12V 135AH Dual Purpose Starting Battery w/ BT (12135-DP)

Dual Purpose Batteries LiFeP04 are quickly becoming a popular item that many enthusiasts demand. Our team of Engineers and Technicians are a very aggressive group and were not willing to take a backseat on this trend. This battery has enough cranking amps to start even the largest engines in the industry, plus they have enough reserve capacity to power multiple power hungry graphs for 8 plus hours. These Dual Purpose models will change the way anglers think about there power needs forever.

Simple 10 Year Warranty
From the date of your battery purchase through year number 10 of ownership, your battery is covered. If it stops working during this time, we will repair or replace it with a battery of equal or greater value for FREE!

Recommended Charger
The Millertech 12V 40Ah lithium battery is engineered for a precise 14.6V charging profile.  For maximum performance, battery health, and a true 100% charge, the 12V-36V Dark Speed On The Run Dual Marine Charger is a great option! It will maximize your trolling motor run time by sending excess energy from your engine’s charging system, to your 12V-36v trolling motor batteries! We also have a 12V-24V option.
If you are not using it in a Marine setting, this charger is also a good option: 12V 20A On-Board Lithium Battery Charger (1220M)

The Sport Series Marine Batteries

The Sport Series Marine batteries are all sealed with a thick rubber gasket along the lid connection point. This means they are Marine approved IP65 rated. A completely sealed battery case will cause condensation, so we build them with a marine grade Stainless Steel breather vent. Our vent sits on the top of the case unlike some others where the vent sits down inside catching rain and dirt.

Custom molded, heavy duty, re-closable battery case. This means if you ever have an issue with your battery no matter is it in year 5 or year 15 we will always have easy access to repair any defective parts. This custom case also has convenient hold down strap grooves molded into the side corners helping to keep your straps seated securely in place.

BCI Group Size 31

(This is a standardized battery case size defined by the Battery Council International (BCI). It tells you the battery’s physical dimensions and terminal layout. If a vehicle or tray calls for Group 31, any Group 31 battery should physically fit and the cables should reach correctly.)

Weight – 33lbs

The battery weighs 33 pounds. It is significantly lighter than a comparable lead-acid starting battery, reducing overall vehicle or equipment weight.

Size – 13” × 6.75” × 9”

The battery measures 13 inches by 6.75 inches by 9 inches. Its Group Size31 dimensions allow it to fit standard battery trays designed for that footprint. Need a tray? Purchase them here.

Terminals
Built with heavy-duty M8 bolts/washers in 18-8 stainless steel. If multiple lugs are used, the washers may be removed, or longer bolts may be required to fully seat the bolt into the copper pillar.

Battery Management System (BMS)

The battery includes an integrated Battery Management System (BMS). The BMS protects against over-charging, over-discharging, excessive current, and unsafe temperatures to extend battery life.

Efficiency – 98%

The battery operates at 98% energy efficiency. This means nearly all stored energy is usable, resulting in longer run-times and faster charging.

Memory Effect

This battery has no memory effect. You can charge it at any state of charge without reducing overall capacity over time.

Built-In Bluetooth
Equipped with Bluetooth technology. The battery connects to an app that allows you to conveniently monitor multiple batteries at once—no more checking multiple apps. You can download the app here

Max Charge Voltage – 14.6V

The maximum charging voltage for this battery is 14.6 volts. Charging within this range ensures a full charge while protecting internal cells.

Max Charge / Discharge Current

The battery supports up to 100 amps of continuous charge and discharge current. This defines the safe operating range for sustained high-power loads and charging input.

Peak Discharge – 300A

The battery can deliver up to 300 amps for short bursts (up to 5 sec.). This allows it to support engine starting or sudden high-load demands.

Cut-Off Voltage – 10V

The battery has a built-in low-voltage 10V cut-off. This prevents over-discharge and protects the cells from damage to extend service life.

Operating Temperature:

The battery is designed to operate in temperatures ranging from 32°F to 130°F. This wide range allows reliable use in both cold and hot environments.

Low-Temperature Charging Protection 

The battery includes built-in low-temperature charging protection. This prevents charging in freezing conditions to protect the cells. Charging Temp. Range: 25°F-131°F

Cell Type – Prismatic

This battery is constructed using prismatic lithium cells. Prismatic cells allow higher capacity.

Robust Design  for Longer Life
Robust yet lightweight, Millertech Sport Series Lithium Batteries can last up to 10X longer than AGM or lead-acid batteries. Never be stranded with a dead battery again!

THE MILLERTECH® SPORT SERIES LITHIUM BATTERY
10 YEAR GUARANTEED WARRANTY IS SIMPLE!

TERMS:

From the date of your battery purchase through year number 10 of ownership, your battery is covered. If it stops working during this time, we will repair or replace it with a battery of equal or greater value for FREE!

SHIPPING:

We cover all shipping costs associated with shuttling your battery back and forth for repair or replacement. It is our warranty; it is our cost; not yours.

EXCLUSIONS:

There are NONE! You trusted Millertech®, and if it’s within the warranty period your Millertech® battery is completely covered for everything!

PROOF OF PURCHASE:

You don’t need one. If it’s Millertech®, it’s covered!

FOR WARRANTY SERVICE CALL: 855-MAX-LITH

EMAIL:  warranty@millertechenergy.com