The MillerTech 12V 55Ah Sport Series Bluetooth Lithium Battery (1255-BT) delivers reliable deep-cycle power for trolling motors, fish finders, forward-facing sonar, and other marine electronics. Featuring LiFePO4 technology, built-in Bluetooth monitoring, and a lightweight 17.1 lb design, this battery is an excellent choice for anglers looking to reduce weight while maintaining dependable power on the water.
With 55Ah of capacity and 704Wh of energy storage, the MillerTech 1255-BT is ideal for dedicated electronics installations, smaller fishing boats, kayaks, and compatible trolling motor systems.
Key Features
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55Ah Lithium Capacity: Provides 704Wh of energy storage for trolling motors and marine electronics.
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Built-In Bluetooth Monitoring: Check battery voltage, remaining capacity, and operating information using the MillerTech smartphone app.
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Lightweight Construction: Weighs just 17.1 lbs., making it easy to install in smaller battery compartments.
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LiFePO4 Technology: Delivers consistent voltage, long cycle life, and low maintenance requirements.
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Integrated Battery Management System: Protects against overcharging, overdischarging, excessive current, and unsafe temperatures.
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Low-Temperature Charging Protection: Prevents charging under unsafe cold-temperature conditions.
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Marine-Grade Construction: IP65-rated battery case with a stainless steel breather vent and molded hold-down strap grooves.
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Compact Design: Measures just 9" × 5.5" × 8.5".
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10-Year Manufacturer Warranty: Backed by MillerTech's Sport Series lithium battery warranty.
Specifications
| Specification |
Details |
| Manufacturer |
MillerTech |
| Part Number |
1255-BT |
| Series |
Sport Series |
| Battery Type |
Deep Cycle |
| Battery Chemistry |
LiFePO4 Lithium |
| Nominal Voltage |
12.8V |
| Capacity |
55Ah |
| Energy Storage |
704Wh |
| Weight |
17.1 lbs. |
| Dimensions |
9" L × 5.5" W × 8.5" H |
| Maximum Charging Voltage |
14.6V |
| Maximum Continuous Charge/Discharge Current |
55A |
| Peak Discharge Current |
180A for 5 Seconds |
| Battery Terminals |
M8 |
| Bluetooth Monitoring |
Yes |
| Low-Temperature Charging Protection |
Yes |
| Case Protection |
IP65 |
| Manufacturer Warranty |
10 Years |
Trolling Motor & Marine Electronics Applications
The MillerTech 1255-BT is well suited for a variety of deep-cycle marine applications, including:
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Compatible 12V trolling motors
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Dedicated Garmin LiveScope electronics installations
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Lowrance ActiveTarget and Humminbird MEGA Live systems
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Fish finders, GPS displays, and marine networking equipment
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Fishing kayaks and small boats
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Compatible 24V or 36V trolling motor systems using multiple 12V batteries connected in series
A dedicated lithium battery can help separate electronics power from the engine cranking battery, reducing the risk of draining starting power during long days of fishing.
For trolling motor installations, verify the motor's current requirements and MillerTech's approved series-connection guidelines before installation.
Important: This is a deep-cycle 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 battery charge level, voltage, current, and other operating information without accessing your battery compartment.
Charging Requirements
Use a compatible 12V LiFePO4 lithium battery charger.
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Maximum charging voltage: 14.6V
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Maximum charge current: 55A
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Built-in low-temperature charging protection
This battery does not include an integrated heater. Low-temperature protection prevents charging when conditions are unsafe rather than actively warming the battery.
Why Choose MillerTech?
The MillerTech 12V 55Ah Sport Series battery provides dependable lithium power in a compact, lightweight package. Whether you're powering a dedicated electronics system or upgrading a smaller trolling motor battery setup, the 1255-BT combines Bluetooth monitoring, marine-grade construction, and a 10-year manufacturer warranty.
