Lithium Power


Twice the power of traditional batteries.


MillerTech Lithium Batteries recharge up to 5x faster than a traditional battery and last up to 4x longer!


Bluetooth activated to connect directly to our MillerTech App. The MillerTech App gives you in depth, real-time data, taking the guessing game completely away. Power with Confidence!

Peace of mind

Over charge, over discharge, internal over temperature, voltage, short circuit and prismatic cell protection. Your safety is always our priority. No poisonous lead, no acid, and no creating gas during charge like traditional lead-acid batteries.

Proven Reliability

Millertech 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.


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!

Each battery is in a custom molded reclosable case that is sealed with a thick rubber gasket along the lid connection point. 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. The integrated hold-down strap grooves in side corners allow for a secure fit using straps or other options.

Top 5 Questions

Asked by MillerTech customers


Can I charge my Millertech battery with an alternator? 

Yes, you can, but only if your alternator’s max voltage output is 14.6 V or below. We have found there is a big difference in voltage output from one alternator to the next. Many alternators have an external regulator where you can adjust the output voltage. When using an alternator with high amperage output, always make sure and use ring terminal connection in order to get a good connection with no heat build up! If you want to use an alternator, but don’t know if it is compatible with lithium, please call us and we will try to help you with your decision!


Are MilerTech Lithium Batteries Safe?

Yes, Millertech lithium batteries are safe. Each and every Millertech battery is built using only the highest quality materials that are available. The lithium cells used in our batteries are UL, CE, Rohs, and RU approved, meaning they have successfully passed all safety testing. Including, but not limited to, steel rod, puncture test, dead short test, high voltage overcharge test, 30 ft. drop test, and crush test. Our batteries have been in fires (caused by other sources), and even though the plastic casing burned completely, our cells kept their shape and did not explode. All that being said, we still always encourage our customers to use caution and care when using a lithium battery. This is an electronic device that is capable of high electrical currents. The greatest chance of causing a problem will come from overcharging the battery. Our BMS system has a built-in overcharge protection that could fail in an extremely unlikely event, so it is important to use a charger that is compatible with lithium. If at any time you have questions about your current battery charger, please call us and we will help you evaluate your situation.

Lithium Batteries contain no poisonous lead, and no acid, and do not create gases during charge, as traditional Lead-Acid batteries do. Compared to lead-acid, Lithium Iron Phosphate batteries are also extremely lightweight, have a much lower self-discharge, do not sulfate, and are environmentally friendly.


Can Millertech lithium batteries be used to start an engine?

No, Millertech lithium batteries are not designed to be used in starting applications. Our batteries are designed to be used as a deep cycle lead-acid replacement. In certain small starting applications, we have successfully installed our 65AH or larger batteries with good results. For example, small gas engines and boat motors 50 HP or smaller. Or it is also convenient in some applications to connect 2 or 3 batteries in parallel to create the capability that is needed. If you have a starting application but are not sure if lithium is the right choice for you, please call us and we will help you make the correct decision!

Update for 2022! We are excited to announce that we now have a 100AH starting battery available. We recommend this model for any starting application besides large diesel motors, (100 hp or larger.)


Are Millertech lithium batteries a good choice for solar applications?

Yes, Millertech lithim batteries are a perfect choice for solar, wind, and other renewable energy applications. Our batteries are completely sealed, meaning there is no harmful gassing and corroding, making them perfect for installing in a basement or other confined environments. Most people know a large, heavily used, flooded battery pack needs a lot of attention and continuous monitoring to keep water levels and corrosion in check. In turn, a Millertech Life P04 pack requires zero maintenance or monitoring. Simply install it, set it, and forget it. Millertech solar batteries have 5000 cycles at 50% DOD, Flooded lead-acid (with correct care) have between 800-1000 cycles. Millertech solar batteries have between 5x – 6x the life of a flooded solar battery, but only cost 4x the price, plus you only need to pay for installing one Millertech pack versus 5 or 6 lead-acid packs! Efficiency: Millertech solar batteries are 98% efficient, meaning 98% of the energy collected by your panels is stored and is useable in the discharge stage. Flooded lead-acid after 100 cycles is only 60% efficient, meaning 40% of the energy collected is wasted! In conclusion, Millertech lithium batteries are the clear winner in solar applications. If you have questions about using Millertech lithium batteries for your solar application, please contact us for a free quote.


How do Millertech lithium batteries compare with other lithium batteries?

This is a question that we feel can only be truly answered with time. We do not know what type or grade of materials other batteries are made with. We do know that most any lithium battery will perform ok for the first 500 cycles, but in order to perform perfectly for 5000 cycles (at 50% DOD) and 10-20 years only the absolute best available components can be used in the manufacturing process. This is why Millertech does not buy an (off the shelf) lithium battery from just any Chinese supplier. When creating our Millertech brand in 2015, we soon realized how easy it is to buy a lithium battery from China. But finding one that could meet our requirements was not so easy, which is why we created our own specific spec sheet that states every component that we require to be used in building our batteries. We use only Grade A cells from the top 3 manufacturers in China. All Millertech batteries use commercial grade BMS’s that are oversized by at least 20A. Meaning a 40AH battery is only rated for 40A continuous charge and discharge but is actually capable of 60A! This, of course, costs us more, but the end result is a heavy duty, overbuilt, long-lasting product! All Millertech BMS’s are specially designed with high voltage withstand capability, (100 V), meaning our batteries can be connecting in series up to 48V with no chance of BMS failure. Our BMS’s also have a larger balancing current rate than off the shelf BMS’s, which will keep our batteries running at peak performance for thousands of cycles! In conclusion, we still have no way of truly comparing Millertech with any other brand, but rest assured when buying a Millertech battery, you are buying the best product we can possibly produce, with a 5 year free replacement warranty to back it up!

Top 3 Reasons your MillerTech Battery could fail.

(5 years of data analysis)


Water Damage.

The #1 reason batteries are sent back to us for warranty or repair is because of long term exposure to direct rain or wet conditions. We strive continuously to make our batteries more watertight. With this in mind, we still need to realize that creating a 100% waterproof battery would also create internal condensation and could also damage the circuitry. In our testing, we have found that exposing our battery to direct rain for up to 30 minutes had no effects on its performance. Long term exposure is where we see problems!


Abusive Charging.

All our batteries have built-in Battery Management systems, also called PCB-printed circuit boards. The PCB is designed to keep the battery safe and protect it from extreme situations. Unfortunately this PCB still has restrictions of what it is capable of. Charging a 45AH battery with a 100A, 18V alternator will most likely ruin the PCB and you will need to have it changed by a certified technician. Always make sure your charging source is lithium approved! If you’re not sure, give us a call and we would be happy to help!


Loose Connections.

Lithium Batteries are capable of releasing a lot of energy very quickly. Most of the time this is an advantage. In some cases users might choose to use clamps instead of ring terminals. Transferring high currents through a clamp is not safe or recommended. The connection point can almost instantly become very hot and unsafe. These high temps can melt the plastic casing around the terminal and cause the battery terminal/post to become dislodged. This could create a short circuit and will most certainly ruin your battery. Always use correct connecting techniques. Using battery clamps is not recommended. Remember Lithium batteries can store large amounts of energy and should always be treated with knowledge and respect!