Cuts out under load, 52v battery shows 57v fully charged.

Paulpmpmpm

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Oct 10, 2020
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When I accelerate with wheels on ground , instant cut out. I have to plug charger back in to allow me to turn back on.

If I accelerate with wheels off ground, motor spin.

52v battery fully charged showing 57v.

Any help please?

Edit: even with wheels off ground it still cuts out instantly when accelerating.

Edit2: with charger plugged in wheels spin while off ground.
 
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vfr400

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Jun 12, 2011
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Sounds like your controller amps is greater than what the battery can give. You have to tell us which controller and which battery you have.
 

Paulpmpmpm

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Oct 10, 2020
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Sounds like your controller amps is greater than what the battery can give. You have to tell us which controller and which battery you have.
Thanks, battery is 52v 23.4ah , 1216.8wh battery from China.

I have 2 controllers 1 for each 1000w motor. Controllers are JP25Ah 52v dual controllers.

I managed to do around 200kmh before facing this problem. I am about to cut open battery and test cells.
 

vfr400

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Thanks, battery is 52v 23.4ah , 1216.8wh battery from China.

I have 2 controllers 1 for each 1000w motor. Controllers are JP25Ah 52v dual controllers.

I managed to do around 200kmh before facing this problem. I am about to cut open battery and test cells.
You're taking 50 amps out of that battery! It doesn't sound good if it's a no name unbranded cells one. Please show a link to it. Volts and Ah doesn't mean anything. We need a specification.
 

peter.c

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Apr 24, 2018
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thurrock essex
Can you try just one motor at a time? this will reduce the demand on the battery
What bms is fitted in the battery and what type make are the cells
 

Paulpmpmpm

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Oct 10, 2020
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You're taking 50 amps out of that battery! It doesn't sound good if it's a no name unbranded cells one. Please show a link to it. Volts and Ah doesn't mean anything. We need a specification.
Hi I have attached pic of battery pack I can't find a link to one online.

I just cut it open and there is 7 packs of cells. Each tested between 4.11 and 4.18 volts.

Edit: each individual battery has this writing on : SINC ISR 1865026 A19829537
 

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Paulpmpmpm

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Oct 10, 2020
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Can you try just one motor at a time? this will reduce the demand on the battery
What bms is fitted in the battery and what type make are the cells
Hi I have attached pic of battery pack I can't find a link to one online.

I just cut it open and there is 7 packs of cells. Each tested between 4.11 and 4.18 volts.

I tried with one Motor and got the same result.
 

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peter.c

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Apr 24, 2018
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thurrock essex
If the sticker is correct it should be 9 cells in parallel and 14 in series total 126 cells
Only 7 cells will lower the total capacity and only 98 cells can you show a pic of the battery pcb
suspect the battery or the bms is cooked, can you do a voltage check under load
 

Paulpmpmpm

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Oct 10, 2020
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If the sticker is correct it should be 9 cells in parallel and 14 in series total 126 cells
Only 7 cells will lower the total capacity and only 98 cells can you show a pic of the battery pcb
suspect the battery or the bms is cooked, can you do a voltage check under load
Hi mate there seems to be 18 cells in parallel total 126 cells. I have attached a pic.

When I accelerate under load it drops to 0 volts. Even when not under load it cuts out also. It only doesn't cut out if I have charger plugged in.

I hope this info helps and pictures, sorry if I'm not helping very well I will try supply as much info as I can .
 

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peter.c

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Apr 24, 2018
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thurrock essex
The volts drop to zero ? then the bms cannot cope with the load and is cutting out/or overloaded and has damaged or another possibility is a joint/ weld is going open circuit in the pack
To much current required for battery battery pack to supply one 1000w motor would stress it two have probably killed it ,others on here might be able to suggest a way around it but suspect its a battery rebuild or replacement
 

Paulpmpmpm

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Oct 10, 2020
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The volts drop to zero ? then the bms cannot cope with the load and is cutting out/or overloaded and has damaged or another possibility is a joint/ weld is going open circuit in the pack
To much current required for battery battery pack to supply one 1000w motor would stress it two have probably killed it ,others on here might be able to suggest a way around it but suspect its a battery rebuild or replacement
Okay mate thanks so probably the BMS needs replacing then.

It's actually a scooter not a bike, it has front and back motor 1000w each. It was sold like this from factory IV only done 200km I thought it would be able to handle it.
 

vfr400

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Jun 12, 2011
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Its a 9s14P battery, so you've only measured half of the cells. we need a listing to comment further. Can you disconnect one controller and try it with just one motor to see if it's too much current that's causing the cut-outs?
 

peter.c

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Apr 24, 2018
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Did the motors ever get hot, is it two controllers on one throttle, any water damage to the battery pack
are the wires damaged as they go into the wheel s
 

Paulpmpmpm

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Oct 10, 2020
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Its a 9s14P battery, so you've only measured half of the cells. we need a listing to comment further. Can you disconnect one controller and try it with just one motor to see if it's too much current that's causing the cut-outs?
Sorry I'm new to this it looks like there 7 sets of 18 battery's? I have checked the voltages on the BMS and they are all 4.1.

Yes I will try again tomorrow and reply back, thank you.
 

Paulpmpmpm

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Oct 10, 2020
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Did the motors ever get hot, is it two controllers on one throttle, any water damage to the battery pack
are the wires damaged as they go into the wheel s
Yes motors have got hot before.

Yes 2 controllers one throttle.

I have ridden scooter In the rain but not sure of water damage. I did try to seal off everything with sealant.

I'll have a look tomorrow when I go into garage but they could be. You think it could be motors ?
 

vfr400

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Jun 12, 2011
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Sorry I'm new to this it looks like there 7 sets of 18 battery's? I have checked the voltages on the BMS and they are all 4.1.

Yes I will try again tomorrow and reply back, thank you.
Each 3.7v cell group has 9 batteries in parallel. 14 of those make 51.8 volts

Fully charged, each cell group would be 4.2v. a4 x 4.2 = 58.8v. Your 57v is a bit low.
 

peter.c

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Apr 24, 2018
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Thats a mega fast charger 3 to 5 hours. Wow it must be like a rocket 70 kph every thing must be pushed to the limit
might get very hot controller s and even cook the battery
 

Paulpmpmpm

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Oct 10, 2020
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Thats a mega fast charger 3 to 5 hours. Wow it must be like a rocket 70 kph every thing must be pushed to the limit
might get very hot controller s and even cook the battery
I have actually already replaced one of the controllers.

I think the battery is okay. I have tested using this method
and they all came back as 4.1v. Does this mean BMS and battery okay?

Maybe controllers ar broken.