Boosted Rev - Custom Battery (12s) + Stormcore ESC + ReVOLT! Dashboard

Boosted Rev Upgrade - The 'Wev' update - but different (Stormcore 60+, ReVOLT! Dashboard)

If you have been reading my previous blogposts, you'll notice this is the third post in a series where I initially wanted to replace a dead battery on my boosted Rev. Here's a short recap:

• Although I am delighted in the build quality of the Boosted Rev, my battery died because of intensive use (which is to be expected after 500-800 charge cycles for any Li-ion battery)
• I tried to tear the battery down to replace the cells, only to have a locked and completely useless BMS. The cells however were new, so it would be a shame to throw those away
• Because the Boosted ESC requires an original working Boosted BMS, without my battery, the ESC will not boot up and my whole scooter is rendered useless

I am absolutely delighted about the build quality of the Boosted Rev, this thing is SOLID! (and looks good being so). Between buying a new scooter and replacing the insides of the Boosted I chose the latter.

The plan going forward is:

1. Making a custom battery (using a generic BMS). The battery will be a 12S3P configuration (same as original Boosted battery, making it a 43.2V battery)
2. Using a Stormcore 60 to replace the Boosted ESC
3. Making a custom dashboard circuit board to re-use the existing dashboard unit (now the ReVOLT! Dashboard)

This is very close to the popular 'Wev' update some people know about. However, I'm choosing to do a couple of things differently:

• I'm using the same battery series (12S) as the original Boosted Rev battery. This is because I'm using a Stormcore 60 (which supports a max. configuration of 12 series cells) and because the motors of the Boosted are not rated to be used with a higher voltage. This would probably work however, but using a higher voltage/current on motors will induce more strain on them. Since I don't have official specs, I don't want to use a higher rating and possible destroy the motors prematurely. 
• I'm using a Stormcore 60 (instead of 100). This is because I don't need a higher current rating than 50A. The motors are rated each for a max. current of 35A and my battery can theoretically provide 50A of current, so a Stormcore 60 is sufficient.
• I'm creating a custom Dashboard, re-using the existing dashboard. I love the slick design of the dashboard of the Boosted Rev, so I decided to replace the circuit board, but keep the housing and casings.
• I'm creating 3D printable parts for the battery and Stormcore casings, making it waterproof

I'm also integrating a number of custom features:

• CAN-bus integration io UART communication. This is way more robust than serial communication and a standard in vehicle manufacturing.
• RFID keyless start mechanism. Scooter is locked on startup and requires an RFID tag (or your smartphone equipped with NFC) to start.

Possible future updates:

• GPS integration based on NEO module
• Custom BMS with SoC, cell balancing data and Smart charging (through the use of the CAN bus)
• Custom mobile app with Bluetooth integration (even though the Stormcore already offers bluetooth integration)

The Battery

This was a fairy easy part. I used the original battery holders and created a 3D printable case for the battery. I'm using a 12S3P configuration. This would provide the same range as the original Boosted Rev battery. 

To extend the range: Keep 12 cells in series but add extra cells in parallel. I have seen some people use up to 10 cells in parallel; Valid configurations are 12S3P, 12S4P, 12S5P, ....

It is vital to have max. 12 cells in series. Don't go above 43.2V!

The new cells in the original holders fitted inside the new 3D printed case

For the BMS, I chose a very generic 13S BMS from Amazon (there are plenty of BMS like that available online). Although this qualifies as cheap-ass Chinese, it works. I chose a 13S BMS because they are more available than the 12S BMS. Just wire up the 12th and 13th cell + wires to the same cell (the 12th).

I plan (and am already designing) to make a custom BMS board, making it thinner to fit inside the Boosted Rev scooter, but also implementing a couple of features such as transmitting the state of charge (using TI's new patented impedance tech.) via the CAN bus.

For now I fitted the cells and the small BMS inside the casing, wiring up the + and the - correctly. Be careful as you will have a live 43.2V on the connector output. Charging the battery can be done by wiring the original charger + and - respectively to the + and - of the battery connector.

Be careful when first charging the battery. It is good practice to never leave your battery to charge unattended and upon first charge, wire up an ampmeter to the battery. You should see the current drop down once the battery reaches it's rated voltage (which is 50.4V in my case).

I cannot stress enough to leave it to a professional to build a battery if you don't know what you are doing! Li-ion cells are extremely dangerous if handled incorrectly and can cause serious injury!

The ESC (Stormcore 60)

The 3D printable case for the Stormcore ESC

I chose to buy a Stormcore because the La Croix brand has a brilliant reputation and the Stormcore is rated one of the best ESC's out there. Additionally it's a VESC, meaning the firmware and hardware is open source and there is brilliant community out there to help out with a ton of customisable settings.

The Stormcore 60 is the one I'll be using, since the voltage and current rating is sufficient for my use case.

