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The AGM battery life expectancy may not be the first thing to be in your mind after purchasing an RV. But a short-lived power cell may interfere with the longevity of the motorhome and your experience when camping.

It is wise to investigate more about the battery, which is the lifeline of a motor vehicle and your RV lifestyle. If the battery type is AGM, you should know how long do AGM batteries last.

How Long Do AGM Batteries Last?

AGM batteries enjoy high popularity in the present era due to their features and longevity. However, as a user, you may wonder about its exact lifespan.

An AGM battery usually lasts between 3 and 5 years when used in ordinary situations. The good news is that you can extend the lifetime of AGM batteries up to 6 to 8 years under proper maintenance.

The Average Lifespan of an AGM Battery

How long do AGM batteries last? Well, the actual lifespan of an AGM unit depends on various factors. These include the charging system, usage, maintenance, battery type, and temperature.

As mentioned earlier, AGM batteries usually last for five years. Considering you keep it in 25ºC surrounding temperature, life expectancy up to 6 to 8 years is possible with float voltage, while 80% of the capacity is still intact.

Mostly, the manufacturers may recommend replacing the battery at this point. But there is no need for immediate replacement after 500 full cycles. Instead, you can continue using them till the usage period reaches seven years.

agm battery life expectancy
An AG’s average life is around 5 years. (Source: Emilian Robert Vicol / Wikipedia Commons)

Parameters That Affect the Battery Life

A large number of factors play a part when it comes to the life of the AGM batteries. The following parameters influence the lifespan regardless of the brand and model.

Battery Life Cycle

One battery life cycle means from being fully charged to discharged. Each battery comes with a designated life cycle. For AGM batteries, it ranges from 300 to 700 cycles when you use them in the prescribed condition.

Depth of Discharge Effect

A high volume withdrawal of power from a charged battery will cause a reduction in its cycle. It means, the harder a battery works, the sooner it loses its efficiency. The depth of charge and state of charge are inversely proportional.


When it comes to battery performance and its shelf life, the temperature is a vital parameter. The battery has to bear significantly more chemical activities inside it when the ambiance is warm. Hence, low ambient temperature beyond the suggested level will reduce battery capacity.

The recommended temperature range for most AGM batteries is 65 to 90 Fahrenheit. A temperature above this range will deteriorate the battery life cycle numbers.

Rate and Voltage of Recharge

Regulating the battery charging rate using a sophisticated digital system is very crucial. As per the working principle of a battery, the negative electrode produces hydrogen gas. On the other hand, a positive electrode generates oxygen gas.

A regulatory pressure valve makes sure that container pressure is up to the mark. VRLA (Valve Regulated Battery) system makes sure that hydrogen and oxygen gas do not escape into the outside environment, or else the battery inside will wither.

The AGM battery comes with a fixed charge storing capacity. The smart charging equipment will charge this battery slowly when it is almost full. A standard AGM battery accumulates 90% charge within 60% of actual full charging time. The remaining 40% of the time will require charging the rest 10% of the battery.

Sulfating and Corrosion

Chemical corrosion of battery electrodes is a widely known factor for decreasing battery life. It is the effect of the day-to-day use of a battery and its continuous aging.

Another condition that negatively affects battery life is sulfate building on the battery plates. Sulfate creates a layer on the battery plates, and hence these become incapable of holding charges. Ultimately this is the end of battery service life.

battery corrosion
Corrosion can reduce battery life. (Source: MarkBuckawicki / Wikipedia Commons)

Six Tips to Extend AGM Battery Life

How long do AGM batteries last? You’ve already got the answer! Do you want to extend that life? Here are some expert tips on extending the potential life range.

Regular Battery Charge

The more frequently you charge an AGM battery, the longer it lasts. This practice of regular charging makes it go on for at least five years. But remember not to overcharge the battery. It is crucial to find the perfect balance while charging at the right voltage. This habit will ensure extended battery service life.

Use of Smart Chargers

Battery conditions will improve drastically when smart chargers accompany it. These chargers can function rapidly and efficiently. Look for a charger that has auto voltage detection and cut-off features. Such characteristics will ensure that the AGM battery gets the correct voltage without getting an excess charge.

Use Temperature-Compensated Charging

The charging equipment must have a temperature compensated charging facility. It will adjust the temperature and enable battery charging in both cold and warm weather. Some of the latest charger models have an internal temperature-sensing probe. In traditional chargers, there are remote temperature sensors that work according to the climate.

Charging on Right Voltages

Correct float voltages are compulsory for AGM batteries to protect these from dying early. Also, try not to use chargers that have dip switches. These switches cause long term damage to the battery due to the lack of correct voltage.

Use Alternator Temperature Sensor

If it is possible to use an alternator temperature sensor with an external regulator, the alternator will receive low demand from the AGM battery. Alternators facing the high requirement for a prolonged time will cut the battery life short and cause battery failure.

Reduce Voltage Drop

To ensure the best charging performance, you need to reduce the voltage drop in the wiring system to a minimum. Even a small voltage drop will harm the battery life besides increasing the charging time.


Knowing how long do AGM batteries last will provide you a clear idea about AGM battery life expectancy. At the same time, following the tips will help with extending the lifetime of these batteries.

About Chris Coleman

Chris Coleman is an interesting travel blogger and outdoor photographer with a great sense of humor. He owns an RV Accessories shop in New York City so he has the knowledge necessary to provide thorough reviews and give advice on how to choose the right products for RV travel. He puts all that RV knowledge and experience to good use in his sharing posts. Besides product buying guides/reviews, Chris also writes informative articles, how-to articles and RV camping guides in his own interesting viewpoint. Chris’s blog is one of the most reliable information sources for RV campers no matter if you're an expert or a determined beginner.

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