12V 15AH Sport Series Lithium Battery w/ BT (1215-BT)

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!

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.

Recommended Charger
The Millertech 12V 15Ah lithium battery is engineered for a precise 14.5V charging profile.  For maximum performance, battery health, and a true 100% charge, the Millertech 12V 5A Lithium Battery Charger (125C) is strongly recommended.

Storage Capacity -15Ah

This battery has a storage capacity of 15 amp-hours (Ah). That means it can deliver steady power for small devices over extended periods without frequent recharging.

Voltage – 12.8V

The battery operates at a nominal voltage of 12.8 volts. This makes it a direct lithium replacement for standard 12V lead-acid batteries while delivering more consistent power.

Weight – 3.1 lbs

The battery weighs just 3.1 pounds. Its lightweight design makes it ideal for portable applications where reducing overall weight is important.

Size – 6″x4″x4″

The compact size of this battery is 6 inches by 4 inches by 4 inches. Its small footprint allows it to fit easily into tight spaces where traditional batteries won’t.

Battery Management System (BMS)

The battery includes an integrated Battery Management System (BMS). The BMS protects the battery from over-charging, over-discharging, excessive current, and unsafe temperatures.

Max Charge Voltage:
14.6V or 3.75V per cell.  If an individual cell voltage exceeds 3.75V during
charging, the BMS will prevent a charge current from continuing. Discharge is always allowed under this condition.

Cut Off Voltage: 10V
If an individual cell falls below 2.5V during discharge, the BMS will prevent further discharge. Although the battery is in “low-voltage disconnect” mode, it will still allow a charging current.

A passive balancing process is activated by the BMS at the top of each charge cycle, when the battery voltage exceeds around 14.6V. This ensures that all the cells remain at the same state of charge, which aids in pack longevity and performance.

Peak Discharge – 45A (3 Seconds)

The battery can deliver a peak discharge current of 45 amps for up to 3 seconds. This allows it to handle short bursts of high power.

Built-In Bluetooth

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

Chemistry – LFP (Lithium Iron Phosphate)

This battery uses Lithium Iron Phosphate (LFP) chemistry. LFP is known for exceptional safety, long cycle life, and stable performance compared to other lithium types.

Efficiency – 98% 

The battery operates at 98% energy efficiency. This means nearly all stored energy is usable, resulting in less waste and longer runtime per charge.

Memory Effect – None

This battery has no memory effect. You can charge or discharge it at any level without reducing its overall capacity over time.

Cell Type – Cylindrical

The battery is built using cylindrical lithium cells. Cylindrical cells are known for consistent performance, durability, and effective heat management.

Terminal – Spade/F2

This battery has a F2 Spade. (0.250″ quick-disconnect)

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.

Be sure to download the product manual for more details.

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