For our 12V batteries, set the bulk and absorption stage between 14.2V and 14.6V, and never above 14.6V. Lithium doesn’t need a float stage, but a float of 13.5V to 13.8V is fine when you’re plugged into power. With several batteries in parallel, let absorption run at least 20 minutes per battery so they balance.

The battery, a battery charger, an adjustable mounting strap and three connector cables that fit most major trail camera brands (5.5mm x 2.1mm, 4.0mm x 1.7mm and 4.8mm x 1.7mm). The USB hub, security camera adapter, splitter and 6V converter are sold separately.

The BMS is the battery’s built-in brain. It watches voltage, current and internal temperature, and it protects against:
• Overcharge and over-discharge
• Over-temperature
• Short circuit
• Reverse polarity and over-current (through a dual-blade fuse)
Millertech uses a commercial-grade BMS sized at least 20A above the battery’s rating.

The Millertech app for iOS and Android shows:
• Remaining capacity, total capacity and amp hours
• Voltage and current
• Temperature
• Recharge cycle count
• Battery status and an error log
You can also give each battery a name, like “Trolling” or “Cranking.”

Every Sport Series battery has a 10-year warranty from the date of purchase. If it fails, Millertech will repair it or replace it with a battery of equal or greater value, free. Millertech pays shipping both ways: “It is our warranty; it is our cost; not yours.” The warranty page lists no exclusions, and you don’t need proof of purchase

Fish finders and LED lighting, too. Fish finders need a cord sold separately.

Two things to check:

• Charger or converter: use one built for lithium. An old lead-acid charger could overcharge a lithium battery, or it may not have enough voltage to charge it fully.
• Terminals: use ring terminals, torqued to 10 ft-lb.

If you're not sure about your setup, call our Support Team at 855-MAX-LITH before you buy.

Most Millertech marine batteries come in Group 24 or Group 31 cases:
• Group 24: 12V 100Ah Dual Purpose (heated and standard), 24V 50Ah
• Group 31: 12V 135Ah and 190Ah Dual Purpose, 24V 80Ah, 36V 50Ah and 60Ah
• Group U1: 12V 40Ah Dual Purpose
The 36V 105Ah measures 13.5 × 9.6 × 10.5 in and needs its own tray.

The Battery Management System (BMS) puts the battery into low-voltage protection (sleep mode) to protect the cells. To wake it, connect a lithium charger, a jump pack, or another battery that’s at least 50% charged. The Dark Speed and three-bank chargers have a built-in BMS wake-up. The app shows remaining capacity in real time, so you’ll see it coming.

A heated battery has a built-in heater that turns on when the charger is connected and the temperature is below 32°F. It warms the cells to 34°F, then resumes charging. That lets you charge in the cold and fish down to 0°F. If you fish late fall, winter or early spring and keep the boat outside, it’s the one to get.

Heated Sport Series models:

• 12V 100Ah and 135Ah Dual Purpose
• 12V 300Ah
• 24V 80Ah
• 36V 60Ah

It’s a compact, rechargeable lithium battery pack, designed by Millertech, that powers your trail camera for months at a time so you’re not hiking in to swap AAs. Hang it on the tree next to the camera and plug it in. Add the slide-on USB hub and the same battery becomes a power station for phones, tablets and other USB gear at camp, on the boat or in the blind.

The maximum number of batteries that can be connected is four, whether in a series or parallel configuration.