Pint Fender Battery (PFB)

Disclaimer: This WILL void your warranty. Attempt at your own risk. I am not responsible for any damages as a result of attempting this project.

This is my first attempt at making an extended range battery pack for the Pint. This is a project I am actively working on improving and will update this page as I make improvements. I will refer to this battery module itself as the PFB, Pint Fender Battery, from here on out.

UPDATE: Link to video of how to install everything.

Designed to not need a spot welder.
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How to operate VNR (Vampire and Ride) systems without errors:

Charging: While Pint and PFB are both turned off. Plug in charger. Turn on PFB. Once fully charged. Turn off PFB. Unplug charger.

Riding: While pint and PFB are both turned off. Power on Pint. Turn on PFB. Enjoy. When your done turn off PFB. Turn off Pint.

Note: Not following these instructions will NOT damage your Pint as far as I have seen, however error 16 will appear on the app, your board will not turn off by pressing the power button, and it will tell you to power cycle your Pint. You will not be able power cycle your pint without first switching off the PFB.

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I’d be happy to build one for you please contact me directly for details.

Thank you for reading and supporting this project!
If you read through this and think this is impossible to do yourself message me directly for assistance.

All feedback is welcome!

FAQ
Q: Is there a BMS?
A: No, this was just intended as a proof of concept and I was able to monitor the cells closely with a volt meter. I used bottom balancing and a fuse as my balance/protection strategy. Future versions/any that I build for a customer will have one.It is highly recommended to include one in your build.

Q: How much extra range?
A: More than double with 3500mah SANYO cells

Q: How long does this take to make?
A: Hard to say it took me about 24 hours the first time because I made mistakes but I think I could make another in less than 8 hours. I will update once I finish the second version.

Here is everything you need for this project. I will start with listing the materials and parts and then the tools and consumables.

Materials and parts:
(Quantity) Part Description Link
(5) 3x18650 Cell Holders https://amzn.to/2Nb8GTR
(25ft+) 18awg Wire Black https://amzn.to/2QQ8uKs
(25ft+) 18awg Wire Red https://amzn.to/35nmGQx
(2 pair) XT60 Connectors https://amzn.to/39FnnrK
(15) 18650 SANYO 3500mah cells (Ebay)
(2m) 135mm width Black Heatshrink https://amzn.to/2rorA1l
(1) Neoprene Foam https://amzn.to/2QOU2lQ
(1) Adhesive Backed Velcro https://amzn.to/33rS93X
(2) 18" to 24” Velcro Straps https://amzn.to/2WULAnK
(4) Hooks (3D print or buy metal) https://amzn.to/2ZOUHYG
(1) 10A Switch https://amzn.to/2sEx0X8
(1) 10A fuse https://amzn.to/2QpxSb0

Contact me if you would like to purchase a kit with almost everything you need and nothing extra. For example there is no need for an entire roll of velcro when I can just cut you off the two pieces you need etc.

Tools and consumables:
5-Point Pentalobe Security Bit TS20 https://amzn.to/2sQqc8P
T30 (3/8" drive required), T20, and T9 torx bits https://amzn.to/2QrTwvu
3/8" Socket Wrench https://amzn.to/39BNTCp
Solder Iron https://amzn.to/39GRQ8U
Solder https://amzn.to/2ty5ivi
Wire Stripper https://amzn.to/2FqZqX3
Flux Pen https://amzn.to/2SSiqpr
Helping Hands https://amzn.to/2MV0RkU
Scissors https://amzn.to/39DN5Nh
Voltmeter https://amzn.to/35na0Jl
Wire Bending Pliers https://amzn.to/2QpzGRf
Heat Shrink Variety https://amzn.to/2MXsaLg
Heat Gun https://amzn.to/2WS4ls8
Hot Glue Gun https://amzn.to/37yLSF6
Zip Tie https://amzn.to/2SU8RGK
Electric Tape https://amzn.to/2sMD1AX
Blue Locktite Thread Locker https://amzn.to/2sQVc8w
Black RTV Silicone https://amzn.to/2QUz19o

Disclaimer: LedoBuilds may earn an affiliate commission when you buy through the links above.

