Bike trouble

[Pure]

I went on a 10 mile ride today. The longest so far on the new bike. I'm running a X5304 with the 25-72V analog controller with a CA. Currently running a 48 volt 20 amp LiFePO4. The bike did fine. I get to my destination and turned the bike off. I left the battery plugged in and it sat for about an hr. When I went to leave the throttle was WO as soon as I turned it on. The bike literally jumped out of my hands. I caught it so no damage there. Checked the throttle and everything looks ok. Unplugged everything then replugged it back together. Battery included. And same thing happened. Soon as I hit the power btn the bike tried to go! This happened several times until finally when I plug the battery in I get the arc but no power to the bike. CA doesn't come on at all. Voltage check and the battery reads 52 volts (after 10 miles) and then drops to 0 as soon as I plug it in. So I guess the BMS is tripping? What the hell is up with the WOT and now the BMS? Help me out here as I have no clue.

Thanks

Side note, the arc at plug-up is much more violent now, even with the throttle unplugged. The battery charged for about 2 hrs and is reading 56 volts, until plugged in.

 

[Ypedal]

Is the throttle an LED type ? and did it rain ?

 

[Pure]

No LEDs, It's a thumb throttle purchased from ebikes.ca. No rain. It's been nice here in Florida 8)

 

[snowcrow]

Sometimes the ground pin on the throttle plug gets pushed in and it will go WOT.


Blessings, Snow Crow

 

[nicobie]

Sometimes the ground pin on the throttle plug gets pushed in and it will go WOT.


Blessings, Snow Crow

I've had that happen too.

Nick

 

[Pure]

Sometimes the ground pin on the throttle plug gets pushed in and it will go WOT.


Blessings, Snow Crow

So what should I look for? And why would this cause my BMS to trip.

Later today I plan on soldering up a BMS bypass plug to be able to do some testing on the bike. Is this a bad idea?

 

[dnmun]

bad idea, take the throttle apart. or replace it with another one to verify it is the throttle, sounds like it is.

 

[nomad85]

bad idea, take the throttle apart. or replace it with another one to verify it is the throttle, sounds like it is.

I agree, if you bypass the bms you may damage your battery, no doubt the bms tripped because your bike wanted to go WOT, on a 5XXX that's a lot of amps.

 

[Pure]

If it's the throttle, wouldn't unplugging it from the controller stop the BMS from tripping? That's not the case. The BMS trips even though the throttle is discoed from the controller.

 

[dnmun]

what do you mean 'the BMS' trips? do you have voltage at the output from the battery?

 

[Pure]

Voltage check and the battery reads 52 volts (after 10 miles) and then drops to 0 as soon as I plug it in. So I guess the BMS is tripping?

 

[nomad85]

Voltage check and the battery reads 52 volts (after 10 miles) and then drops to 0 as soon as I plug it in. So I guess the BMS is tripping?

The bms usually trips when too much amperage is drawn from the battery or the voltage is below the LVC. You would have to apply some throttle for the BMS to trip(as far as I know). Sounds like something else may be going on, I wouldn't bypass the BMS if you want the battery to last.

 

[snowcrow]

If it's the throttle, wouldn't unplugging it from the controller stop the BMS from tripping? That's not the case. The BMS trips even though the throttle is discoed from the controller.

I would check the power plug on the controller with an ohm meter. It should read infinity with the controller switch off, and about 5.5k ohms with it on.

If it reads 0 ohms with the switch off, I would say you may have a shorted cap

BTW you should have a fuse between the battery and controller

I'm assuming there isn't one because it should have blown before tripping the BMS :?

If there had been a fuse, and it didn't blow, you would then know its most likely the BMS that toast :?

The BMS is ment as a last line of defense and shouldn't really be used as a fuse :wink:

I hope that some of this helps!

Blessings, Snow Crow

 

[dnmun]

"plug it in" ? when your battery is charged up, and sitting there, what is the voltage on the 2 wires coming out? if you don't already have fuse in line, this is a good time to finally add one. that could prevent your controller from being damaged too. but first things first. charge up the battery and measure the voltage on the 2 wires. if you can measure the input impedance to the controller that will help too. remember to zero the ohms scale first and don't measure resistance while there is electric power on the wires.

 

[Pure]

when your battery is charged up, and sitting there, what is the voltage on the 2 wires coming out?

It now reads 56 volts., it took a charge after the incident. Tomorrow I plan on getting a small 24 volt SLA pack so I can do the needed testing y'all are telling me to do. I had a brand new 48 volt SLA "test" pack that got smoked after 2 rides. SLAs don't like X5s.

Yes a fuse is a good idea. I had a small 30 amp that went pop first time out. I've looked around at auto part stores for a larger fuse but everything they have larger than 30 amps is this huge blade fuse that they just don't have separate wired plugs for them to work with. So any help on finding a good 60 amp fuse would be helpful. BTW to act as a fail safe I set the current limit on my CA to 45 amps. Anymore than that and it causes the BMS to trip after a long ride. I know the BMS works as unplugging the pack and then plugging it back in resets it every time.

 

[Pure]

Hooking up 24 volts of SLAs made the controller's magic smoke slip out. I guess I'm sending it back to e.bikes.ca..Waiting now to hear back from them. So far their customer support has been great.

 

[dnmun]

i thought you had a 48V controller? 24V is not enuff for it to work.

can you take pictures so we have some idea of what you have? did you buy a kit from justin?

 

[Pure]

My digi is down ATM so no pics. The controller is the 24-72V 35A analog controller. http://www.ebikes.ca/store/photos/C7235SI.jpg 19 volts is the minimum needed to power it up. I run a 48 volt bat on it but just used the 24 volt for testing.

Yes the kit came from Justin.

 

[ElectricEd]

I had similar symptoms when I finally assembled my bike with the bits that I purchased from Brett White. It was caused by a short from daggy strand strands on a main phase drive wire that didn't go through the hole in the PCB. The bike would lurch forward before the BMS would cut out. This occurred a few times while I was trying to figure out what was going on. Four FETs eventually blew, creating a short across the supply. When I tried connecting the battery after that, the splatter from the arcing almost destroyed the contacts on the 50 Amp Anderson connectors. Use an ohmmeter to check the resistance of the controller. If it is almost a dead short, you have at least 2 blown FETs.