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Gotway MCM4 won't charge above 70%


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I recently bought a Gotway MCM4 340wh and it doesn't seem to charge above 65%-70% (~62.25V) according to the android app. Even if I leave the charger that came with it plugged in for hours, it won't raise above this.  The light on the charger stays green, so it won't charge further. Here's what the LEDs look like on the wheel when it is at "full" charge:

mcm4_leds.jpg

I'm not sure if there should be more green lights on full charge? After riding it for about 8km the battery shows 30% charge left (two red leds) and it also frequently starts to beep when going uphill (voltage drops too low?) so I'm not getting anywhere near the advertised 30km+ range. I opened the wheel and checked the battery and it says 340wh on the sticker on it.

Any idea what is wrong with the wheel and can I somehow fix it?

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Can you measure the voltage of the charger with a voltmeter?

as a general note, the real mileage will never be as high as the advertised by manypufacturer for ANY brand. Id hope to expect about half of the advertised range. Also this depends on your weight.

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2 hours ago, Cloud said:

Can you measure the voltage of the charger with a voltmeter?

to me it also looks like a busted (or wrongly calibrated) charger

although could be faulty battery cells too. if the charger voltage is 67.5, then the next step would be to unwrap tge battery and check voltage across cells (not for the faint hearted) - or if you can arrange that - warranty replacement

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I'm sure there should be more green lights on full charge, at least one more (I have exact same euc, but seen it yesterday so cannot remember). 

In the pic is my voltages  without the charger being connected to the EUC.

20160502_121715[1].jpg

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Even if my charger outputs only 66.5V I don't think that explains why the EUC only charges to 62V. If I up the charger voltage by 0.7V to 67.2V that probably doesn't make the EUC suddenly go from 62V to 67.2V, right?

I don't feel comfortable opening the battery pack. I guess I could still measure the voltage from the charge lead that connects to the battery pack from the plug on the shell, but I need to make some plug or adapter for measuring that. I don't think I can do it otherwise without shorting it by accident.

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14 minutes ago, muumi said:

 

Even if my charger outputs only 66.5V I don't think that explains why the EUC only charges to 62V. If I up the charger voltage by 0.7V to 67.2V that probably doesn't make the EUC suddenly go from 62V to 67.2V, right?

 

Why don't you try it first?

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On 1.5.2016 at 8:00 PM, muumi said:

I recently bought a Gotway MCM4 340wh and it doesn't seem to charge above 65%-70% (~62.25V) according to the android app.

...

After riding it for about 8km the battery shows 30% charge left (two red leds) and it also frequently starts to beep when going uphill (voltage drops too low?) so I'm not getting anywhere near the advertised 30km+ range. I opened the wheel and checked the battery and it says 340wh on the sticker on it.

Any idea what is wrong with the wheel and can I somehow fix it?

After driving, reconnecting the wheel to the charger it again charges up to 65%-70%?

23 hours ago, muumi said:

I plugged the charger to the wall and measured the voltage from the adapter that connects to the EUC (pins 1 and 3) and got 66.5V. This was without the charger being connected to the EUC.

 

1 hour ago, muumi said:

Even if my charger outputs only 66.5V I don't think that explains why the EUC only charges to 62V. If I up the charger voltage by 0.7V to 67.2V that probably doesn't make the EUC suddenly go from 62V to 67.2V, right?

I don't feel comfortable opening the battery pack. I guess I could still measure the voltage from the charge lead that connects to the battery pack from the plug on the shell, but I need to make some plug or adapter for measuring that. I don't think I can do it otherwise without shorting it by accident.

The ~62V are from the android app? ... So they could be any number and not have to be the exact battery voltage ... Don't know how exact the send values from gotway are - current e.g. is(was) very inaccurate. So i would not really trust them...

If you know how to open your wheel and you are not reluctant to do so, you could quite easily measure the battery voltage at the battery pack connectors without opening the pack.

If this voltage confirmed by the multimeter is ~62V the charger is presumably not your only problem. But I'd assume that the voltage will be quite near to the 66,5V and the charger calibration could solve your probs.

Did you buy from a local reseller or have friends with another gotway charger (Kingsongs could have quite exactly the same charger, too?) that would be the easiest way to try out first - without opening anything...

If, on the other side this does not help, or your battery pack voltage measing confirms the ~62V of the app you'll quite for sure have some battery pack problem (beside the miscalibrated charger)

In http://forum.electricunicycle.org/topic/3831-unexpected-shutoff-battery-failure-ips-i130/?do=findComment&comment=39833 you have the "story" of a battery pack repair.

 

.... Or you just go the way to ask your reseller for a replacement charger and if this wont change your situation for a replacement battery pack...

Ps.: Just in case your problem comes from a "bad" battery cell be carefull while driving in the meantime - the bms could cut quite anytime due to low cell voltage...

 

 

 

 

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  • 2 years later...
On 5/1/2016 at 2:00 PM, muumi said:

I recently bought a Gotway MCM4 340wh and it doesn't seem to charge above 65%-70% (~62.25V) according to the android app. Even if I leave the charger that came with it plugged in for hours, it won't raise above this.  The light on the charger stays green, so it won't charge further. Here's what the LEDs look like on the wheel when it is at "full" charge:

mcm4_leds.jpg

I'm not sure if there should be more green lights on full charge? After riding it for about 8km the battery shows 30% charge left (two red leds) and it also frequently starts to beep when going uphill (voltage drops too low?) so I'm not getting anywhere near the advertised 30km+ range. I opened the wheel and checked the battery and it says 340wh on the sticker on it.

Any idea what is wrong with the wheel and can I somehow fix it?

Same here

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