NiMh BMS temperature sensors burned

Carlos Oliveira 5 years ago updated by 4 years ago 32

Hello all.
I've been trying to contact Vectrix team for help with no success, so I decided to place my message public to see if someone can misleading some doubts I have.
My VECTRIX-VX1 has suffered a problem with the wire battery temperature sensors (both front and rear) which burned. This affected the CAN bus on the Controller board but I believe that I already solved this problem with some components I replaced.

I also noticed that the charger is not charging but according with my understanding, this might be due to the lack of temperature information, from the battery sensors to the charger and the charger itself might be ok, is that right?

In the meantime, I ordered a new wire battery temperature board and is my intention to replace the damaged wiring with the new one. However, my concern is that probably this new board needs to be programmed and I don’t have the means to do it (CANBus/USB converter). I sent an email to Vectrix team asking if it would be possible to pre-program this board (for NiMh batteries), before they send it to me but till now, they didn’t answer my question.

Those boards are sent "empty" and then will be programmed via CAN, right?
Does anybody knows if it can be pre-programmed, according with the firmware version referred by the buyer?
Is there any other way to program these boards, other than via CAN (for example, programming the PIC16F677 directly with a dump)? Thank you!

Kind regards,

Carlos Oliveira

I have the same problem.

Hi guys, in case the temp sensor boards (there is no BMS with the NiMH batteries) are shorted you may indeed have the 7805 5V power regulator IC damaged in the charger. In case you don't see 5 volts on the output it needs to be replaced obviously (can be checked on the 24 port interface as well). This floating 5V powers the temp boards. The new boards should come preprogrammed. I am not aware of a firmware for these neither a programming method via CAN bus with Scooter Diag.

There is ICSP on these boards for low level programming marked as J1. Should the above fail and you need the hex files I could try to extract them from my boards.

/ Azzuro


thanks, I just bought a vectrix VX-1 with the problem paying it as damaged. Now I would try to repair but I didn't received yet. I will inform the forum about the repairs.

Hello Tommaso and Azzuro.

Yes, I solved the problem buying the temp sensor frontal board and repairing the rear one with new components (PIC16F677, MCP2515, MCP2551, NTC-10K and a few more). I used the method referred by Azzuro, extracting (read) the hex file from the new frontal board and copying it to the new PIC16F677. This was done with a PicKit3 programmer, connected to the ICSP pins of the boards. The 5v regulator (7805) on the charger was also replaced because it was shorted.

Tommaso, if you decide to repair the boards, I can supply you the dump to program the PIC16F677, as Azzuro also offered, just let me know.

Good luck!

Hi Carlos, many thanks. Yes I would try to repair the boards. So the dump files will be highly appreciated.

I will receive the vx-1 in the next few days and I will check how many parts I need to change.

Ok Tommaso, as soon as you receive the scooter open the battery compartment and check for both front and rear temp sensor boards to see how damaged they are. Check also all the 12 sensors connected to the two battery's elements. You will need to disassemble the batteries to check all 12 sensors, these will most likely be burned as well.

Access also the charger and be ready to remove it. I will tell you later what are the pins on the 24 port interface to measure and check if the 5v regulator is shorted or not.

Do not hesitate to contact me.



Hi , I have the same problem,  I opened  my  batteries compartment  

2 days ago and all my temp sensors are burn and also the front and back temp sensor boards are damaged. Now i try to check each battery cell to charge and masure how is holding the charge. Please let me know what next I need to do . Thank you so much .

Thanks Carlos, I already received some pictures:

Oh Yes, it's very similar to the state of my boards.

You will need desoldering smd tools to remove those 3 burned chips (PIC16F677, MCP2515, MCP2551). There are two more devices on the board, that you need to check. It's a 10k NTC and also a 3 pin (SOT-23) device. This last, it's also a thermal sensor. I can send you pictures of both later, ok?!

I used your picture and marked on red the other two devices to check. See image below! 

thanks, can you tell me p/n, expecially for sot23 device?

Yes, I will!

Let me confirm the smd marked code, as soon as I arrive home and then I let you know the P/N for order.

I am glad you guys on the right track with this fix :) Especially with a blank PIC programmed up, nice one.

Tommaso, the P/N for the temperature sensor with 3 pins (sot-23) is: LM45CIM3.

If you decide to purchase it from FARNELL, as I did, the farnell code is this: 3009017.

Regarding the 12 sensors connected directly at the battery terminals (for those that are not burned), check the resistance value across the smd NTC device under the small drop of composite. It should indicate around 10 KOhm (at 25ºc). Make sure to desolder the wires first, to avoid the components from the board to affect the ohmic value. 

The burned sensors, probably need to be replaced. However, you can evaluate if the small pcb damaged can be repaired or not. If you try to repair it, make sure to remove all the burned pcb because coal will act as a resistor. 

