Battery Maintenance Tips

For Common Types of Batteries Around The Farm

Battery Maintenance Tips

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Your truck, small farm tractor, ATV, RV, and small farm generator all have one thing in common. They all use batteries. In this article we discuss the common types of lead acid batteries you have around your farm or homestead, their uses, and battery maintenance tips for optimum life. 

What Kind Of Battery Do You Have?

Your car, truck, ATV, tractor, backup generator, etc. have a starting battery, sometimes called a surface charge battery. These put out a tremendous amount of current in short bursts of use. They are designed to be kept fully charged at all times. The state of charge should never be lower than 80%  

Your electric fence charger, RV, boat trolling motor, hydraulic dump trailer, etc. have a cycling battery, also called a deep cycle battery. They put out a lower current for longer periods of time. These are designed to discharge down to 50% without sustaining damage. 

Battery driven vehicles like golf carts, battery powered forklifts or scissor lifts, and power wheelchairs use extreme deep cycle batteries, sometimes called true deep cycle. These are designed for steady continuous draw and can be drawn down to almost dead without damage to the battery. 

What Types Of Batteries Are Available?

An open topped, lead acid battery, also known as a watering battery, or conventional battery is a proven design that has been around for many years. These allow you to add water when it evaporates out. They are often more affordable, but require more attention to battery maintenance tips. They are more likely to leave acid residue on the battery cables and tray. This type of battery does not work well when the vehicle design makes it hard to get to the battery. This option is available in starting, deep cycle, and extreme deep cycle batteries.

Maintenance-free batteries became commonplace in the 1980s. These are less likely to need water, but you can add it if necessary. These are still considered conventional batteries as you can add water and they can spill. They are less likely to corrode battery cables and deposit acid in the battery tray. Maintenance-free but not sealed is a common passenger car battery. 

Opened maintenance free battery. Top etch is activation date. Middle etch is manufacture date code.

Sealed batteries are completely maintenance-free and spill-proof. With these you should never see corrosion on battery cables or acid residue in the tray. These have become very common in recent years. The two types of sealed batteries you are likely to encounter are absorbed glass mat (AGM) and gel. The most common is AGM. The only disadvantage to this type of battery remains cost. These are also available in starting, deep cycle, and extreme deep cycle. 

When Was Your Battery Made?

Battery maintenance tips include determining battery age. Most batteries have a code that tells the date of manufacture. This enables you to know not only how old a battery is when you buy it, but the age of the battery in your vehicle or farm tools

Battery manufacturers use different codes etched into either the plastic case or the terminal. The most common code starts with a letter designating the month (A = Jan, B = Feb. etc.), followed by a number designating the year. By this code, a battery manufactured in August of 2019 reads H9XXX. In Exide batteries, the first digit denotes build location. The next two digits show day of the month. The fourth digit, a letter, shows the month. The fifth is a number showing the year. A battery manufactured August 21st, 2019 would read X21H9XX. 


The manufacture date is not always the activation date. Jeremy Boback of Exide Battery said, “If the battery is is difficult to make, and we don’t want to keep switching lines to make smaller batches, we can make a larger group of them and be able to store them dry, then fill and form them later.” In those cases, the battery will have both a manufacture date code and an activation date code. 

Sometimes batteries bear stickers with a month and year on them. These stickers indicate the date the distributor recharged it and certified its voltage and health. Do not confuse this with either a manufacture or activation date.

Dry vs. Factory Activated

A battery that has been manufactured, but the electrolyte not yet added, can be stored dry indefinitely. When the electrolyte (battery acid) is added, the battery is “born.” Its life expectancy from that date matches that of a filled battery from the date of manufacture. 

Left battery is dry. Right battery is pre-filled.

The only batteries you can buy dry are small powersports (ATV, motorcycle, snowmobile) batteries. A dry battery comes with a package of electrolyte. Battery numbers are fitment codes, and often give this information. For instance, a Yuasa FAYTX14AH-BS is the factory activated version of the YTX14AH-BS, which comes dry. If uncertain the filled or activated status of a battery, ask the retailer or peek inside the box for that pack of acid. 

What If Your Battery “Goes Dry”?

Battery electrolyte is a mixture of sulfuric acid and water. To avoid creating mini bombs, manufactures vent all batteries in some way. Over time, water evaporates. Normal evaporation works slowly enough not to be a problem most of the time. Heat and overcharging accelerate evaporation, releasing hydrogen gas which is toxic and highly explosive. Always charge batteries in an area with adequate ventilation. 

It’s important to check the electrolyte level in non-sealed batteries. Some have translucent sides with minimum and maximum lines printed on the side. With opaque batteries, you must remove the cap and make sure the electrolyte is covering the lead plates, but not deeper than the bottom of the tube in the fill hole. 

Correct electrolyte level.

If the level is low, add distilled, deionized (DI), or reverse osmosis (RO) water. “Basically, water that had the impurities removed from it,” said Jeremy. “If you add something like tap water, it could have iron or some other element in it, which is bad for the battery. Don’t use acid to refill a battery if it just lost water from usage and evaporation. Only add water.” Adding electrolyte changes the ratio of water and acid in the battery. 

Most Batteries Don’t Die. They’re Killed.

Sulfation is the number one cause of early battery failure. A battery loses voltage like water evaporates out of a cup. If you’re putting water back into the cup, it never gets empty. So it goes with battery voltage. If you use the machine, the charging system refills the battery. If the machine sits unused, and the voltage drops low enough, sulfation occurs. If you overcharge your battery, sulfation occurs. Overcharging happens if you use too large of a charger, leave the battery on too long, or your vehicle’s charging system puts out too much voltage. If the battery sits for a long time at a high temperature (above 75 degrees F), sulfation occurs faster.  

Outlined areas show the white of sulfation.

Most battery maintenance tips focus on preventing sulfation. Try thinking of sulfation as a battery version of rust. In sulfation, lead sulfate crystals build up on the lead plates of the battery. This impedes the chemical to electrical conversion and drops the voltage output of the cells affected. 

Battery Maintenance Tips

  1. Check battery electrolyte level regularly unless you have a sealed battery. 
  2. Do not let your battery sit in a discharged state. Either use it regularly or use a battery maintainer. 
  3. Check the voltage output of your equipment to make sure it is not overcharging.
  4. Use the correct charger for the size of your battery (don’t use a 20 amp charger on an ATV battery). 
  5. If you have to charge your battery, use a charger that shuts off automatically when the battery is fully charged. With older chargers, do not leave the battery on the charger longer than the recommended amount of time for that battery. 

Originally published in Countryside January/February 2020 and regularly vetted for accuracy.

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