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Lead-acid glass mat batteries, often referred to as AGM batteries, are a type of rechargeable battery commonly used in vehicles, boats, and backup power systems. They are used in many of BestTugs tugs for their safety record, composition and weight. Weight on a tug provides traction. Like all batteries thought, they will eventually need to be replace. Here's why they fail and how you can extend their lifespan in simple terms:

Why AGM Batteries Can Fail:

Sulfation: Over time, a chemical reaction can occur in the battery that forms a layer of lead sulfate on the battery plates. This is called sulfation and it reduces the battery's ability to hold a charge.

Aging: Like all batteries, AGM batteries naturally degrade with age. The materials inside the battery wear out over time, which reduces their overall performance.

Overcharging or Undercharging: If a battery is consistently overcharged or undercharged, it can cause damage to the cells and plates inside, which can lead to a shortened lifespan.

Excessive Heat: High temperatures can speed up chemical reactions inside the battery, which can cause it to wear out faster.

Advantages of AGM Batteries over flooded lead acid

  • Spill-proof: through acid encapsulation in matting technology

  • High specific power: low internal resistance, responsive to load

  • Faster Charging:Up to 5 times faster charge than with flooded technology

  • Cycle Life: Better cycle life than with flooded systems

  • Water Retention: Water retention (oxygen and hydrogen combine to produce water)

  • Durability:Vibration resistance due to sandwich construction

  • Stands up well to cold temperature

  • Less prone to sulfation if not regularly topping charged

  • Has less electrolyte and lead than the flooded version

Advantages of AGM Batter

ies over Lithium Batteries

AGM (Absorbent Glass Mat) batteries and Lithium-ion batteries each have their own strengths and applications. Here are some advantages of AGM batteries over Lithium-ion batteries:

  • Familiar Technology: AGM batteries have been around for a longer time and are well-established in various industries. This means they are a known and trusted technology with a proven track record.

  • Maintenance-Free: AGM batteries are typically considered "maintenance-free" because they don't require regular watering or electrolyte checks. This can save time and effort in terms of battery care.

  • Durability: AGM batteries are known for their ruggedness and ability to withstand rough handling. This makes them a popular choice for applications where the battery might experience vibration or shock.

  • Safer Chemistry: AGM batteries are considered safer in terms of their chemistry. They do not contain potentially hazardous materials like cobalt, which is found in some Lithium-ion batteries.

  • Wider Operating Temperature Range: AGM batteries can perform well in a broader range of temperatures compared to many Lithium-ion batteries, which can be sensitive to extreme heat or cold.

  • Readily Available: AGM batteries are widely available and can be found in most locations, making them easy to source for various applications.

  • Easy Replacement: Since AGM batteries are commonly used, finding replacements is straightforward, and they can often be swapped out without much hassle.

  • Compatibility with Existing Systems: AGM batteries can often be used as a direct replacement for traditional lead-acid batteries in existing systems, making them a convenient upgrade option.


Batteries are expensive. Here are some steps to Prolong their Life:

Charge Properly: Ensure the battery is charged correctly. At BestTugs we use premier chargers/tenders to ensure that we eek out the longest life possible from our tug batteries.

Avoid Extreme Temperatures: Try to keep the tug battery in a cool, dry place. Extreme heat or cold can accelerate the aging process.

Regular Maintenance: Check the battery terminals for corrosion and clean them if necessary. Also, inspect the battery for any signs of damage or leaks.

Avoid Deep Discharges: Try not to let the battery completely discharge too frequently. It's better to recharge it before it gets too low.

Keep the battery topped Up: If the tug isn't going to be used for an extended period, it's a good idea to give it a top-up charge every few months, or simply leave it on the smart charger provided with the tug.

Remember, while these steps can help prolong the life of an AGM battery, all batteries have a limited lifespan, and eventually, they will need to be replaced. Following these tips, however, can help you get the most out of your battery.

When it is time to replace your batteries give us a call. We generally ship the same day right to your tugs location.

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