possible voltage controller problem

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hogheaven
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possible voltage controller problem

I am having a problem with my BD-36 (brushed) ebike and would appreciate anybody's thoughts on what is the problem.

My bike just died when I was riding it last night. When I unplug the battery and then reconnect it, the bike runs for about 3 seconds and then dies. It'll actually run for alot longer if there is no weight load on the bike, but when there is a load, it dies very quickly. When it dies, the red light on the voltage controller goes dim. It gets bright again when the battery is disconnected, then reconnected, though.

When it was running last night, the motor was getting about 33 volts. The voltage going to the motor, when it is running, can be controlled (on and off) by the throttle.

Does this sound like a voltage controller issue. If so, does anybody have any suggestions about how to fix it, short of buying a new one?

Any help is greatly appreciated.

skylark
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Re: possible voltage controller problem

What is the charged voltage of your battery pack?

skylark
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Last seen: 15 years 5 months ago
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Re: possible voltage controller problem

Is it possible that any of your connectors has loosened up? Check the battery connections and other connectors.

hogheaven
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Re: possible voltage controller problem

I think it may simply be that the voltage output by the battery has drained too low. The motor requires 36V, but is only getting 33V. The full charged voltage of my battery is about 42V, and the bike was running great when the battery was fully charged.

I thought a motor could run at a lower voltage, but only slower, but somebody told me otherwise.

dogman
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Re: possible voltage controller problem

The low voltage cut off for the bd36 is pretty low, since I have run mine on 24v a few times. The symptoms you describe are just like mine when the batteries are dead, but usually that would be a lower voltage than 33. Does the low battery light go on before it quits entirely? A cooked battery pack could put out 33v resting, but basicly zero under load. If I understand you correctly, you just need to charge the batteries, but they should be putting out more than 33v when under load, If the batteries are still good. Sla's can be used up pretty quick if you have been running them all the way till the light comes on a lot.

Be the pack leader.
36 volt sla schwinn beach cruiser
36 volt lifepo4 mongoose mtb
24 volt sla + nicad EV Global

hogheaven
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Last seen: 15 years 6 months ago
Joined: Thursday, June 5, 2008 - 12:48
Points: 20
Re: possible voltage controller problem

I wasn't using my SLA battery. I have a Polymer Li-Ion Battery (37V 10Ah) from Batteryspace that I was using. I tried out my charged SLA battery this weekend, though, and it ran fine.

As for the low battery light, my throttle battery indicator hasn't worked for some time.

dogman
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Re: possible voltage controller problem

I thought it sounded like plain ol out of juice symptoms. I had a similar problem the other day, and upon opening the charger, it had some loose wires both on ac in and dc out. Suddenly all the wierd behaviour of my charger the day before was explained. The led would give the same signal if the battery is full, or disconnected. I would look at the charger and the plugs first of all. Hopefully your battery is ok, chargers are a lot cheaper.

Be the pack leader.
36 volt sla schwinn beach cruiser
36 volt lifepo4 mongoose mtb
24 volt sla + nicad EV Global

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