spend billion$$ building supercharger network.
What really matters is the time spent at high voltage and high temperatures.

In fact, running a Bosch E-bike in Sport or Turbo setting strains the battery far more than fast charging.
 
How does this new display fit in the product line in respect to the Nyon and Cobi (which may be discontinued?) displays?

Faster charging never hurts.
 
Ravi Kempaiah said:
Fast charging is not an issue. Or else Tesla wouldn't spend billion$$ building supercharger network.
What really matters is the time spent at high voltage and high temperatures.

In fact, running a Bosch E-bike in Sport or Turbo setting strains the battery far more than fast charging.
Click to expand...

Interesting. I've been doing most of my Bosch charging with the 2 amp charger rather than the 4 amp as I was under the impression it was easier on the battery.
 
Over50 said:
Interesting. I've been doing most of my Bosch charging with the 2 amp charger rather than the 4 amp as I was under the impression it was easier on the battery.
Click to expand...

There are multiple scientific articles going into the depth of this. Yes, there is a very slight advantage to charging at 2A vs 4A and that is, slow charging induces less heat compared to fast chargers, but it is often shrouded by a myriad of other factors that trump this advantage. For example, if you left the 2A charger connected overnight such that the battery stayed at 100% for over 5 hours, then all the benefit of slow charging is lost. Why keeping at 100% is bad? well, lot more parasitic reactions happen at high voltages that force the chemistry to weaken considerably.

Imagine this, think of the battery as a ball room... As it begins to fill up, if you have new guests run in too fast (high voltage) or send in too many at the same time (high current), people (Li ions) start to get stressed out and someone is going to lose it and start tossing tables and chairs. Eventually, the mess is going to get to the point where the hall just can't hold as many revelers as it once did. All these Li ions going crazy at that high voltage is what can be termed as parasitic reactions at anode and cathode.

https://www.pcworld.com/article/268...last-slow-charging-may-not-be-the-answer.html

Fast charging in cars happen with 450A current or more and it is orders of magnitude more than normal charging and the currents are HUGE.
From that context, neither 2A or 4A can be called fast charging.

The most important aspect of the fast charging is how the charger handles the last 20% and you will see it is often longer than the first 70 or 80%. It is apparent from the graph.

I charge my Haibike at 4A all the time but don't go over 90% and my 400whr powerpack still holds 28miles of range (20mph avg speed) which is quite close what it was providing when brand new and this is after 6000 miles of use.

I am writing an article for Electric Bike Action magazine about the E-bike batteries and best use practices. I will link it once it is published.
 
Fast charging would be nice and would open up some different travel opportunities that at this point would feel rather contrived. With the 4A Bosch charger I find it is pretty close to one hour of charging for every hour of bicycle travel in hilly country and Tour mode (my average speed is around 12-13 mph). Cutting that in half would make it much more feasible to partially recharge during the day.

The Bosch dual-battery system makes it a pain to just charge to 80 percent since it apparently completely charges one battery before starting on the next. I'd gladly pay extra (if anyone at Bosch is listening) for an "eco-charger" which would only charge the batteries to 80 percent, especially for day-to-day use when not on journey.
 
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Ravi Kempaiah said:
I charge my Haibike at 4A all the time but don't go over 90%
Click to expand...

Hi Ravi,
So to do this, do you just use a standard charger on a timer?
Also - do you happen to know how the cell balancing is implemented on the bosch (or yamaha) battery packs, and would charging to 90% give any issues? (or does a full charge every now and again sort that out?)
 
Mr. Coffee said:
The Bosch dual-battery system makes it a pain to just charge to 80 percent since it apparently completely charges one battery before starting on the next. I'd gladly pay extra (if anyone at Bosch is listening) for an "eco-charger" which would only charge the batteries to 80 percent, especially for day-to-day use when not on journey.
Click to expand...

Are you 100% sure that it charges the batteries in order, first one to 100% and only then begins on the second one? This is not what I've heard from other sources and would be inconsistent with the usage behaviour, where it draws 5% from one battery before switching over to the other one.

I did some measurements of the charging process of a dual battery bike, it didn't begin from fully depleted batteries, I guess it was about 30-40% remaining (I have the Intuvia, so no exact readings are possible).

You can see, beginning at around 19.00, it slowly ramps up the charging current (measured in watts here, in a 230 V system) to reach its maximum of 193 W around 22.40 when it suddenly drops to 156 W and then quickly drops to 0 W.

