Display behaving strangely - Kalkhoff Sahel C8 Pro Disc 2011

[MGR1]

Hi all.

I had a post recently about my battery (18Ah) discharging when the bike was standing for a week or so. The battery indicators both in the display (LCD) and on the battery (LED) would jump from say 5 to 2, in one week without use. This happened three times in a period of one month, and then the problem stopped. Recharging the battery after those incidents was a bit strange, as the charge went normal until 2-3 LED's where reached, and then it finished with full charge and all LEDs went black.

About the same time I noticed another problem that took some time to reproduce accurately. When I use the backlight in the LCD display, and the charge indicators show 1 or 2 both on the battery and in the display, the assistance will suddenly cut out after some minutes riding with High assistance. The charge indicators in the display (LCD) then show no charge (no bars), however the battery LEDs (when button is pushed) show the same charge as they did before the incident.

When I turn the display off/on, the charge indicators in the display again indicate correctly (1-2 bars), and power is restored. If I keep the backlight off, the error does not occur. When I turn on the backlight in the LCD display again, it cuts out with "no assistance" within minutes. With charge indicating 3 or above, the problem does not seem to occur, even when the LCD backlight is on.

This error seems to occurs faster if battery is cold (outside temperature, 5-15 deg. C) than at room temperature (20-25 deg. C).

Kalkhoff in Germany sent me a new LCD module complete with wiring, but the problem persists with the new one. Now they say that it may be the engine itself, and that the bike will have to go to a dealer or to the factory. Since both are a long way from here, that would cost me a fortune, so I am reluctant to send in the bike.

I wonder could it be the battery? Any help on this would be greatly appreciated. Could someone with a similar bike test under the same circumstances perhaps?

I must add that the bike now has a total of 1407 km, and looks like new. It has never been ridden in the wet. Battery has been charged on a weekly basis, when LEDs are down to one. I use only the original charger. Bike is stored indoors all the time.

Regards,
Michael

 

[tillson]

Your only option may be to send the bike to one of Kalkhoff's agents. It will be reasonable for you to expect reimbursement of any costs incurred sending the bike back. Although my Kalkhoff is older than yours, I believe that the handlebar display is driven from circuit boards within the motor housing. These aren't user serviceable and will need to be investigated by Kalkhoff.

Is it possible for you to borrow another battery to eliminate it as the cause of the problem?

 

[MGR1]

I am also thinking that it would be better to test with another battery first before I conlude with anything. I will contact the dealer and ask if they could possibly send me one, although I doubt they will. I bought the bike privately and had had nothing to do with them previously.

Shipping the whole bike to the dealer and back would cost approx 3000 NOK (roughly 300 GBP), and I would risk damage.

 

[Deleted member 4366]

Your symptoms seem to point to a dodgy battery or bad connection from/in the battery somewhere. Check the easy things first like the main battery connections making good contact and the fuses nice and tight; however, the unusual charging, to me, says something inside the battery is not right like a low cell or balance wire broken off. If the battery's under warranty, take it back, otherwise you'll have to open it up to measure the cell voltages.It might be worth checking the viltage after charging to make sure the charger's working properly.

The cutting out is most likely because you've reached low voltage cutoff because one cell has reached minimum voltage, intermittent broken contact or whole battery is low and suffering voltage sag when your bike is under power.

 

[tillson]

I bought the bike privately and had had nothing to do with them previously.

Shipping the whole bike to the dealer and back would cost approx 3000 NOK (roughly 300 GBP), and I would risk damage.

Sorry, for some reason I thought that you had purchased it new from a dealer and that it was under warranty. Obviously, you may not recover the cost of sending the bike back or any repair work, depending on the circumstances. It's definitely worth trying another battery before going to the expense of sending the bike back at this stage.

 

[rog_london]

I am also thinking that it would be better to test with another battery first before I conlude with anything. I will contact the dealer and ask if they could possibly send me one, although I doubt they will. I bought the bike privately and had had nothing to do with them previously.

Shipping the whole bike to the dealer and back would cost approx 3000 NOK (roughly 300 GBP), and I would risk damage.

I'd say almost certainly a duff connection. There's a digital (data) circuit which goes from the battery to the motor and from there to the handlebar display. The fact that your problem is affected by whether the display back light is on or not tends to make this seem even more likely, as then the display draws some current to provide that light, and much less when the light is off. A faulty return circuit would corrupt the data, especially when more current is flowing.

First and most likely will be the prongs and their sockets where the battery slots into the cradle. As with car battery terminals, these can oxidize over time, and you may get a bad connection even though you never use it in the rain.

A smear of Vaseline (petroleum jelly) on the prongs would be a good idea, after carefully wiping them clean. Don't be tempted to use WD40 as that tends to get into places where it can do more harm than good, and it dries out after a while.

If that doesn't do the trick, you'll have to delve a little deeper and locate the connectors from the wiring loom to the motor assembly. Make sure these are fully pushed home. It can help to carefully unplug these and then reconnect them - the wiping action will be beneficial. However, do the easy and most likely bit first - the battery connectors.

Rog.

 

[flecc]

Another possibility is the base contacts for the battery have some burn marks. See this link on my Panasonic support website for the details. One of the contacts is for the display metering information.

If that's the case, a replacement contact base plate is readily obtainable and easily fitted.