electric moped fault

billyboya

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Aug 10, 2016
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Well something really wrong here as I just wired up my 48v charger as both wires had came loose so I asked which is pos and negative out of the 2 wires brown and blue you nealh said brown so put brown to + blue to - on the Jack plug plugged it into battery charge port. Green light was on but it’s only 49.4v It should be 54v. Also I don’t seem to get a reading from the discharge port . I have not as yet opened battery case but will tomorrow. But it seems nealh you could be right about my moped problem as u said it could be the battery. As I didn’t seem to get any readings on moped with battery plugged in. And that battery is only 9 months old. I also do think I need a better charger with a permanent Jack plug on it not with 2 screws as I find the wires tend to get loose

can you suggest a good charger with Jack plug
 

soundwave

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May 23, 2015
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id test the cell banks b4 spending any more money or it will be going down the drain.
 

billyboya

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soundwave

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if it wont fully charge then something is wrong with the bms or one of the cell banks has a problem or a cell could be dead.

 

billyboya

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Aug 10, 2016
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if it wont fully charge then something is wrong with the bms or one of the cell banks has a problem or a cell could be dead.

well this is most weird as just plugged in battery and ignition came on display all lit up but throttle won’t work so no good yet. But this battery like I said is only 9 months old. And I can’t access the bms on battery as would mean me cutting blue tape and would loose warranty I would think
 

soundwave

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id contact the seller then and see what they say, did you get the charger from them as well?
 

Nealh

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Aug 7, 2014
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Battery warranty is very suspect when bought form overseas, there is no way to send them back legally.
The battery came form Aliexpress and one never knows how good they will be or what cells are used, the seller is your best point of call first for any readress. One has to bite their tongues and accept that these cheap batteries will likely be short lived.

As I had already suspected, the battery is likely the cause and I suspect a cell bank is poorly or the BMS is shot, the only way of knowing is by opening it up once contact has been made with the seller and come copromise has been reached.
 

egroover

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Aug 12, 2016
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billyboya, I wouldn't be opening your battery unless you know exactly what you are doing. Wouldn't want you to get hurt if you shorted it out or some other problem to add to your woes. As Nealh says, try and work things out with the seller either a refund or similar.
I've got to say I admire your perseverance, that moped is determined to break you, would of been in the canal months ago if I owned it lol
 

Nealh

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Aug 7, 2014
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My take is the style and weight of these so called pedelecs means they are not suitable for the usage, despite the pedals which in use are near to useless and the 250w rating.
Any battery needs to be a very good one using quality cells to maintain the 25/30a current draw and likely in all honesty way more then 30ah is needed for decent operation.

I see there is a 30 model on ebay for sale at £250, I somehow don't see this bike recouping anywhere near what billyboya thinks he may get but one can always hope.
 

billyboya

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Aug 10, 2016
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My take is the style and weight of these so called pedelecs means they are not suitable for the usage, despite the pedals which in use are near to useless and the 250w rating.
Any battery needs to be a very good one using quality cells to maintain the 25/30a current draw and likely in all honesty way more then 30ah is needed for decent operation.

I see there is a 30 model on ebay for sale at £250, I somehow don't see this bike recouping anywhere near what billyboya thinks he may get but one can always hope.

do you have a link to that 1 on ebay, Not that I'm going to buy it lol as had enough of this model 15. and yes I have been thinking about ringing a scrap dealer, But something says carry on as I have spent a lot of this moped. But doubt I will get much, But have to sort it 1st before trying to sell it. I'm glad at least I have sold my old electric bike. as I paid £250 for its 5 years ago and got £220 for it cash.

I've just opened up my battery case, and here is battery, I checked voltage its 49.5V which seem very strange as I had charged it up to 54V. I have noticed that kettle type discharge plug the terminals are a bit loose. I think I do have a spare one so if I can find it I will change it. wether its worth the bother I dont know yet.

Also when I plug battery into moped lead. then say check ignition wire what's on other side of fuse going to loom not back to ignition, place multimeter on 200V DC place black probe on some metal on moped. and red to end of fuse nothing happens no reading at all. yet the display is all lit up. I also tried same thing where controller power cable is nothing at all so I'm confused now

Also the bottom set of indicators work fine also horn plus also alarm which I find very strange as the alarm is plugged into controller yet throttle wont work well moped dont run i mean


IMG_2336.JPGIMG_2337.jpgIMG_2338.jpgIMG_2339.JPG
 
Last edited:

soundwave

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May 23, 2015
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it is called voltage sag and why the motor wont work this happens with cheap cells or a old pack has lost most of its capacity and just cant supply the voltage needed for the controller to work with the motor.

lights and display do not use much voltage and why they are working but not the motor so if you cant send the pack back to the seller the only option is to open the batt and start testing the bms and cell banks for low voltage.

the sheer waight of that bike means that batt has had a hard life but to get a batt and capacity that will last a few years will cost about 1000 quid or more with decent cells if jimmy made it. https://ebikebatteries.co.uk/

big heavy bike means big expensive batts so you cant skimp on the batt or well you now know what will happen if you buy stuff from china with no idea what cells they used and why they are cheap.

