Controller help needed.

Neil5403

Pedelecer
Feb 5, 2017
213
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Staffs, England ST15
The two thin White wires next to the Yellow/C-, are they for temp sensor or switch ?
I should think they go to the on/off switch as they disappear under the cells at the opposite end. I haven’t removed it completely out of its case.
 

Nealh

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Aug 7, 2014
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Try the low reading voltage reading on that discharge solder joint but this time with the battery switch on.
 

Neil5403

Pedelecer
Feb 5, 2017
213
16
Staffs, England ST15
Try the low reading voltage reading on that discharge solder joint but this time with the battery switch on.
Just checked and the 2 white wires do go to the on/off switch.
The low reading of 51v to the low left solder is with switch on. 0v with switch off. Other 2 reading stay the same at high 53v with switch on or off
 

Neil5403

Pedelecer
Feb 5, 2017
213
16
Staffs, England ST15
Just checked and the 2 white wires do go to the on/off switch.
The low reading of 51v to the low left solder is with switch on. 0v with switch off. Other 2 reading stay the same at high 53v with switch on or off
I have just connected the battery back to the bike and connected the live from the battery base to the controller live input but used the ground from the soldered connector on the right side of BMS, which I think is the ground from all cells to the BMS and all works on the bike
So the fault is the ground output from the BMS.
I assume I need a new BMS (if available) or someone who knows what they are doing to tinker with this one.....
 

vfr400

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Jun 12, 2011
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Don't leave it like that for too long because you've bi-passed all the safety controls. As your battery is well-balanced, you should be OK for a few charges as long as you don't over-discharge it.

It seems that you're losing something through the output mosfets, so probably easier to replace the BMS.
 

Neil5403

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Feb 5, 2017
213
16
Staffs, England ST15
Don't leave it like that for too long because you've bi-passed all the safety controls. As your battery is well-balanced, you should be OK for a few charges as long as you don't over-discharge it.

It seems that you're losing something through the output mosfets, so probably easier to replace the BMS.
I am not going to use it like this , it was just a test to verify all was working inc controller and display.
Any idea where I could get this type of BMS from? Done a search but nothing as yet..
 

vfr400

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In principle, you can use any 13s BMS that can supply the current that your present one does or more. They have different connector arrangements. You have to make sure that your B1, B2, B3... wires go to the right positions. In the worst case, you have to cut off the connector from the cel-pack and solder all the wires to the new connector in the correct sequence.

Another problem is that your present one has a switch and BMSs with the switch connection point are not very common, so take a bit of hunting. you can normally find them on Aliexpress or Amazon and Ebay.

This one looks interesting if you don't mind soldering all the sense wires:

How many amps do you need?
 

Neil5403

Pedelecer
Feb 5, 2017
213
16
Staffs, England ST15
In principle, you can use any 13s BMS that can supply the current that your present one does or more. They have different connector arrangements. You have to make sure that your B1, B2, B3... wires go to the right positions. In the worst case, you have to cut off the connector from the cel-pack and solder all the wires to the new connector in the correct sequence.

Another problem is that your present one has a switch and BMSs with the switch connection point are not very common, so take a bit of hunting. you can normally find them on Aliexpress or Amazon and Ebay.

This one looks interesting if you don't mind soldering all the sense wires:

How many amps do you need?
My battery is 48v 14.5amp. Does it matter that the one above is 35amp?
What are the chances of the sense wire connector from my battery fitting this one? If you were to ignore the big blue surround and just fit the sense connector from by battery to it!
 

vfr400

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Jun 12, 2011
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My battery is 48v 14.5amp. Does it matter that the one above is 35amp?
What are the chances of the sense wire connector from my battery fitting this one? If you were to ignore the big blue surround and just fit the sense connector from by battery to it!
You're getting confused between amps and amp-hours. They're completely different things. The current is regulated by the controller. What's the maximum current written on it?
 
Last edited:

Neil5403

Pedelecer
Feb 5, 2017
213
16
Staffs, England ST15
You need a BMS that can provide say 20A or more, so the 35A one will be finefrom that point of view.

If you do a bit of searching, you might find one with the right connector.
I have found this from PSWPower, where I sourced the original battery from. Hopefully a straight swap. Ordered from China so a couple of week wait!
 

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