Since there is only one curve ramping up and falling down, not two identical following each other, it also indicates it charges both at the same time (or, 5% into the first, and then 5% into the second, and so on) rather than charging the first to 100%.


I am convinced the last plateau of ~ 150 W is the "last 5-10%" trickle charging which we would like to avoid for most of the time. I plan automating this on my home automation platform, so when the charging current drops to that plateau the charger will be switched off.

About once every other hour it seems to momentarily top up the batteries for minute or two.

1531897934225.png
 
I based my observations not on power draw, but watching the blinking lights on the batteries as they charge. One battery blinks for a while (typically 2-3 hours if I am at 40% or so charge) then goes dark, and the other battery starts up blinking.

It is certainly possible I am mistaken or am misinterpreting the displays. It is also possible that the batteries only blink up to approximately an 80% or so charge. This was with an R&M Charger GX with a Bosch Performance CX drive using the charger plug on the bike.
 
As I recall it's possible to see on the Intuvia display which one of the batteries are receiving charge for the moment. What display do you have @Mr. Coffee ?
 
gljoe said:
Hi Ravi,
So to do this, do you just use a standard charger on a timer?
Also - do you happen to know how the cell balancing is implemented on the bosch (or yamaha) battery packs, and would charging to 90% give any issues? (or does a full charge every now and again sort that out?)
Click to expand...

Great question!

Bosch's BMS balances the cell even below 100%. But exactly at what point it does, I am not quite sure. BMS's have improved quite a bit and Bosch uses a good one. It doesn't need to reach 100% for it to balance.

How I do it?

Once the charge indicator on the intuvia display reaches the 5th bar, 10-15 minutes into that 5th bar flashing, I remove the charger.
On certain occasions, I charge the battery fully (let's say, once a week) but I won't keep it like that (100% charge) for hours.

The charging happens in two stages constant current (CC) (upto 80-90%) where all the Li-ions are being shuttled back to the anode and then the charger switches to the constant voltage mode for the last 10% but it does it in a slow ramp down way. The reason being: Imagine this.. you were driving a huge train. You can't bring it to a stop just like that.. the stopping distance is anywhere near couple of miles. Similarly, all these millions of Li-ions were shuttled back and you can't stop that train just like that... ideally, you want to keep the voltage and bring down the charging current and this stage (the last 10%) is called the constant voltage (CV).

@tompat The charger can only charge one battery at a time in the dual battery configuration. It's not ideal to charge the battery in 5 minute slots. I don't have the dual battery configuration but I have read that it charges one battery at a time.
 
@tompat

The Intuvia display indicates that only one battery at a time is being charged.
 
Yes I know it charges one battery at a time.

My assumption it charges them in 5% (not minute) intervals.

Why I assume this?

1. The discharge cycle is done in 5% intervals. If the system would charge the first battery to 100% before even beginning with the second battery, it would lead to one of the batteres being cycled way more often depending on your charge/discharge pattern, if you're not always doing full charges.

2. If you interrupt a dual battery charging process they both have about equal charge level. Let's say you begin charging at 30% charge level (combined) and interrupt it at 80% (combined). Check the display. Both batteries are at about 80% (individual), not the first being at 100% and the second at 50%.
 
Last edited:
Ravi Kempaiah said:
Great question!

Bosch's BMS balances the cell even below 100%. But exactly at what point it does, I am not quite sure. BMS's have improved quite a bit and Bosch uses a good one. It doesn't need to reach 100% for it to balance.
Click to expand...

Ok, thanks for that info. It would be great to know exactly how Bosch do it, but I imagine they're keeping that to themselves :)

It seems that people are getting more educated about the science behind batteries and what you should do to prolong their life (and with people like yourself doing research work directly in this area, no doubt things will keep progressing!) but it often seems difficult to work out exactly what the best practice is, especially when one doesn't have intimate knowledge of the way the manufacturers implement their designs. Its often a worry that one can do something that's actually causing more harm than good!
Cheers
 
I’m waiting for my dual battery supercharger to be delivered, so I don’t have first hand experience. But I checked out the Bosch manual from R&M homepage section downloads. It says it will alternate between the two batteries several times when charging.
 
The batteries are charged 1 battery at a time for dual battery up to 80-90% then the batteries are charged in parallel. This is what is in the MY19 user manuals. Below is the excerpt.

F45DE11F-6FB5-4872-9687-4EF4D1A23422.png
 
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