Sur Ron 67V ASI 10kW Marathon Kit ASI BAC4000 Marathon 67v *65Ah

Original price was: £2,848.00.Current price is: £2,649.00. (price including VAT)

Sur Ron ASI 10Kw Marathon Kit ASI BAC4000 Controller + Marathon 67v *65Ah


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Sur Ron ASI 10Kw “Marathon” Aftermarket Kit

ASI BAC4000 Controller + Display + Marathon 67v *65Ah Battery + Charger

Loom, Display, Mounts, Fully Assembled and Programmed “Plug n Play”

Our latest and improved fully motor protected upgrade!!!

This is truly plug n play
All taxes and import duties paid and free UK shipping

5 power modes, power tuneable display


Sorry no EU or  International shipping

This kit is designed to give that little extra “oomph” to your standard bike but massively increase range. We do not consider this set up a hard core performance upgrade. More an upgrade for the discerning customer who wants to enhance and  improve upon the performance of the original bike with very little risk to motor damage or overheating. Being this is 67 18s battery (not 60v 16s), the higher volts and greatly improved field weakening give a much higher top speed over standard. Acceleration has a very noticeable improvement and will be enhanced with a sprocket change t0 around 56T or 58T (depending on your weight) very light riders can go  to 54T. This set up if for those that want almost maximum distance without the huge cost of  our high end 72v battery.


This controller can take battery swaps ranging from the standard untouched Sur Ron battery at power level 3, a fully bypassed battery at power level 4 (burst) and full 9.5 kw on power mode 5.

The controller now features a full working display showing: speed, power, battery charge, date and trip. Set with 5 power levels as default that can be flicked at the touch of a button on the fly (just your thumb, no gloves off or stopping). Can be used like a gearbox to slip up and down the power levels (5 levels set as our default) to suit your terrain and riding style. Our latest display can have each of the 5 power levels independently tuned by you to your power tastes (overall power can not be turned up without a one off free remote session).

The controller comes fully potted and with all leads and looms fitted and waterproofed. The mounts are in place, 3D printed with the addition of protective “Wings”.

Power levels:

5  Power levels on the fly at simple handlebar push of a button. From super echo to over 60MPH

Unleash more performance and range with correct gearing.  Higher gears (smaller rear sprocket) does not mean higher top speed. Over labouring the motor with the wrong gearing costs top speed, acceleration and range.

A fast efficient spinning electric motor goes better – simple!.

Controller Feature Set

  • FOC (Field Oriented Control)
  • Improved torque throughout the rev range.
  • Higher RPM compared to the stock controller.
  • Silky smooth throttle control and responsiveness, like a fine adjustable knob on a light switch.
  • Improved efficiency due to FOC algorithm, premium internal components within the controller (like the mosfets) which increases efficiency while reducing heat losses.
  • Loom
  • Mounting Kit
  • Install Instructions
  • Display


Others copy, we improve and change. The old APT display (as used by everyone else) had a tendency to steam up on a hot day if  the  bike had been washed with a hose or exposed to very heavy rain.  So guess what? We went to another display manufacturer and had another display developed just for us. We are the only Sur Ron kit that now uses our dedicated display. Its got our programming and logo on it, so lets see how long before we are copied again (PS, its really good to use!)

There is no actual need to to reset the display between voltages however, the battery status will show incorrectly if you do not. This is a simple few button press in the settings.

The important factors to remember are:

The battery if full at 75V and dead at 54v. Please note, a warm battery when charged will often after cooling drop to around 73V+. A low battery battery while under load (while using it) will cut around 53-54v, but may rise after cooling and resting to 56V. This is known as sag.


Sur Ron 67v Long range “Direct Swap” Battery *65Ah

High Power Sur Ron Battery 3900Wh  Samsung 21700 cell, with ANT Bluetooth BMS (works on IOS and Android) designed to fit inside the Sur Ron battery compartment utilizing the existing battery tray. The Cells are genuine branded cells specifically designed for large capacity storage and reliability. Other inferior cells used in cheaper packs simply can’t deliver like these. If you think the cost is high, these batteries have 208 cells that retail in the UK for around £6 each! not including: BMS, fabrication and shipping taxes.

The whole battery is fitted in  hand made stainless steel case designed to handle those inevitable and hopefully not painful “Offs” with hard off road rides and giving masses more protection. The casing is powder coated inside and out.

The battery does not have an integrated voltmeter. If you are using this with a standard controller, a handlebar voltmeter is supplied and can be simply plugged into the charge port of the battery to show voltage (empty at 48V). For after market controllers, that show battery voltage (like ASI) the voltmeter is not required.