PLEASE NOTE: All photos will show 2x22awg stranded wires for both the black and red wires this is not recommended it is simply what I had on hand. I am waiting to get my solid core 18awg black and red wire to update. It is much easy to make with 1x18awg solid core wire for both the red and black wires. Solid core is slightly smaller than stranded since there is no air gaps.

Option 1: Solder to the pins on the bottom of the cell holders. (Recommended)

Option 2: Remove the contacts from the cell holders by pressing in the locking pin and pushing the contact pin down onto a hard surface simultaneously. Then solder the wires to the contacts such that you can still push them back in when your done. This proved to be difficult to do and take a bunch of time to complete.

Start at one corner and add the Main Pos wire then snake through adding the connections until you reach the opposite corner where you add the Neg Wire.

Add the 10A Fuse to the Neg Wire then hot glue to the cell holders.

Cut Pos and Neg Wires to Length

About 4in long from where they exit the PFB at the corner of the cell holders to there ends

About 1.75in from the PFB add the on/off switch to the negative wire.

Add Xt60 Connector to the ends paying close attention to polarity.

Discharge all cells to same voltage.

Install cells in series config into cell holder negative to positive. Check that the voltage increases each time you add a cell.

Final voltage at the xt60 should be 40V to 63V.

Double Check Voltages and Polarity.

Add BMS at this point if you like.

I will add more details once I receive my BMS.

This is a new process I completed on a 4S pack as a test and it turned out so good I am including it here.

Simply cut the foam into a long strip the width of the cell holders and wrap all the way around long ways.

Then cut out strips to cover the ends.

Don't trim until after you heatshrink it.
Leave about 3-5in past the ends of the battery.
Heat the ends first to prevent crinkling.

Trim edges then heat again.

Cut 1-2" strips and place on fender and PFB so they line up.

Offset them ever so slightly as shown in the photos to make install easy.

PLEASE NOTE: All photos will show 2x22awg stranded wires for both the black and red wires this is not recommended it is simply what I had on hand. I am waiting to get my solid core 18awg black and red wire to update. It is much easy to make with 1x18awg solid core wire for both the red and black wires. Solid core is slightly smaller than stranded since there is no air gaps.

The internal wiring of the Pint is reverse of what is printed on the XT60 connector. Which is why red positive is going on the negative side of the XT60 and vice versa. (Check with a voltmeter)

I also added conformal coating and some electrical tape to cover the exposed metal.

The following note is purely optional:

Add small banana plugs to the leads so that if made and given to someone else they can pass the wires through the grommet without the need to solder the final XT60 connector.

DO NOT RECOMMEND using a tiny screwdriver bit to get the wheel axle bolts off. Get a 3/8” drive T30 torx head and use a 3/8” socket wrench to get them off and on. I broke my screwdriver bit.

PLEASE NOTE: All photos will show 2x22awg stranded wires for both the black and red wires this is not recommended it is simply what I had on hand. I am waiting to get my solid core 18awg black and red wire to update. It is much easy to make with 1x18awg solid core wire for both the red and black wires. Solid core is slightly smaller than stranded since there is no air gaps.

Remove the aluminum battery box plate.

Unscrew the 2 T9 screws holding down the Pint's BMS cover.

Sqeeze and pull off the short 16 Pin connector.

Unplug the XT60 going to the controller.

Plug in the Double ended XT60 you just made.

Plug in the Controller XT60.

Route the wires as neat as possible.

Bend the controller power wires about 10 times along the length with the wire bending pliers to shorten them a few inchs to get everything to fit.

Route the wires you added and the smaller wires under the charge port.

Route the controller power wires above the charge port.

You will need a big adjustable wrench.

Add a drop of Black RTV Silicone to the grommet to improve the water proof seal.

Add Locktite Threadlocker to bolts when you reassemble.

Cut wires to about 2-3in in length from the gromet so you can lay the xt60 flat on the rail.

And add the XT 60.

Double check polarity of PFB and pint are all going to match up correctly.

You can leave the PFB installed at all times if you like.

Thank you for reading and supporting this project!

If you read through this and think this is impossible to do yourself message me directly for assistance.

All feedback is welcome.