Symptoms of a loose ground (black cable) to battery

Deepkimchi

1 kW
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Jul 3, 2007
Messages
365
Location
S Korea
Well, riding to the A base today I got thru the gate, then about a 1/4 mile and hit some bumpy road.

Poof, power gone. Started checking the connections out, especially the battery negative cable (black).

Could not get it fixed. Symptoms - with the controller off, the Cycleanalyst would come back up, and give 39V, turn the controller on, voltage would fall on the CA then it would blink out. Sometimes it would blink off and on, go to 19V, up-down, then out, without me touching or moving anything.

I unplugged the red batt cable and pedaled home. Oh Lord- 40 extra lbs on the bike up and down hills, and out of shape from Ebiking - jeesh, almost puuked.. :oops:

A funny thing - pedalling was generating 23-25 V. If I slowed up the voltage went down. :?:

Anyway after work I changed the cable (slightly longer one) and Anderson connector - all okay now :lol:
 
A loose connection of the +ve cable to the battery could also have such symptoms.

At what speed was 23-25V generated by pedalling?
 
Pedaling totally sucks.


Deepkimchi said:
A funny thing - pedalling was generating 23-25 V. If I slowed up the voltage went down. :?:

As your motor turns, it acts like a generator. With the battery disconnected, the juice from the motor will get rectified by the body diodes in the controller FETs and start charging up the main capacitors in the controller. You can easily generate enough to power the controller circuits and a CA.

If you go fast enough to generate more than the battery voltage, you can recharge the battery :wink:
 
Wasn't pedaling too fast, about jogging speed to generate 25V. Hopefully my new anderson connection will hold better. How do dean connectors hold?

Also got to get something better than bungees to hold the toolbox (with batteries).

Really have to pull them tight, by wrapping them around the toolbox handle and then lead them to the hook on the bike rack. Need some kind of racheting device on a strap. Takes me about 10 minutes to attach the toolbox to the bike and tape the connectors (each morning).

DK
 
Hi

Glad you got your bike working, I used roof rack straps to hold my batts down like this one, use 2 of them, cut them down then melt the frayed ends with a cigarette lighter, work like a charm.

Knoxie

MidProductImages%5CWindSurfing%5CRoof%20rack%20pads%20and%20straps%5Caccess_basic_roof_rack_strap_08.jpg
 
Deans work like a wall plug, pressure fit. They have a spring to keep pressure. I've run them on High-G RC aircraft without ever having them seperate. I run a mix of deans and power poles on my bike, and have never had a failure on the deans, but have had the powerpoles seperate over hard bumps before.
 
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