First, I disassembled the original Boosted ESC, which is fairly easy considering you're allowed to cut cable at the ESC's end (believe me, it's easier then to try to remove the cables from the ESC, since everything is glued in place).

We'll not be using the original ESC anymore.

I designed a 3D printable case that can be used to fit the cables and the Stormcore inside. If you print it in (for example) PETG, the casing should be waterproof. You can also just fit the Stormcore inside the scooter without casing, but be mindful that it's possible that the Stormcore will get dirty and that you shouldn't ride your scooter in the rain.

You'll need a couple of connectors to wire up the motors and cable to the ESC:

• 6x 4mm male bullet connectors. These have to be soldered in place on the motors cable.
• 2x 6 pin JST PH female connectors. (These are NOT standard JST XH connectors!!)
• 1x 8 pin JST PH female connector
• 1x 4 pin JST PH female connector
• JST PH crimping terminals

I don't know why the Lacroix team chose to use PH connectors (2 mm pitch), instead of XH connectors (2.54 mm pitch, more readily available). The PH connectors are difficult to find here in the EU. I ended up buying them on tme.eu). Alternatively, digikey, Mouser and LCSC also provide these connectors.

To crimp these terminals, refer to the Engineers Precision Crimping PA-09 Pliers.

If you printed the case, fit the cable inside, if not just proceed to the next step and strip the cables at the end. You should fit 5 cables:

• 2 motor cables (containing 3 power wires and 6 signal wires)
• Charger cable (simple + and -)
• Data cable to dashboard (5 wires)
• Battery cable (2 power wires and 4 data wires)

The motor  cables, 5 pin data cable, charger cable and battery cable fitted inside the casing

Strip the motor wires and solder 6 4mm bullet connectors onto the phase wires. Add JST PH crimping terminals to the signal wires and fit them inside the 6 pin female housing like so:

Wires coming in the 3D printed casing, next to the custom battery

Once the bullet connectors and crimping terminals are in place, the connections made are actually fairly easy.

You need to connect the three phase wires coming from the motor cables to the respective 3 phase wires on the Stormcore. Order does not matter.

The small data cables in the motor should be fitted in a PH-6 connector. Order does matter! (see picture) Check the datasheet of your ESC for correct connections.

The ReVOLT! dashboard is connected through 5 wires to the VESC:

• +5V
• GND
• CAN H
• CAN L
• ADC 1

An additional wire is the positive terminal of the rear lights.

For more information about wiring the dashboard, please refer to the user manual: https://michael-castiau.blogspot.com/2021/08/user-manual-boosted-revolt-dashboard.html

Once wired up, I turned the Stormcore on and was able to connect it to my computer.

VESC Settings

In order to make it more easy for you to setup your Stormcore to use in your scooter, I attached screenshots of the different settings I used. The settings are so, that ride experience is the same as the original Boosted scooter. You may tweak the settings accordingly to your own taste (within the limits of the hardware)

The most important settings are the motor current settings. The motor max/min and battery max/min current settings will be responsible for the majority of the ride experience.

Additional app settings are required for the dashboard to work. Again, please refer to the user manual article of the dashboard.

There is now also a tool that may set the necessary settings for the dashboard automatically. Please refer to: https://michael-castiau.blogspot.com/2021/10/boosted-revolt-software-tool.html

The settings listed here are for a 12S3P battery configuration. Don't use these for any 2P or 1P configuration! -12Amps regenerative braking is the absolute max allowed, don't go over this! (For a 3P battery configuration)

(As a matter of fact, I found out that, in order to create the typical ride experience, Boosted actually pushes the Li-ion cells to their limit when it comes to current draw when ramping and regenerative braking. This is not good for your battery. It may explain why so many batteries go dead. A 4P or 5P configuration with the same settings will be gentler on the battery cells.)

You may of course choose to tweak other settings but these are the most important ones. The throttle makes use of the ADC, which you may also change the curves of, but this won't have a very large impact, as long as you don't choose eccentric values.

Your maximum speed may be set by setting max. motor ERPM. I set mine to about 30 km/h which is about 18700 ERP. The faster you go, the less range. Be aware that some countries also have strict speed limitations on scooters. Also, the hardware of a Rev is not built to go at 70 km/h.... just saying.

The First Test Rides

Time for test rides! Be safe! For real, test your scooter first on a chair, wheels in the air. Test and re-test it for reliability. You don't want to find out some settings need to be tweaked by hurting yourself.

After some digging into the settings (which I shared here), I got amazing results on my first drives! The scooter feels sturdy, the 3D printed cases hold everything very tightly in place, there's no rattling of any kind.

The scooter picks up speed nicely and also has a nice regenerative brake. I couldn't be more happier about the result of this build so far.

I drilled a 16mm hole in the 3D printed part for the Stormcore VESC button (not all VESCs come with a button, so this step may not be necessary)