MadJax Ascent (All Years) (48V) Fleet Lithium Conversion Kit
MadJax Ascent (All Years) (48V) Fleet Lithium Conversion Kit - 51V 65Ah Backordered — estimated to ship Sep 15
10-Year Warranty / 5,000+ Cycles
10-Year Warranty / 5,000+ Cycles
Built for the long haul. Every Promise-series battery is backed by a 10-year manufacturer's warranty and rated for 5,000+ cycles at 80% depth of discharge. View full warranty details.
Product Highlights
Product Highlights
MadJax Ascent (All Years) (48V) Fleet Lithium Conversion Kit
Upgrade Your MadJax Ascent to Fleet Lithium
Replace the factory lead-acid batteries in your MadJax Ascent with a single, high-performance 51V LiFePO4 pack from Fleet Lithium. Complete conversion kit included.
Choose Your Capacity
| Capacity | Range | Best For |
|---|---|---|
| 51V 65Ah | Up to 27 mi | Stock carts only |
| 51V 105Ah | Up to 50 mi | Daily driving |
| 51V 168Ah | Up to 75 mi | All-day use |
| 51V 210Ah | Up to 90 mi | Max range |
65Ah is for stock motors/controllers only.
What's Included
- 51V NexGen Fleet Lithium LiFePO4 Battery (selected capacity)
- CH5618 — 58.4V 18A LiFePO4 Smart Charger
- BR5216 — MadJax Ascent Bracket Kit
- AC0219 — AC Power Connector
- CB0917 — Cable Set (35.4")
- Digital State-of-Charge Gauge
- All mounting hardware
Key Specs
- 300A NexGen BMS with 800A peak surge
- Patent-pending fire suppression system
- Built-in cold-weather heater — activates automatically below 32°F
- Bluetooth monitoring
- 10-year warranty — designed and assembled in the USA
Fitment Guide
| OEM | Model | Years | Factory Voltage |
|---|---|---|---|
| MadJax | Ascent | All Years | 48V |
Controller Compatibility
MadJax Ascent models use a 48V controller. The Fleet Lithium 51V pack is compatible. Verify your controller model before ordering.
Will this fit my MadJax Ascent?
Yes. The BR5216 bracket kit provides a factory-fit installation.
Does my controller need reprogramming?
In most cases, no.
Does it work in cold weather?
Yes. Built-in heater activates automatically below 32°F.
*Range estimates are maximums under ideal conditions.
Quick answer: the MadJax Ascent (All Years) (48V) Fleet Lithium Conversion Kit from Fleet Lithium has nominal voltage 51.2V, capacity 105 AH, continuous / peak discharge 300A continuous / 800A peak surge, cycle life 5,000+ cycles at 80% Depth of Discharge (DoD), cell chemistry Lithium iron phosphate (LiFePO4), warranty 10 Year Warranty. The complete specification table for this configuration is below.
Electrical & Performance
- Nominal Voltage
- Factory Pack Voltage
- Capacity
- Nominal Energy
- Continuous / Peak Discharge
- Charging Voltage
- Charging Current
- Discharge Cutoff Voltage
- Cycle Life
Battery & BMS
- Cell Chemistry
- Battery Type
- EV Battery Type
- BMS Features
- 300A Continuous / 800A Peak Surge Discharge , Advanced Battery Management System (BMS) , Internal Heating for Cold Temp Charging , Patent-Pending Fire Suppression System , Bluetooth Communication with BT 5.0 , Active Cell Balancing for Extended Life Cycle
- Safety Features
- Thermal Regulation (Heated Cells) , Built in Fire Extinguishers , Low Voltage Disconnect (LVD) , Low Temp Charging Cutoff , Over Charge / Discharge Protection , Over Current Protection
- Battery Features
- EV Battery Features
- Operating Temperature
- Charging: 32 to 140 ºF (0 to 60 ºC) , Discharging: -4 to 149 ºF (-20 to 65 ºC)
Dimensions & Weight
- Dimensions (L x W x H)
- Weight
- 80.0 lb
Fitment & Compatibility
- Make
- Model
- Model Number
- Motor Controller
Warranty & Compliance
- Warranty
- Certifications
- UL 1642 , UL 1973 , CE , RoHS , UN38.3 , IP67
- Standards
- Condition
- Manufacturer Relationship
Product Details
- Classification
- Colour / Finish
- Vendor
- Fleet Lithium
- Product Type
- Lithium Battery Conversion Kit
- SKU
- MJ5216065
Let customers speak for us
GREAT SERVICE
Awesome kit. We Live in a very cold climate, our ranger gets a ton of use year round and especially during the winter so the cold weather performance was a must for us. We've had the kit installed for about a year now and it's been perfect. Customer service has been super helpful the one or two times we had questions and we've got a couple of neighbors who run the kits as well and they say the same thing. Kevin and his crew are really top notch!
The 12V voltage reducer corrected the unstable behavior that had affected the lights and other accessories. The output has remained steady through regular use.
The 51V replacement charger is easy to keep available as a backup and works without unnecessary controls. The battery reaches a complete charge consistently during normal use.
The Polaris Ranger EV bundle lined up well with the intended mounting area and the connections were easy to identify. Once installed, the vehicle felt smoother and more consistent through normal use.
The 51V replacement charger connected as expected and has charged the compatible battery consistently. The status indicators are easy to follow, and the unit feels solid in regular use.
Easy installation and great technical support.
After installing the Club Car 48V kit, throttle response felt more immediate and the vehicle no longer felt sluggish late in the charge. The cleaner battery compartment is another welcome improvement.
Cabels look great. Will be installing them by the end of the week. Frank
The BlueMax 200Ah marine battery has provided steady power for onboard electronics and normal time on the water. It is easier to handle than the older battery and has required very little attention between trips.
The parts for the EZGO TXT kit were organized clearly and the installation sequence made sense. The finished setup looks tidy and removes the routine upkeep of the old battery bank.
The 76V replacement charger replaced the previous unit without requiring a complicated setup. Charging has been predictable, and the connector fits securely.
The plug on the 51V replacement charger seats firmly and the unit maintains a normal charging cycle. The battery has been ready for use each time charging is complete.
The parts for the EZGO RXV kit were organized clearly and the installation sequence made sense. The finished setup looks tidy and removes the routine upkeep of the old battery bank.
The 12V voltage reducer provided a clear path for running standard accessories from the higher-voltage battery system. The result has been reliable and easy to service.
