Bosch battery not charging to 100%

[tallpaul]

On my Bosch Performance Class 3 Haibike I notice now that after charging the percentage indicator on the Nyon controller indicate only 95% (occasionally 98% or even 100%). Previously it always charged to 100%. I can plug the charger back in and it will go to 100%.
Perhaps there is a fault with either the charger or the battery? Any ideas appreciated. On my rides I like to have full capacity to go as far as possible.

 

[tallpaul]

Purchased a new Bosch 500w battery recently and it seems when I charge it I get the same less then 100% charge indication (on my Nyon controller). Usually around 96-97%.
I thought on my old battery that was an indication of usage over the last two years, but this new battery shows the same thing.
Could this be a malfunction of my Bosch charger?
Anyone else experiencing this? Any input appreciated!

 

[J.R.]

Sorry, I can't comment on Bosch systems. This ongoing, unanswered issue I figured I'd throw in a comment about my experience. I have three 417 watt hour BH battery packs, and every once in awhile I'll throw in a fully charged battery and the display would read 95% or 98%. When I had just one battery and it happened I thought, as you did, it was showing the pack had degraded. Then I'd charge again and it was back to 100%. Another oddity is occasionally I'd see a pack drop a few percentage points very quickly into a ride, but never saw any real drop in range.

Three plus years and three packs it's only happened a handful of times. The oldest pack, 3 years old, gets less range, which is understandable, but only 10 miles or so. I can still get 40-45 from it and 50-60+ miles from the newer packs.

It's bothered me when it's happened, but hasn't caused any problems. A gremlin I have to live with I guess. I hope you find an answer.

 

[MarkF]

There are loses in the wiring between the battery, esc and controller. Your display is not a high tech electronics monitor ether. Also is your battery cold? A battery will read lower when it's cold too. I would say 96% is within tolerances between all the factors going on.

 

[tallpaul]

There are loses in the wiring between the battery, esc and controller. Your display is not a high tech electronics monitor ether. Also is your battery cold? A battery will read

I can live with that. Being in SoCal I don't think temperature has much to do with it.

Thank you for your replies!

 

[MarkF]

I lived in Orange County for 55 years and moved to Las Vegas 3 years ago. I miss living there. Anything below 70F is cold to a battery and gets worse as you go down.

 

[Nothgiel]

I have the same thing happening to my Bosch Performance line CX with dual Batteries. On the Bosch Nyon display it will charge to 95% overnight when I plug it in again it charges to 100%.
Once it charged to 100% so I left it plugged in overnight and in the morning it was at 96%.
I noticed sometime it doesn't stop charging and the lights don't go out as they should.
Any Ideas would be welcome, no one seems to have come up with a solution.
I have tried reseting the batteries, to no avail.
Nothing to do with temperature because I have another bike with the same batteries and it charges to 100% every time.
Nothing to do with the charger, I swapped that to a different one.

 

[tallpaul]

Was surprised to see this thread active again.
I never found an answer to this, and the issue continues.
Nothgiel, I was considering swapping out my charger but you wrote that it made no difference so i won't go to the trouble of finding a new charger.
I guess I'll just have to live with it unless anyone has an idea about what is happenning.

 

[JRA]

Instead of relying on a % check the batteries with a digital voltmeter and see how close to 42v it is as soon as the charger goes green.

 

[tallpaul]

JRA, good idea, but I am concerned as to which two terminals to connect to. Don't want to be shorting out the battery!

 

[JRA]

The circuitry of the multi meter will insulate that from occurring as long as the pins don’t touch while in contact with the battery. Using the correct DC setting you will only get a reading from the positive and negative ports. If the reading has a - it only means the leads are reversed.

Usually the power ports are larger diameter than the com ports so start with them.

 

[rich c]

JRA, good idea, but I am concerned as to which two terminals to connect to. Don't want to be shorting out the battery!

Pretty sure there is a small + and - cast in the plastic. Can’t remember if it’s on the battery, or the base.

 

[lerxst]

I tried measuring voltage on one of my Bosch batteries and was unable to get a reading. I don’t think it leaves the battery connected to the terminals permanently - the controller & motor communicate with the battery to tell it to start providing power. Unless you can send that same signal to the battery while you’re measuring its voltage, you’re not going to get a reading.

 

[elainehillrider]

As I know batteries with Smart BMS try not to fully charge. It is to reduce stress in the cell chemistry. I am not sure if Bosch intends to do that. But also having 100% fully charged battery isn't that good for your battery life. 99% seems to give a longer use of your battery.