LCD3 meter battery meter not working and motor cutting out

[destructimo]

Hi All,

I've been guesting for a while but things have got beyond me now and the search function.

I've got this kit: http://www.greenbikekit.com/electric-bike-kit-1/front/36v-250w-front-hub-wheel-kit-with-36v-samsung-frame-battery-with-built-in-sine-wave-controller.html with the 15AH battery option fitted to my old aluminium frame hardtail MTB.

The install wasn't too bad. Had to modify the pedelec sensor to fit on the chainwheel and redish the front wheel so it was central in the forks, but got it all in an working perfectly.

I've done about 30 odd miles on it and have come across a problem

The battery meter (bar graph) on the LCD will go from full to empty and flashing cutting power to the motor within a few seconds of the LCD being switched on. The sub menu volt meter though shows 41V.

I've checked all the plug in connections and also set the P5 to zero so that the meter shows actual voltage and not the smoothed out version if it's set to 12 to make diagnosis easier.

Any clues as to why the battery meter will show zero when the bike battery and indeed the LCDs own voltage measuring function shows a good charge?


Thanks



Des

 

[Deleted member 4366]

It probably thinks you have a 48v battery. You need some way to run your battery down to about 36v. Disconnect the battery and reconnect it, which should make the LCD reset. It has automatic voltage detection. It's a mystery how it does it, but they don't always get it right if you install a battery at a voltage that could be either. Maybe the damping factor P5 has something to do with keeping it right once it's decided correctly.

 

[destructimo]

Thanks ever so much for the reply. That makes sense as it's the only possible cause since the battery level meter is what seems to control the output and somehow knows or doesn't the difference between a 36v and 48v battery.

Strangely it was doing this intermittently once the battery was down to 38 volts yesterday before I charged it up which would be below the 40v LVC for a 48v battery.

 

[Deleted member 4366]

The LVC can be as low as 38v, regardless of what's written on any controller. This is the LCD anyway, which would probably have a lower limit than the controller.

 

[destructimo]

Just sorting out a discharger for the battery at the moment.

I did also try increasing the LVC on the LCD3 from it's default of 30/40V depending on battery type to 32/42V but no joy. Maybe I'll try reducing it to 28/38V.

I'll let you know how it fares with the battery at a lower voltage.

One thing that puzzles me is, does the LCD meter then retain the battery type in memory somewhere or does it just try and work it out every time the power is turned on?

 

[Deleted member 4366]

I don't know how they work in detail. They have a fairly substantiantial microprocessor inside, some flash memory and some software/firmware. They communicate with the microprocessor in the controller, passing instructions backwards and forwards.

 

[destructimo]

I managed to get the battery discharged down to just under 36V but it had recovered to 37.1V by the time I got it back on the bike, but still no joy unfortunately.

It seems that the LCD3 has got itself stuck in 48V mode or maybe it's just banjaxed as it was working perfectly even with a fully charged battery. I've e-mailed the supplier to see if they have any ideas.

 

[Deleted member 4366]

Persevere with it a bit. Someone else had a similar problem, which suddenly fixed itself. Try leaving it switched on for a bit.

 

[destructimo]

Yes I think I saw that mentioned, either here or on ES. Sadly no joy from this one though.

I'll let you know what response I get from GBK.

Quite frustrating though because when it was working properly it was indeed excellent!

 

[destructimo]

Just a quick update. I finally received a replacement meter and controller from GBK today in the post.

Plugged in the new meter, no joy, same symptoms.

Put the new controller on with the old meter...works perfectly and instantly identified the battery, even charged to 42V. Fingers crossed for smooth sailing hereon in.

Thanks for all the help and I hope this too helps another frustrated pedelecer.