Water damaged controller

[iBlaze]

I have a lcd8s display and a KT squarewave 48v 1500w controller, and 60v battery.
When i turn on the ebike the battery indicator starts flashing, and i cant throttle.
This happend after i was riding in the snow.
Everything worked well until now, for like 4 months.
I dont know what is damaged, i have checked the components near the damage with a multimeter and they work fine.
I have another broken controller which i can swap out parts for, i just dont know whats wrong with it.
Can someone help?

 

[indianajo]

I have had single board computers steam cleaned, washed in DI water, dried off at 130 F,and returned to service. I doubt if water damaged this board. No sign of conductive deposit in the picture. Salt or calcium deposit will take out small electrical parts frequently.
Displays are more fragile, the LCD device is not well sealed.
I have had a bike controller lose contact between the PAS sensor at the edge, and the computer that processes the signal. 3.5 years of age. Bad via (plated through hole) I imagine. Siince there is no English datasheet on the controller IC, no telling which pin was supposed to receive the signal.

 

[PCeBiker]

I have a lcd8s display,..
When i turn on the ebike the battery indicator starts flashing,..

It sounds like the controller thinks the battery is low and it has shut down.

Check the output of your battery for 60V.
Check for a blown fuse in the battery, if it has no output.

Check the battery power input to your controller to make sure 60V is getting there.
Check all connections. Look for broken wires.

 

[harryS]

I wouldn't bother, but that's me. I've had several get wet inside and quit working. You can get corrosion under a small SMD component and not even see it.

 

[iBlaze]

View attachment 170144

It sounds like the controller thinks the battery is low and it has shut down.

Check the output of your battery for 60V.
Check for a blown fuse in the battery, if it has no output.

Check the battery power input to your controller to make sure 60V is getting there.
Check all connections. Look for broken wires.

I know the battery works because in the first few seconds the display is on, the throttle works and the hub motor spins, but then the indicator light starts flashing.

 

[iBlaze]

I will try to wash the controller in isopropyl alcohol and then dry it off, hope it works and wont have to try and swap the SMD components.

 

[Slaphappygamer]

A 60v (16s) battery will be about 67v on a full charge. I see caps, on your controller board, are 63v. I know you say trouble started after riding in the snow, but I don’t know how those caps could have been operational under a fully charged 16s battery.

If that is truly a 48v controller, I would think you’d have an “overcharge” failure. Perhaps now is the time to get a controller rated for a 60v battery. You might get lucky if a new KT 60v controller will work with your same display.

 

[iBlaze]

A 60v (16s) battery will be about 67v on a full charge. I see caps, on your controller board, are 63v. I know you say trouble started after riding in the snow, but I don’t know how those caps could have been operational under a fully charged 16s battery.

If that is truly a 48v controller, I would think you’d have an “overcharge” failure. Perhaps now is the time to get a controller rated for a 60v battery. You might get lucky if a new KT 60v controller will work with your same display.

It has worked fine for 4 months of riding, my battery charges to 67.2 volts, i thought this would be an issue when i was buying the controller but it turned out fine.
If i have to get a new controller i will get a 60 volt 2000w controller. If i fix this one i will make sure to fully waterproof it myself.

 

[spokewrench]

I put a 35 AMP controller on a bike. I don't know the model, but it came with a KT-LCD8H display. One morning I rode half a mile with very little motor assistance to a store. As I started back, I stopped at an intersection to let traffic pass. Then it wouldn't respond to the throttle to get under way. I hopped off and walked it across. Then it ran fine for the rest of the day. It happened again under the same circumstances a few days later.

On that bike, the controller was mounted below the frame where it was exposed to mist and droplets picked up by the front tire, and I had ridden on wet pavement a few days before the first incident. My theory was that there was moisture in the box, and on some mornings there would be condensation on the power transistors. They would warm fast, causing it to evaporate. When I parked for a few minutes at the store, what evaporated from the vicinity of the power transistors would condense on more sensitive circuitry that was still cold. When warmth from the power transistors reached the sensitive stuff, it would dry and I'd be fine.

I opened the box and found no moisture. That didn't mean there wasn't a little hiding somewhere. I treated it to several minutes of hot air from a hair dryer. It was fine until the next time I rode on wet pavement, weeks later. The hair dryer fixed it again. This time I sealed the box with RTV. I've had no more trouble.

 

[iBlaze]

Thanks for all the help, i solved it, the water coroded a hole in the pcb and trace was connected to the display and the resistor to the right.
It took me some time to test all the connections but i did it, thank you for all of your help!

 

[Slaphappygamer]

Excellent!

 

[tomjasz]

I know the battery works because

Not a reliable method. All eBike users ought to own a multimeter. That will confirm voltage.