Some versions of the Sur Ron controllers may go into limp mode if using this battery with no communication port (not using an aftermarket controller). This will need a very simple mod to the plug that normally connects to the battery. Please see the photo of the battery communication connector and the two pins that are crossed with a simple piece of: wire, or spade connector or similar piece of conductive metal. Note the area circled in red.

For bike that do not have a display to show voltage, We include a handlebar mounted display to be located on the throttle side. Simply plug into the charge port of the battery when riding.


Samsung 21700
18s 12p
Marathon 67v Battery = 10000W 155A DC
*65Ah, This is an equivalent if this battery were 60V. The 60v 63Ah has power capacity of 3750Wh this battery is higher at 3950Wh
Each cell with additional individual wrapping for added protection.
BMS monitoring individual series condition with balanced charging
An integrated handle for lowering the battery in and out.
Battery gauge to be seated on handlebars
Charging port via an XT60 connector – Will need our “Marathon charger” found here:
The main battery to controller connectors we use are the same type as used by Sur Ron to keep everything compatible. This allows you to swap your standard battery back should you wish.
Battery is in a super tough hand built stainless steel case designed to keep your battery safe in an accident and waterproof  except immersion or direct jet washing at the cable exits. Designed to fit straight into the bike and maximize the whole battery compartment (the hatch bolts need swapping  out with longer bolts that we supply – 2 minutes and simple). No movement- no rattles!
Your Sur Ron charger will recharge the battery, but to get full range, the standard SR charger can only go as low as 54V yet the battery can go as low as 28V

Please ALSO note, these are genuine new cells and made up into complete battery specially designed by us, built at our oversees  factory or here in the UK by our dedicated battery builders. We simply can’t buy a single battery, Thanks to Paypal fees, shipping and taxes the markup is minimal!

When connecting the battery to the bike and to avoid a spark. Turn the red trip switch on the bike to off.

Charging: First time charging is VERY important. Always connect the charger to the battery with the charger powered up from the mains. This will stop a “Connection Spark”. The battery needs a “Balance Charge” on first charge. Please charge for 12 hours first time.

Please note, charger is not supplied but can be found here:+


* 12 Month Warranty is for manufacturing defaults and does not cover misuse or accidental damage. These units are extremely strong and robust and will not let you down unless abused. We undertake warranties here in the UK. We take the pain!

Please note, Lithium batteries are considered hazardous and due care and attention should be taken. Although these cells are in wide use, and professionally manufactured in a purpose built factory; because of the power of the battery, we strongly recommend that precautions are taken. We do not recommend charging inside the family home and charging should be supervised. We take no responsibility for misuse. These batteries are thoroughly tested (full discharge and charge cycles at the manufacturing stage and also pre-delivery). These are not DIY or amateur built devices.

The controllers are fully bench tested working with a full working motor before leaving our premises. Any damage caused by your installation is not covered by our warranty. We highly recommend the use of one of recognized fitters where installation is fully covered.

Warranties are not transferable.

We reserve the right to slightly modify or change this product without notice.

Bike not included.



Buyer releases Electron Cycles or any person trading on or behalf of the business known as Electron Cycles from any liabilities, therein known as Electron Cycles (expressed or implied, arising by law or otherwise) that may occur from the use of products sold by Electron Cycles and purchased by Buyer. These products are being sold for “Off Road/Competition Use” only and may be used only on two wheel vehicles (bicycles, electric bicycles, two wheel electric powered vehicles) used solely for “Off Road/Competition” (off-road being defined as a private land with land owners permission and not public highway or byway). The Buyer also recognises that Lithium batteries are classed as hazardous and should not be: stored, used, charged in place, facility any area that is not fire proof or safe to do so. That batteries should not be taken into the family home, office, workplace or school place. No other applications are intended or implied. The Buyer of this product sold or provided by Electron Cycles acknowledges and agrees that the Seller disclaims any warranty and expressly disclaims any liability for personal injury or damages or any damages to vehicle, expensed occurred, personal property or third persons. Electron Cycles will uphold the warranty of the manufacture of the product sold for a period of six months from date of purchase from manufacturer defect. In the event a manufacturer’s warranty exists, it is agreed and stated that under no circumstances shall the seller or manufacturer be liable for any labour charged or travel time incurred in diagnosis for defects, removal, or reinstallation of this product, or any contingent expenses.



Additional information

Weight 19 kg
Dimensions 50 × 28 × 35 cm