Author Topic: problematics ; what to do ?  (Read 4294 times)

Offline niceguysteve

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problematics ; what to do ?
« on: November 03, 2011, 07:39:37 PM »
Hello to all ;
  Got a new MPII in the spring and early summer got the new 48V 10amp battery both from Gary at Golden Motors Canada. They ran great til Oct 12 . A few weeks earlier I had to bypass the switch on the battery as it had intermittant shorting and then gave out. All ran well until the rig suddenly shut off and when reconnected would only go a few yards then shut off again . I replaced the connection between the battery plug and motor and all was good for a day or so . Then during heavy rain in stopped running at all . Gary mailed me a new internal controller which I installed with some help from a pro ebike repair guy . It ran with the old battery (12amp 48V )but not the new one . I replaced all connections between the battery and motor . There was a obvious short in the 2prong connector that connects to the 2prong from the motor so I removed both and soldered,taped, silicone rubbered and spliced the (2) wires from the
>motor to a new cable . I put good quality 3prong AC plugs between the battery plug and splice job so as to have a disconnect that can tolerate usage. Once I got the wheel back on everything ran great with the new battery for two days . Here is a synopsis of the present situation.

A) the new 10amp  battery doesn't charge either on the older charger for 20minutes or on it's charger overnight . It tests at 40v both output and input and when either  charger is      connected
output is at 50v .
It had this problem last week but after sitting  for a few days it showed 50V and powered the bike well on Sat. and Monday ..... 
  B) the old battery tests 48V and when hooked it makes the wheel spin well while on the kick stand . The cruise and regen brakes also all good . Off the kickstand wheeling the bike it cuts out b4 I get  5 yards . It does kick in with lots of power but only for a few seconds .
 This was the first symptom (running with the new battery ) a day before the rig stopped completly .
 Seems to me that
There are two problems . Both the new battery and also motor and/or  connections.
   
 For the motor I think replacing the cable that comes out of it is the next step .(is this the harness ?) It is the only original wire between the battery and the motor.
  Perhaps running the two batteries parallel will help the battery to restart doing it's job.
  Gary has been very very helpful in responding to my many emails with advice and also offered some waranty support but any aditional advice would be greatly appreciated . I actually know little about eelectronics other than what I 've learned keeping the ebike running . Also sorry to have posted so little on the forum while things were running great . THX niceguysteve  Toronto/Canada

Offline e-lmer

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Re: problematics ; what to do ?
« Reply #1 on: November 03, 2011, 09:29:19 PM »
This sounds like a bad cell in the pack.

Since you bypassed the switch anyway, you know how
to open the battery pack.
Open it up and measure the cell voltages.
I very one is dead.

Offline GM Canada

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Re: problematics ; what to do ?
« Reply #2 on: November 03, 2011, 10:16:54 PM »

 For the motor I think replacing the cable that comes out of it is the next step .(is this the harness ?) It is the only original wire between the battery and the motor.
  Perhaps running the two batteries parallel will help the battery to restart doing it's job.


Hi Steve,

Sunday night I went to plug in the chargers into my pair of batteries and ended up sticking one in at a bad angle . I shorted the plug with a big spark. The charge port now needs to be replaced as it melted pretty bad. Since I have not had time to change it and still want to ride to work I am still using it. I am leaving both batteries turned on and both are wired parralel to the controller. For the last 3 or four nights I have only been using one charger plugged into the good port on one battery and the second battery is being charged through the parralel conection in the front. This has worked fine and both batteries end up being charged fine.

The reason I mention this is if you could parralel your batteries in the front and try charging them both with one charger plugged into the working battery. Leave it over night and then check the voltage on both batteries when the charger is done. I would use the original charger plugged into the original battery for this test. If the second battery gets a good test take it for a good ride and see how it works. it may be the bms preventing it from taking a charge and this could be a way of testing it.

Of course this may harm other cells if one is dead. but the fact the chargers will not turn on when the battery is at 40 volts seems charging related rather then cell related.

Anyway take this with a grain of salt as my methods are a little brutal at times and usually when I think I know somthing it is quickly pointed out that I am wrong :)

Gary

Offline niceguysteve

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Re: problematics ; what to do ?
« Reply #3 on: November 20, 2011, 11:26:36 PM »
Brutal but effective . The parallel wiring worked as far as charging is concerned . Unfortunately once charged and testing at more than 50V the rig still did not run further than the alley I live in. Gary came thru big time and I'm up and running . The story is in my next post...
« Last Edit: November 21, 2011, 12:39:51 AM by Bikemad »