ADVICE/ADVICE - Think my battery has Finally died !!!

[bilabonic]

Hi All

I've been using my brothers 'cheapy' Chinese 48v(10/11Ah) bike for the last few months. Apart from having zero brakes and a rust bucket it's been fine !!!

I put it on charge last night and it was still still dead/flat ?

I do not have a Multimeter handy atm (all out on jobs) BUT i just tried a 36v charger (got a load of them from BMSBATTERY when i did a self build) and it showed RED led for power, then once i plugged it into the battery it showed GREEN led/fully charged (not another red LED as charging)....

This is the same for 48v Charger, shows GREEN/Fully Charged ?

It's Cyclocity branded/lockable battery..(Pics Attached/no key atm so could not access the contacts).

What is my CHEAPEST option to replace the battery ?

 

[bilabonic]

Just found this - https://www.cyclotricity.com/uk/no-charge-green-light

It DID make a slight 'crack/draw current' when i plugged in the PSU, was wet....God i need one of my Flukes !!

 

[flecc]

Yes, a sudden failure of this type is most often just a blown fuse or open connection.
.

 

[bilabonic]

Yes, a sudden failure of this type is most often just a blown fuse or open connection.
.

Yea, i'm not fussed on the fixed connection as well, the NEG term lokks burnt/barely attached tbh..

Not sure what inner diameter the + is ? I can measure the outer with a Micrometer.

 

[bilabonic]

Yes, a sudden failure of this type is most often just a blown fuse or open connection.
.

How would an OC cause it ? That's the same as not plugging it in ??

 

[flecc]

How would an OC cause it ? That's the same as not plugging it in ??

Yes of course, I didn't mean open connection into the battery, but an internal one in the BMS equivalent to a blown charge fuse.
,

 

[Andy-Mat]

Hi All

I've been using my brothers 'cheapy' Chinese 48v(10/11Ah) bike for the last few months. Apart from having zero brakes and a rust bucket it's been fine !!!

I put it on charge last night and it was still still dead/flat ?

I do not have a Multimeter handy atm (all out on jobs) BUT i just tried a 36v charger (got a load of them from BMSBATTERY when i did a self build) and it showed RED led for power, then once i plugged it into the battery it showed GREEN led/fully charged (not another red LED as charging)....

This is the same for 48v Charger, shows GREEN/Fully Charged ?

It's Cyclocity branded/lockable battery..(Pics Attached/no key atm so could not access the contacts).

What is my CHEAPEST option to replace the battery ?

Check if an internal fuse is blown. Replace if yes.
Check battery voltage with a meter, There is a minimum allowed, when below this, the charger will not charge! I only know that this is 28 volts for a 36 volt battery pack.
For a 48 volt it will be around 38 volts, guessing only.
To recover such a "state" will usually need a zero volt charger.
I do have some other "ideas" but they need someone technically top to try out......
regards
Andy

 

[bilabonic]

Hi Andy,

It is STILL working in pulses, so i don;t think it has passed the min allowed..Just need the key to take it off/open it..

What size/shape are these fuses, probably stupid current rating atsuch a low voltage !! I have packs of 20mm quick/slow blows from 100mA to 80A...

When i open it will i be greeted with a load of 1850's !!

Thanks for the reply..

p.s. I have had to resort a the Khallkoff..HATE the overpriced thing !!

 

[bilabonic]

Managed to borrow a 'meter' of sorts...

The main 30A fuse is OK (this is a an old car style shape) and is accessible easily via removing a grommet/seal on the battery case.

The battery is measuring 37.6v on the output side (2 connections that plug into the base).

The 36v gives out 42v as expected.

The 48v just makes the meter 'flash'...NO READING at all ??

Also when i plug the in the 36v charger and measure the output of the battery remains the same, 37.6v. The charger also displays a RED led (POWER ON) and a GREEN led (Fully Charged) ?

I only use fluke meters BUT the one i borrowed is giving these readings and i am 99.999% the 48v charger is faulty.

BUT why does not the 36v/42v charger work at all or alter the battery voltage when plugged in ?

Is the BMS stopping it to charge/alter voltage ??

