Page Last Modified On: October 28, 2021


The Baserunner is a compact field oriented motor controller (FOC) designed to fit inside the baseplate cavity of popular Hailong and Reention downtube battery packs. It has the same functionality and feature set of our popular Phaserunner motor controller, but in a smaller / flatter profile. This makes it ideal for ebike systems that can benefit from the discreteness of a controller hidden inside the battery mount.

 Baserunner Installed in Downtube Battery

Unlike the Phaserunner which works with up to 72V nominal batteries, the Baserunner has a maximum upper voltage 60V which restricts it to 52V nominal batteries or lower, and it has correspondingly lower current limits due to the smaller size. We have two models in production. The baserunner_Z9 model uses standard mosfets with the Z910 motor plug and has a maximum peak phase current of 55A, making it perfect for small 250-500 watt nominal hub motors. The slightly longer L10 model uses performance mosfets and can support 80A peak phase currents, making it an ideal option for medium to high power motors.

  Baserunner_Z9 Baserunner_L10 Phaserunner
Max Voltage 60 V 60 V 90 V
Max Phase Amps 55 A 80 A 96 A
Continuous Phase Amps 30-35A 45-50A 50-55A
Motor Connector Type Z910 L1019 MT60 or L1019


  • Slim Profile fits in popular battery cradles, or mounts discretely with other mount
  • New in V4 Model, all Waterproof plugs for CA3, PAS Sensor, and OEM Cables
  • Ability to decode  Combined Speed / Temperature signals in motor cable
  • Proportional Regen available through throttle signal or stand alone wire
  • Works both Sensored and Sensorless, and even with very high eRPMs
  • Waterproof, 100% potted electronics
  • Fully Programmable parameters (regen voltage, max phase and battery currents etc.)
  • Field Weakening allows you to run motors faster than normal back-emf limit
  • Embedded LED with comprehensive flash codes for troubleshooting
  • Virtual Electronic Freewheeling for removing drag of regen capable hub motors
  • Broad Operating Voltage range from 20V to 60V (14S Li-Ion, 24s LiFe)
  • Automatic Thermal Rollback prevents mosfet damage from controller overheating

Baserunner Connector Standards

Here is the plug standard for our Version 4 Baserunner devices

14 AWG Silicone Noodle Wire for Battery Leads


The controller itself has a short pair of + and – power leads which would be terminated to match the plugs on the battery pack. Depending on your battery these may be flat spade connectors with 4 or 5 contacts, or round bullet terminals for power and small round pins for signals. Reention downtube batteries usually use a flat 4-pin terminal, while quite a number of plug types exist for the Hailong casings. If the baserunner is purchased with a battery pack we will install the mating terminals, while if it is purchased by itself then the user would be expected to solder the wire to the terminal already present in their existing battery cradle. 



The motor cable is 38 cm long and is terminated with either the Z910 HiGo style 9 pin waterproof plug or the L1019 10 pin plug. These connectors include the 3 phase wires, 5 hall wires, and one or two additional signal wires for temperature and wheel speed signals the CA3. The cable length is sufficient to reach from the downtube battery mount to the rear hub motor on most bicycle frames, but for front hub motors or extra long frames we have both 60cm and 90cm extension cables available too.

6 Pin HiGo Plug for PAS / Torque Sensors

6 Pin PAS / Torque (New!, V4 Units Only)

A 6 Pin HiGo Mini-B or equivalent waterproof plug allows for direct hookup of a PAS or Torque sensor to the motor controller. The pin standard is compatible with the ERider torque sensors, and uses 12V rather than 5V for the power supply. This cable is not used or required when PAS or torque assist is handle via a Cycle Analyst, but it will provides a future option for using the native PAS feature of the controller without a CA device attached.

CA3-WP Plug

8 Pin Cycle Analyst (WP8)

The Baserunner is supplied with the waterproof 8 pin HiGo plug (WP8) for running the device under the control of a V3 Cycle Analyst. If the application requires connection to an older CA-DP plug, a WP8->JST adapter should be purchased here.

V4 Baserunner Main Plug

9 Pin Mains Cable (New! V4 Units Only) 

The V4 Baserunners also feature a 9 pin waterproof plug that brings out the cables commonly used in ebike wiring topologies with a main signal harness that splits out at the handlebar into throttle, ebrake, display, and light connectors. This harness is available to our OEM business customers and is not something we currently offer at the retail level. 

Short Cable from Main Plug provide DC Power for Rear Lights

DC Power Tap (New! V4 Units Only) 

For our customers using this controller with a V3 Cycle Analyst, we also include by default a short power adapter from the Main plug to a 2 pin HiGo plug. This adapter not only gives a convenient power source for a rear bike light, it also shorts the regen and throttle signals together so that the CA3 can have full control over regenerative braking features .

TRRS Communication Port


The back of the Baserunner includes a TRRS jack for connecting the Baserunner controller to a computer or USB-OTG capable smartphone using USB->TTL serial cable. This is the same cable used with the Cycle Analyst and Satiator charger, so if you already have it then great there is no need to purchase a 2nd one. When not in use, the there is a small rubber plug included to seal this hole.



