gotmy a2b work down 2 streets then dead76v

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alswiseowl
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gotmy a2b work down 2 streets then dead76v

Post by alswiseowl » Jan 07, 2018 3:11 am

what could be the problem with my bike..
I just got my a2b to work after all the throttle connection issue, then this..

I plugged my 76v rig up, powered down 2 streets then I look at the cycle analyst & I notice the reading drop down to 46v,powe cuts out, then I twist, rises again to 84vish,get about a metro then cuts out completely,even the cycle analyst goes blank whilst the battery is still plugged in..whats going on..could it be the temperature cut out, but for only 100meters,or is the wiring combo wrong again..nothing worst than buying a brand new item for good money swell as bike aint cheap..I really feel ripped off with my purchases :roll:
could any one add tier opinion in id appreciate it thanks.

alswiseowl
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Re: gotmy a2b work down 2 streets then dead76v

Post by alswiseowl » Jan 07, 2018 6:37 am

I should add, that after coming back home from my 200metre road of happiness then to what is going on.nothing
I recharged my battery pack to make sure it was fully charged up then everything came back to life
the cycle analyst show 86v took it for another test run on the 200watt legals I have a offroad option which will give me the full 60amps.
but still I only got 500metre from home then then cycle analyst shows 46v then 66v then 84v then cuts outs..I wait then 15seconds later the cycle analyst turns on I twist I take of this time a couple of meters..
I reckon the controller is too powerful for the motor

so I think my options is to either swap the motor to a 5kw one or dum down the controller to like 40amp
whats your thoughts.where the cheapest 5kw motors that will run with the crystallite controller..
thanks
least nothing blown, it just doesn't run for more than 5minutes :roll: needs the blue pill Neo

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amberwolf
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Re: gotmy a2b work down 2 streets then dead76v

Post by amberwolf » Jan 08, 2018 2:53 am

Anytime the battery cuts out like that, it means that it's BMS is shutting off the pack output.

It does that if the voltage of a cell (group) drops below LVC, which can happen with a pack that is not balanced (which may show fully charged, but with different cells at different voltages, some higher than full and some lower), or with defective cells that can't support the current draw without lots of voltage sag.

You can use a voltmeter with it's probes across each cell group in turn, to test under load (while riding, or wheel offground, or with a test load (lots of posts/threads about heaters/etc as loads) and watch for which groups drop in voltage more than others.

Some BMS also have a current limit, which will shut off pack output if it is exceeded. You'd have to know what the limit is, and see what your system is pulling to see if it exceeds that.

There's at least hundreds of threads about testing batteries; I'd go look thru some of those and follow the procedures to test yours.

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dogman dan
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Re: gotmy a2b work down 2 streets then dead76v

Post by dogman dan » Jan 09, 2018 8:54 am

YEP, its your battery that is the problem. Bear in mind, you might be just beating a perfectly good battery to death, if your motor and controller are big enough. Sounds like they are gigantic.

But more likely, something is not right in the battery. bad cell, or perhaps just a broken or poorly connecting wire leading to the bms, or even just really bad out of balance.

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fechter
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Re: gotmy a2b work down 2 streets then dead76v

Post by fechter » Jan 09, 2018 8:59 am

What's your battery configuration. I agree with the others it sounds like your battery can't handle the load and the BMS is protecting it.
"One test is worth a thousand opinions"

alswiseowl
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Re: gotmy a2b work down 2 streets then dead76v

Post by alswiseowl » Jan 12, 2018 10:00 pm

yes you guys were right, hyena industries found the problem to be the wrong bms for the battery pack..
so we've ordered a new bms,& luckily for me a have hyena who knows his stuff help me :wink: ..

now once the bms is fixed I will have to look at fabricating a battery housing, possibly thru abs or aluminum..

alswiseowl
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Re: gotmy a2b work down 2 streets then dead76v

Post by alswiseowl » Jan 16, 2018 6:55 am

hi people,

one question, now I know that my battery pack has been charged & discharged with the wrong bms
would there be any possibility that the battery cells could be damaged from that??
thanks

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fechter
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Re: gotmy a2b work down 2 streets then dead76v

Post by fechter » Jan 16, 2018 9:47 am

Yes, it's possible cells could be damaged. If any of the cells went to near zero volts and were then charged at full current, they could be damaged. If the cells went over 4.2v they could also be damaged. As long as the cell voltages remained in the healthy range, no damage should occur. It sounds like your BMS just had too low of a current setting and was tripping. That should not damage the cells.
"One test is worth a thousand opinions"

alswiseowl
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Re: gotmy a2b work down 2 streets then dead76v

Post by alswiseowl » Jan 16, 2018 8:57 pm

okmthanks fetcher,

might have to get someone to test to pack to make sure I don't have any damaged cells

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