Author Topic: SOLVED: How to bridge the VCU (problems with battery B40 etc)  (Read 3371 times)

gyvermc

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SOLVED: How to bridge the VCU (problems with battery B40 etc)
« on: October 29, 2023, 01:53:14 PM »
As I understand from all the manuals, VCU is not really needed to drive the bike.
Mainly the VCU is whatching the charging and discharging, shows dash, checks key switch.
Lights are working without VCU if you just supply 12V to the system.
« Last Edit: November 19, 2023, 02:00:10 PM by gyvermc »

gyvermc

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Re: How to bridge the VCU (problems with battery B40 etc)
« Reply #1 on: October 29, 2023, 02:03:29 PM »
What I did so far:
1) unplug VCU (2x) and DC72/DC12V Converter
2) keyswitch on (necassary?)
3) supply 12V to the system and to the 72V main relais (see Enertia wiring diagram "Controller Keyswitch" PIN4)
-->  http://brammoforum.com/wiki/index.php/File:Enertia-Wiring-diagram.pdf
4) kickstand up (necassary?), Motor switch on: PCM controller powers up and shows constant green light

To get the wheel moving I tried at lower harness "Molex VCU Connector 03" (brown color):
A) supply 5V+ at PIN 1G and 5V GND at PIN 1B (for Throttle)
B) bridge Pin 1C and PIN 2C (Throttle Signal (Viper) IN and "MC Throttle Signal OUT")
C) PIN 2D (Speed1) and PIN 2F (FS1) -> bridge to 72V GND (see picture of DMC manual)
D) supply 5V+ at PIN 2G (for MotorController CONN 50 PIN16)

But the wheel is not turning.
What did I forget / do wrong?
« Last Edit: October 29, 2023, 02:29:50 PM by gyvermc »

gyvermc

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Re: SOLVED: How to bridge the VCU (problems with battery B40 etc)
« Reply #2 on: November 19, 2023, 02:23:46 PM »
Finally the wheel is spinning  8)

What you need to know is, that the Enertia wiring diagram (Wiki) was not accurate in my case.
So I recommend to measure all wires to confirm the connections first!

After a lots and lots of tests I found out how to go around the VCU, so the bike can run on batteries without BMS.

Now Im trying to get the certificate to allow the bike to ride on the road (legally) 8)

Also it can be done to drive backwards or how to activate the recuperation.

If you are interested, having me modifing your bike, just PM.
« Last Edit: November 19, 2023, 02:43:56 PM by gyvermc »

patrick

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Re: SOLVED: How to bridge the VCU (problems with battery B40 etc)
« Reply #3 on: November 25, 2023, 08:49:06 PM »
Well done

Marchik

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Re: SOLVED: How to bridge the VCU (problems with battery B40 etc)
« Reply #4 on: September 04, 2024, 04:24:50 AM »
Hi. Can you provide exact details? I got a brammo enertia bike where I have replaced with aftermarket batteries and wanted to get rid of the original bms and have the wheels spinning. Thanks for the advice.


Finally the wheel is spinning  8)

What you need to know is, that the Enertia wiring diagram (Wiki) was not accurate in my case.
So I recommend to measure all wires to confirm the connections first!

After a lots and lots of tests I found out how to go around the VCU, so the bike can run on batteries without BMS.

Now Im trying to get the certificate to allow the bike to ride on the road (legally) 8)

Also it can be done to drive backwards or how to activate the recuperation.

If you are interested, having me modifing your bike, just PM.