Cheers

 

[wheeliepete]

The charger voltage is not reaching the battery pack for some reason, hence no change in the output voltage. Poss. faulty BMS or broken/loose wire somewhere in pack. There could be a charging fuse in the pack, but unlikely. If you are seeing 37.6v at output, then you may well have some faulty cells and suffering voltage sag under load, as the bike should still run OK at that voltage. How was the battery performing before this?

 

[bilabonic]

The battery has been fine, this seems to have only happened when i plugged in the 48v when slightly wet and had the 'surge'...

Surely getting a new 48v charger is a must to begin with as it has NO output.

Bike will still run in short pulses and show completely dead on the LCD display.

 

[wheeliepete]

OK, sorry, it's a 48v battery, have you looked for a fuse on/in the charger?

 

[Ajax]

The charger voltage is not reaching the battery pack for some reason, hence no change in the output voltage. Poss. faulty BMS or broken/loose wire somewhere in pack. There could be a charging fuse in the pack, but unlikely. If you are seeing 37.6v at output, then you may well have some faulty cells and suffering voltage sag under load, as the bike should still run OK at that voltage. How was the battery performing before this?

If the poster is trying to use a 36v Charger on a 48v battery, then it will not work.

The 36v charger is designed not to over-charge and so it should stop charging once 37v is reached.

The 48v battery will also have a low voltage setting to prevent damage to the battery. This means once the voltage falls below a certain value [39v ?] it will cut out to save the battery.

The poster really needs a 48v charger.

(Also you should not Charge a 36v battery with a 48v charger. Don't even think about doing this.)

As an extra thought, there really should be a special thread at the start of this forum on 'e-bike safety' with a special mention for 'Li-Ion batteries'.

 

[bilabonic]

OK, sorry, it's a 48v battery, have you looked for a fuse on/in the charger?

No, there is only the main fuse on the UK plug and thats OK, i will open it later and see if there's a fuse on the PCB somewhere or on the output.

 

[chris_n]

The 36v charger is designed not to over-charge and so it should stop charging once 37v is reached.

Not true, a 36V battery charger will charge to 42V.
Maybe the BMS will not allow charging as the voltage supplied is too low.

 

[Ajax]

Hi All

I've been using my brothers 'cheapy' Chinese 48v(10/11Ah) bike for the last few months. Apart from having zero brakes and a rust bucket it's been fine !!!

I put it on charge last night and it was still still dead/flat ?

I do not have a Multimeter handy atm (all out on jobs) BUT i just tried a 36v charger (got a load of them from BMSBATTERY when i did a self build) and it showed RED led for power, then once i plugged it into the battery it showed GREEN led/fully charged (not another red LED as charging)....

This is the same for 48v Charger, shows GREEN/Fully Charged ?

It's Cyclocity branded/lockable battery..(Pics Attached/no key atm so could not access the contacts).

What is my CHEAPEST option to replace the battery ?

Cheapest option would be a new 48v Charger.

I was also thinking of changing the controller to 36v, but the battery's onboard bms would still act on the Battery's 'Cut off voltage' (39v - 36V)

 

[bilabonic]

Yea, i've ordered a new charger.

Just had to use my Kalkhoff Endeavour, nearly had a heart attack !

Think it will be going up for sale as i NEVER use it and t's a great bike...

Nice to have decent brakes as well, nearly went over the handlebars..lol

https://www.cyclotricity.com/uk/no-charge-green-light

Looks like there is also an input fuse in the battery/BMS as well that causes NO CHARGE state as i have, highly unlikely though....

Can seem to find a battery though ? Just in case it is faulty/dead..

 

[bilabonic]

Opened the charger and could smell the 'burn' straight away, plus the input 3.15 fast blow 20mm fuse is OK.

 

[bilabonic]

Had new charger, plugged in STILL just a Green LED...Replaced the charging plug (in case inner/outer was differing size). STILL Green LED.

Next step is top open the battery tomorrow and see if the input fuse has blown on BMS/INPUT side !!!

It's NOT looking good TBH...

Anyone repair these batteries or now of where to get a cheap replacement (48/11-12aH)..

Cyclocity are NOT replying to me ?

Thanks guys.

 

[soundwave]

https://bga-reworking.co.uk/product-category/all-products/e-bike-batteries/

they custom make packs or you can send in what you have to get fixed, they will even pick it up.