battery problem? 2008 Pro Connect

[lowmtr]

Just after a little help please.
I just purchased a (hardly) used 2008 Kalkhoff Pro Connect which I could well believe has only done around 200 miles as described. Took it for its first outing today and very impressed. However I'm not sure if I've got battery problems or not and would appreciate some advice: The battery was fully charged and showing 3 bars on the handlebar control, for about 7 miles. As I hit the very first hill I changed down gears but almost immediately the battery meter dropped to low and started flashing and the bike gave up climbing. I could not clear what I presume is the low battery warning with a power off. A this point I took the bike home through a different route with a more gentle slope and I got battery assist for the 7 miles home but with the low power LED flashing all the way. Once home I pressed the battery button and this also indicated a single flashing LED confirming (I guess) a low battery charge. Just wondering if I have to now budget for a new battery, whether there is anything I can do here or perhaps I did something wrong in tackling the hill? I believe the bike is completely standard apart from 19 tooth rear and 12 tooth front sprocket fitted by the previous owner. Thanks for any help! Alan

 

[tillson]

The battery level meter on these bikes can drift. Try running until the battery is completely flat and the motor cuts out. Then fully recharge and see how it performs.

My 2008 PC battery is still ok @ 15000 miles 5 1/2 yrs, so there is hope for your battery.

Edit:

Have you tried the battery capacity test? Press and hold in the button on the battery. Initially it will display charge level, but if you keep it pressed in, the lights will go out momentarily and then come on again to give an indication of battery condition. 5 lights good condition and capacity > 80%, 1 light capacity < 20%. Completely discharging the battery can re-set this test. Again, it is susceptible to drift just like the charge level.

If the above fails to work, it is worth looking on eBay for a new battery. The last time I looked, some of the German shops were selling replacements much cheaper than the UK dealers.

 

[lowmtr]

Thanks for the help, after an overnight charge its showing 5 bars when pressing the battery button for over 5 seconds. I'll go for a full trip, run the battery right down and see how it goes.

 

[Deleted member 4366]

Please let us know how you get on.

 

[El Champiero]

I had a strange thing happen once to my old Bosch battery - it began to stop charging at 4 green lights instead of the usual 5. A few runs on it to completely run it down flat and then recharge sorted it out. Sometimes the BMS can certainly go a bit odd at times in batteries. You could also measure the voltage of the battery with a multimeter at full charge and then take a few voltage readings when it starts to drop. This will help give a better idea of what is going on inside. It is possible to re-cell these batteries for a very reasonable cost - if in fact some or all of the cells inside are found to be defective.

 

[lowmtr]

just an update, I'm still baffled but will work on the various bits of advice given so far:
1) took it for another run after full charge, exactly the same thing happened. Bike worked fine for about 10 miles, just showing 2 bars and assist working fine until I hit the same hill, display immediately drops to one bar flashing on the indicator (i.e. in seconds)
2) Did as before as it wasn't going to climb the pretty steep hill in question, took a 7 mile more gradual hill home, flashing low battery display on the handlebar display all the way home, but did get what felt like pretty reasonable assist.
3) When I got back the battery pack was also flashing a single LED, the measured voltage was 24.96v and holding the battery button for over 5 seconds displayed 4 bars (which I thought was a bit odd?)

I'll do some more testing and voltage measurements. A couple of thoughts...could this be some sort of torque/speed problem due to a pretty steep hill and the previous owner swapping to 19 tooth rear/12 tooth front combo?
Also just wanted to check with other owners..Am I being a bit over optimistic with the hill climbing? It is a pretty steep hill, I can just about do it without stopping on a normal bike but it would defeat many less fit cyclists. I had assumed the mid drive bikes can do this, albeit at low speed?
Thanks again for any help

 

[tillson]

just an update, I'm still baffled but will work on the various bits of advice given so far:
1) took it for another run after full charge, exactly the same thing happened. Bike worked fine for about 10 miles, just showing 2 bars and assist working fine until I hit the same hill, display immediately drops to one bar flashing on the indicator (i.e. in seconds)
2) Did as before as it wasn't going to climb the pretty steep hill in question, took a 7 mile more gradual hill home, flashing low battery display on the handlebar display all the way home, but did get what felt like pretty reasonable assist.
3) When I got back the battery pack was also flashing a single LED, the measured voltage was 24.96v and holding the battery button for over 5 seconds displayed 4 bars (which I thought was a bit odd?)

I'll do some more testing and voltage measurements. A couple of thoughts...could this be some sort of torque/speed problem due to a pretty steep hill and the previous owner swapping to 19 tooth rear/12 tooth front combo?
Also just wanted to check with other owners..Am I being a bit over optimistic with the hill climbing? It is a pretty steep hill, I can just about do it without stopping on a normal bike but it would defeat many less fit cyclists. I had assumed the mid drive bikes can do this, albeit at low speed?
Thanks again for any help

My battery (2008 Kalkhoff Pro Connect) did exactly the same thing as you describe, dropped from three LEDs to one flashing LED in a very short distance. It then went on for miles with the flashing LED and continued to provide assistance. A full discharge (until the motor cuts out and the LED flashes at 2Hz) followed by a full charge sorted it out and the battery meter became more linear. It also restored a 4 LED capacity indication back to 5. You just need to carry out this process occasionally.

 

[Gringo]

I have a 2008 Agattu and assume it has the same battery/ motor combination.
I have made some observations since buying the bike 6 years ago.

1/ I find mileage and assist levels are affected by so many different things.
On my last ride I just managed 10 miles before the battery was flashing but that was off road in some stick mud with constant assist between 1/3 & 1/1.
The week before I managed 30 road miles and still had some battery left, I was only using assist on hills I couldn't manage without it, even in 1st gear !

2/ gearing makes a vast difference. Recently Whilst changing ratios i accidentally found myself with an assisted speed well above 20 mph, it was brilliant, effortlessly passing mere mortals struggling on there ordinary cycles , until the battery faded after 8 miles. Fun while it lasted but top speed wasn't my goal so I played with my ratios some more and now have just what I need.
In conclusion, I'd say your gearing is killing your range.
For maximum range use assist only when you need it.
For maximum fun use assist any time you like.

 

[lowmtr]

thanks for the help, just thought I'd post an update:
I put the standard front and rear gears back on the bike and did a full discharge cycle. The bike is much happier and manages the steep hills around here fine and does not exhibit the straight to single battery bar issue anymore.
I'm a keen cyclist and use a normal bike everyday. However this bike is so much fun I'm finding all sorts of reasons to run errands regardless of how many hills.
thanks again to all who pitched in with their help