KT-LCD3 shows zero battery charge while voltage is 54.5

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hardW   10 µW

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KT-LCD3 shows zero battery charge while voltage is 54.5

Post by hardW » Jun 14 2018 4:29am

Hi
I've got a following issue with my ebike: KT-LCD3 shows zero battery charge while voltage is 54.5 (according to it) and motor does not spin (both with throttle and assist). Controller is KT48ZWSRD-BSK11L, bettery Sinlion 48V 15.6Ah fully charged, motor is Bafang BF RMG06 48V500W(10). All the wiring seems to be intact. What can it be? Run out of ideas(

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wturber   100 kW

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Re: KT-LCD3 shows zero battery charge while voltage is 54.5

Post by wturber » Jun 14 2018 2:19pm

Sorry to ask the likely obvious question, but have you unplugged the battery, waited a bit, and the re-plugged it in?
"Commuter - DC Booster"
Iron Horse 3.0 hardtail - 48V / 1000W / 470rpm generic Chinese DD Hub motor (ebay)
8 x 36v 4.3ah 10s 2P battery packs - 1500W 30A DC Boost Converter delivers 54v and about 1000 watts peak
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hardW   10 µW

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Re: KT-LCD3 shows zero battery charge while voltage is 54.5

Post by hardW » Jun 14 2018 2:29pm

Sure. It was first thing I've tried.
Also I want to mention that:
1) This bike was working fine for ~300Km
2) Last ride I've drained battery so that motor was not responding to both throttle and assist. But voltage was ok for display (and probably controller) to work. I've rode few miles on pedals. Then after ~10h I've plugged it in to charge.

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Re: KT-LCD3 shows zero battery charge while voltage is 54.5

Post by amberwolf » Jun 15 2018 12:25am

Controller could have a problem sensing the voltage and/or sending the data to the LCD.

I have a Fusin controller / LCD (made by LiShui) set, where one controller works normally, and the other (using hte same LCD) doesn't send voltage or speed data to the LCD. The LCD does control the PAS modes/etc of the controller, either way, so I suspect something with the controller's transmit-data line, but never got to testing that (since the other controller works normally).

hardW   10 µW

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Re: KT-LCD3 shows zero battery charge while voltage is 54.5

Post by hardW » Jun 15 2018 3:40am

Finally I've managed to shake controller and heard something loose inside it. It was resistor :shock:
Where was it soldered I can't yet figure out. I guess I'll need photos or schematics of this controller
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eee291   10 kW

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Re: KT-LCD3 shows zero battery charge while voltage is 54.5

Post by eee291 » Jun 15 2018 4:21am

:arrow:
Last edited by eee291 on Jun 15 2018 4:36am, edited 2 times in total.

hardW   10 µW

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Re: KT-LCD3 shows zero battery charge while voltage is 54.5

Post by hardW » Jun 15 2018 4:33am

Yeah those look most loose to me too. But they marked for different resistors - R63 and R64. Need to be sure.

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eee291   10 kW

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Re: KT-LCD3 shows zero battery charge while voltage is 54.5

Post by eee291 » Jun 15 2018 4:35am

Image
Image

I just opened my Controller

I guess my controller is a newer version.

But when I look at your R63 solder pad it was definitely in there.

hardW   10 µW

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Re: KT-LCD3 shows zero battery charge while voltage is 54.5

Post by hardW » Jun 15 2018 4:50am

Thanks. Our controllers have one in common: instead of two resistors (according to drawings), they have one. Guess this can be an issue, since two small resistors can have better cooling that one big. So I'm thinking about replacing it with two small. Unfortunatelly I don't see any other way not to make it happen again (unsoldering because of overheating).

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eee291   10 kW

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Re: KT-LCD3 shows zero battery charge while voltage is 54.5

Post by eee291 » Jun 15 2018 5:01am

I don't think it overheated. If you look at mine, the resistor looks really badly soldered. I might apply more later.

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Re: KT-LCD3 shows zero battery charge while voltage is 54.5

Post by docw009 » Jun 15 2018 11:07pm

Looks like you figured it out already, but here's my old PSWpower 20A controller.
P1650353.JPG
P1650353.JPG (92.03 KiB) Viewed 235 times
Brown-black-black. What is that ..10 ohms?

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