 

billyboya

Esteemed Pedelecer
Aug 10, 2016
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it is called voltage sag and why the motor wont work this happens with cheap cells or a old pack has lost most of its capacity and just cant supply the voltage needed for the controller to work with the motor.

lights and display do not use much voltage and why they are working but not the motor so if you cant send the pack back to the seller the only option is to open the batt and start testing the bms and cell banks for low voltage.

the sheer waight of that bike means that batt has had a hard life but to get a batt and capacity that will last a few years will cost about 1000 quid or more with decent cells if jimmy made it. https://ebikebatteries.co.uk/

big heavy bike means big expensive batts so you cant skimp on the batt or well you now know what will happen if you buy stuff from china with no idea what cells they used and why they are cheap.


Well is that 100% it is the battery, it was august 2021 I bought it. but had to wait a month for it to arrive. so say sept 2021 so only 9 months old

You say lights and display do not use much voltage. but isnt 49.5V enough to make motor run then. as I have been told no need to keep charging battery up to full each time do it when its about say nearly half used. I have to be 100% it is bad battery. as cant tell seller in china if I am wrong

btw whats that link for that single 1 battery looks like a AA
 

soundwave

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May 23, 2015
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only way is to test the cell banks voltage and the bms so you will have to cut open the batt to test it.

i doubt you will get anywhere with the seller but sending it back to china tracked postage will cost a fortune if you can find anyone to send it from the uk as cant ship that via plane as it is to big.

you could send it to jimmy as he could then try and fix it and get the bike sold but might not last much longer if the cells capacity has gone.
 

Nealh

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Aug 7, 2014
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If an average was taken then 49.5v mean seach cell group is at 3.807v or approx. 55 - 62%.
However one can only assume this is what may be so, if it were so then the bike should run.

But if one cell group is out of balance it possibly could be 0.2, 0.3v or more out of balance which would mean that one group could be at 3.4v - 3.6v, it wouldn't take much for voltage sag to send that cell group beyond lvc and cutting off.
A battey pack is only as healthy as the weakest cell or cell group.
So unless a definitive answer is known, the unknown remains jsut that and we can only summise whay is a happening with the battery.

So much has happened to this bike that the fault could be any where, it may even be back in the motor and the Hall sensors you replaced.
Carry out a Hall test again to see they read 4.3v - 5v and they switch when turning the motor by hand and also carry out the mosfet tests again, which you have done all before in your main erider thread.
These two tests would rule out two possibilites.
 

billyboya

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Aug 10, 2016
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If an average was taken then 49.5v mean seach cell group is at 3.807v or approx. 55 - 62%.
However one can only assume this is what may be so, if it were so then the bike should run.

But if one cell group is out of balance it possibly could be 0.2, 0.3v or more out of balance which would mean that one group could be at 3.4v - 3.6v, it wouldn't take much for voltage sag to send that cell group beyond lvc and cutting off.
A battey pack is only as healthy as the weakest cell or cell group.
So unless a definitive answer is known, the unknown remains jsut that and we can only summise whay is a happening with the battery.

So much has happened to this bike that the fault could be any where, it may even be back in the motor and the Hall sensors you replaced.
Carry out a Hall test again to see they read 4.3v - 5v and they switch when turning the motor by hand and also carry out the mosfet tests again, which you have done all before in your main erider thread.
These two tests would rule out two possibilites.
Well Nealh I was really hoping. I didnt have to do all that again. dam bloody moped. should never have bought it. But its just that I got so far by trying to fix it. it gave me some more hope. Im no hurry to get it sorted well am in a sense to get it out of my dam flat. and in my shed ready for selling. But no point if its not running again.

it just sods law as it ran once for say 1/2 mile, after 3 months fixing it.

then cable twisted lol. so another month sorting it all

fitted new cable new hall sensors etc etc. torque arms even special Loctite glue on nuts. ran again for say a good 3 1/2 weeks even went on a good long trip at night to visit my nephew. a good 14 mile there and back np at all. now bugger me it cuts out 500 yards from my home. and its back to being fixed again.
 

soundwave

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May 23, 2015
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look at these if you think ur having a bad day :eek:


also the shimano e8000 motors are craping out with under 2000km on them and unfixable and non serviceable and a new one is £900 if you fit it your self.
 

billyboya

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Aug 10, 2016
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look at these if you think ur having a bad day :eek:


also the shimano e8000 motors are craping out with under 2000km on them and unfixable and non serviceable and a new one is £900 if you fit it your self.

hahhaahah having a bad day ya having a laugh LOL Im having a frigging bad year. well about 5 months frigging bloody moped.

giphy.gif
 

soundwave

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May 23, 2015
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those bikes cost between 8-10k depending on spec fook that lol