Let me know if you need more help on this.



Hello Azzuro.

Yes, it worked out! At least until now the scooter behavior is normal. I was afraid the chips might have different programs to differentiate the information from each one of the batteries (frontal and rear) but that doesn't seems to be the case.



Good to know Carlos so single code for all boards. Hopefully other owners with some skills can use this method as well. / Azzuro

Hello Andrei.

The easiest and quicker solution is to purchase a new set of boards and sensors and just replace it. Be aware for the possibility of your charger has also been affected on the 5v regulator (7805). This is an internal device with 3 pins (TO-220) that usually get shorted, in situations like this and must be replaced.

If you have the skills and the tools to repair by yourself the damaged boards, you have to remove all burned components, buy new ones and program the PIC16F677. Please read the previous messages I sent to Tommaso for more specific details. You can save some money with this solution but be ready for a meticulous job!



Thank you so much Carlos!

Before  I want to check if all my batteries cell ( the original  one 2007) are good and replace the bad ones  and also  I need to know the reason  this two BMC  bords went bad and all my temp sensors . I will appreciate if you  can help me to investigate the cause to get burn all this BMC and temp sensor and what to expect  next to happen .



In my case, I believe the sensors from both boards, were damaged by watwer or moisture and this lead the thermistors wiring to make contact with some battery terminals. Of course the microcontroller was the first to be sacrificed and all adjacent components were also damaged. The 5v supply for this board comes from the charger (IC201 - 5v regulator - L7805) which output was pratically shorted.

So, in your case, after replacing all damaged components from both boards and sensors, make sure your charger was not affected on the 5v circuitry. You can make a quick check by measuring the resistance on the two connectors that plugs on the front and rear boards (scooter wiring). See the images attached for reference (top view). In my case this value was 18 ohms - too low, almost a short! The expected value shall be around 14 Kohm.

I hope this helps you!

Hello Carlos, Tomorrow I will receive my vectrix. please coul you send me  a link where I can download original firmware for sensor boards?


Hello Tommaso.

I wasn't able to find a place where I could download the file for the temperature sensor boards. For this reason, I had to purchase a new board (the frontal one) and read the hex file from the microcontroller chip (PIC16F677). I took a chance and copy it to the rear board. Until now, it seems to be working without problems!

I can send you the file I read from the frontal board, no problem!

Please note, I still don't know if the files are different, since there are a frontal board and a rear board. All I can say is that my scooter is running with the same file for both boards and the behavior is normal.

Let me know if you want the file.



Hi Carlos, out of curiosity are you sure it is exactly the same firmware for the front and rear Battery Monitors ? The reason for my question is they have different CAN addresses 4D and 4E.

Hi Andrei, I guess you would need to buy replacement boards from vectrixparts for the boards those are burned. In addition you can ship the damaged ones to us an we would try to fix them as part as our learning curve, no guarantees though due to the extensive damage. If successful you would have spare boards as well at the end.

/ Azzuro

Hello Azzuro.
No, I am not sure about the firmware be exactly the same for both boards. I decided to purchase just one board (the one that was in worst conditions) and read the hex file from it. Then, I copied this file for the board that was under repair (rear) and give it a try to see what would happen. I assume this test might not have worked correctly, however the truth is that the scooter already runned around 200 km and it seems be working good.
According with your message, you read both files separately and you found some different addresses, meaning the files actually must be different for some reason, right?



Hey Carlos,

 Yes based on the CAN address difference I would assume there are minor differences between the two images (unless the firmware detects the rear/front variant and changes the address accordingly for the MCP2515). I will check in a few weeks. On the CAN communication level the two boards are clearly differentiated.

/ Azzuro

Hello Azzuro.

I agree with you! I've also been checking the diagnostic software and it's really clear the evaluation of the temperature values for each battery module, distinguishing well the front and rear batteries.

For now, I will keep my scooter running the way it is and see what happens. In fact, untill now everything seems normal, as I said before. I will let you know if something abnormal happens. Meanwhile, if you find more information on this, please tell me. Thanks!



hello Carlos, thanks, I will try programming the same firmware on the boards. You can send it to my address: tommaso.delgrosso@gmail.com


Tommaso, check your email.

Good luck!

Hi Carlos

It seems I have the same problem as you have, burned front temperature sensor board. I intent to order one from Vectrix parts has I have no skills to repair mine. Can you please tell me, if I order a new front board will it come with temperature sensors ?

My scooter is stopped almost a year so the batteries where completely depleted, I have already charge it in groups, I have around 1.36/1.37 in each one of the 102 cells, it that a ok value?

all the cells seems to be in good shape but I really need to confirm the voltage range.

thanks in advance for all the help.



Ps. +351933396980

Call me Carlos if you have the time and will.