The MillerTech 36V 50Ah Sport Series Bluetooth Lithium Battery (3650-BT) delivers reliable, lightweight power for compatible 36V trolling motors. Designed to replace three traditional 12V lead-acid trolling motor batteries with a single lithium battery, this LiFePO4 battery simplifies your electrical system while reducing weight and freeing up valuable battery compartment space.
With 50Ah of capacity, 1,920Wh of energy storage, and built-in Bluetooth monitoring, the MillerTech 3650-BT provides consistent voltage and dependable deep-cycle performance for serious anglers.
Key Features
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Single 36V Battery Solution: Replaces three 12V batteries connected in series in compatible 36V trolling motor systems.
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50Ah Lithium Capacity: Provides 1,920Wh of energy storage for trolling motor operation.
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Built-In Bluetooth Monitoring: Check battery charge level, voltage, and operating information using the MillerTech smartphone app.
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Lightweight Group 31 Design: Weighs just 33 lbs., significantly reducing weight compared to traditional three-battery lead-acid setups.
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LiFePO4 Technology: Delivers consistent voltage, long cycle life, and minimal maintenance.
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Integrated Battery Management System: Provides protection against overcharging, excessive discharge, overcurrent, and unsafe temperatures.
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Low-Temperature Charging Protection: Helps prevent charging when battery temperatures are too low.
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Marine-Grade Construction: IP65-rated battery case with molded hold-down strap grooves and a stainless steel breather vent.
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10-Year Manufacturer Warranty: Backed by MillerTech's Sport Series lithium battery warranty.
Specifications
| Specification |
Details |
| Manufacturer |
MillerTech |
| Part Number |
3650-BT |
| Series |
Sport Series |
| Battery Type |
Deep Cycle |
| Battery Chemistry |
LiFePO4 Lithium |
| Nominal Voltage |
38.4V |
| Capacity |
50Ah |
| Energy Storage |
1,920Wh |
| Battery Group Size |
Group 31 |
| Weight |
33 lbs. |
| Dimensions |
13" L × 6.75" W × 9" H |
| Maximum Charging Voltage |
43.2V |
| Low-Voltage Cutoff |
33V |
| Maximum Continuous Charge/Discharge Current |
50A |
| Peak Discharge Current |
150A |
| Bluetooth Monitoring |
Yes |
| Low-Temperature Charging Protection |
Yes |
| Battery Management System |
Yes |
| Case Protection |
IP65 |
| Manufacturer Warranty |
10 Years |
Designed for 36V Trolling Motors
The MillerTech 3650-BT is designed for compatible 36V trolling motor systems.
Replacing three traditional 12V batteries with one 36V lithium battery offers several advantages:
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Reduces battery weight and frees up compartment space
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Eliminates the need for series connections between three separate batteries
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Simplifies battery installation and maintenance
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Provides consistent voltage throughout the discharge cycle
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Allows battery status monitoring directly from your smartphone
Verify your trolling motor's voltage and maximum current requirements before installation. This battery has a maximum continuous discharge rating of 50A.
Important: This is a deep-cycle trolling motor battery and is not intended for engine starting applications.
Bluetooth Battery Monitoring
Built-in Bluetooth connectivity allows you to monitor battery performance directly from your smartphone using the MillerTech app.
View remaining battery capacity, voltage, charging and discharging information, and other operating data without accessing the battery compartment.
Charging Requirements
Use a compatible 36V LiFePO4 lithium battery charger.
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Maximum charging voltage: 43.2V
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Maximum charging current: 50A
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Built-in low-temperature charging protection
A standard 12V battery charger is not suitable for charging this battery.
This model features low-temperature charging protection but does not include an integrated battery heater.
Why Choose MillerTech?
The MillerTech 36V 50Ah Sport Series battery provides a practical upgrade for anglers looking to reduce weight and simplify their trolling motor battery setup. With a single-battery 36V configuration, Bluetooth monitoring, rugged marine construction, and a 10-year manufacturer warranty, the 3650-BT delivers dependable lithium power for compatible fishing boat applications.