On the V3 Baserunners, the battery and motor cables are identical, but the signal plugs differ. Instead of PAS and Mains connectors it has a single 3 pin JST throttle plug for direct throttle hookup:

3 Pin Throttle (V3 and Earlier Only)

The throttle connection on these devices uses the 3-pin JST-SM plug standard allowing you to have a simple throttle controlled system. Under the heathshrink of the throttle plug is a pair of white and yellow wires that can be hooked up to a remote on/off switch. It's possible to separate the blue and green signal wires of the throttle connector if a separate ebrake input is also desired. There is also a forwards/reverse wire that can be optionally wired by you so it may be shorted to ground to enable reverse functionality.


Version History

The baserunner has seen 4 significant design changes since its first introduction.

V1 Device: The original Baserunner was released in 2017 and was only available with the Z910 connector standard. This model used a 6 pin JST Cycle Analyst plug with the on/off power switch tucked in the throttle heatshrink. Default power state was ON. 

V2 Devices:The V2 Baserunners were rolled out in 2019. These units swapped out the 6 pin CA-DP plug for the waterproof 8pin CA-WP connector, which enabled the on/off system power to be controlled by a handlebar switch off the Cycle Analyst, and also provided an option for motor temperature sensing through the CA plug. By default the power switch was OFF. This V2 release included both the Z9 model and also the higher power L10 version.

V3 Device: The V3 update took place in 2020 and had the exact same connector standard as the V2 model, but featured an internal demux circuit to support combined temperature and speed signals in the Z910 motor plug. This demux circuit is backwards compatible and fully supports motors that use the white wire as just a speed sensor or just a temperature sensor too.

V4 Devices: Finally in late 2021 we released the V4 Baserunners with a substantial overhaul. The V4 units continue with the 8 pin CA-WP plug but also have a 9 pin Main signal plug to provide optional support for conventional ebike displays. The independent 3 pin JST throttle plug has been removed, and replaced instead with a 6 pin HiGo connector that can be used for direct hookup of a throttle, a PAS sensor, or a Torque sensor, even without a CA3 device in the system.

Stand Alone Model

Stand Alone Baserunner, Long Battery Lead on Same EndWe have also been producing a slight variant of the Baserunner_Z9 controllers that has a 90cm battery cable emerging from the same end of the controller as all the signal cables. This model was developed specifically for our Brompton Bike conversion kits for a nicer cable routing, and can be suitable for other applications where the controller is mounted externally without a downtube battery. 



If you purchase the Baserunner from Grin Tech along with one of our downtube battery packs, then it will come pre-installed inside the battery cradle. No installation is required. If you are purchasing the baserunner to add to an existing battery, then the stock aluminum heatsink that came with the battery cradle needs to be removed and replaced with the baserunner assembly. We have cradles available for Hailong and Reention casings, the two most popular producers of downtube battery enclosures. You remove the connector pins from the original plate and move those over to the baserunner, soldering the + and - wires appropriately.

Difference between Hailong and Reention Baseplates

On the larger Hailong-03 cases, you will also need to drill a hole in the back of the plastic base in order to access the TRRS programming port.

You can also use the Baserunner controller without a downtube battery pack if the form factor is appealing for your application. We provide 3 alternative mounts too

Baserunner Tube Mount

A universal tube mount that makes it possible to zip-tie the baserunner to any round bicycle tubing

Baserunner Fork Mount A flat plate mount with a bend and hole in it to attach to the brompton bicycle fork
Baserunner Flange Mount A flat flange mount with screws on either end for bolting the baserunner to a flat surface, used in our Wheelbarrow kits



The Baserunner controller uses the same Phaserunner software suite available for Windows, MacOS, Linux, and Android devices. Note that V4 Baserunner devices require the 1.5 or later software release. The 1.4 and earlier software will produce an unrecognized device error. 

Phaserunner Suite, Windows, Portable

Phaserunner Suite, Windows, Installer

Phaserunner Suite, macOS (Requires macOS 10.12 or newer)

Phaserunner Suite, Linux

There is also a version for Android that is in development, and available for beta testers on the Google Play Store. This requires the use of a USB OTG compatible device, as well as a USB OTG adapter to connect our USB->TTL programming cable to the micro USB or USB-C connector present on most smartphones.  

The drivers for the FTDI chipset inside the USB-TTL adapter can be found through FTDI here - https://www.ftdichip.com/Drivers/VCP.htm


User Manuals

The user manual for our V4 Baserunners is available here

We did not produce a separate manual for the V3 and earlier devices, but the setup, tuning, and wiring details on those were very similar to our Phaserunner motor controllers and the manual for that can be used as a reference.



CAD Drawings

Where to Purchase

The Baserunner controllers can be purchased from Grin directly by themselves, or as part of a full ready-to-roll kit system.