Battery Maintenance

What kinds of batteries do farms use?

Most farm engines use lead-acid batteries, including flooded and sealed types. Newer equipment and cordless tools use lithium-based packs, and some machines use deep-cycle batteries for lighting or electric fences. Each type has different charging and safety needs. Check the date on the battery or write one on it when it is installed.

Read the label and manual for the right size, type and charger. A charger made for one type can damage or ignite another.

Keep a spare battery for equipment you cannot afford to have down, such as a feed or water pump.

• Flooded or sealed lead-acid for engines
• Deep-cycle for slow, steady loads
• Lithium packs in cordless tools
• Match charger to battery type

How do you inspect and clean a battery?

Look at the case for cracks, bulges and leaks, and at the terminals for white or green corrosion. Wearing eye protection and gloves, clean terminals with a brush and a baking soda and water mix, rinse with care, dry well and tighten the clamps. Keep the top of the battery clean and dry. Check cable ends for frayed strands and green crust under the insulation, since corrosion can hide inside the cable.

Check that the battery is secured by a hold-down. A loose battery vibrates, shortens its own life and may short out.

Treat small leaks as a warning, and replace a leaking battery promptly.

• Look for cracks and bulges
• Clean terminals
• Tighten clamps
• Check the hold-down

How should you charge and test batteries?

Use a charger that matches the battery and follow its instructions. Charge in a ventilated space away from sparks, because lead-acid batteries can release explosive hydrogen gas. A voltmeter or a load test at an auto parts store or dealer can tell you how healthy a battery is. Slow charging at a low rate is gentler on a battery than a fast boost.

Do not charge a battery that is frozen, cracked or leaking. Let a cold battery warm up before charging, and never jump start a battery that looks damaged.

Record the voltage when you charge, and write down what you find. A slow decline is an early warning.

• Right charger for the battery
• Ventilated area
• No sparks nearby
• Never charge a frozen battery

How do you protect batteries in cold and heat?

Cold weather thickens oil and lowers battery output at the same time. Keep batteries fully charged, because a discharged battery can freeze. Block heaters, battery blankets and indoor storage help in hard winters. Extreme heat shortens battery life as well. Cold cranking ratings tell you how much power a battery gives in cold weather, so match the rating in your manual.

If a machine sits for long periods, use a maintenance charger if the maker allows, or disconnect the negative cable. Check the manual for the right method.

A battery tender is cheap compared with the cost of replacing batteries each year.

• Keep fully charged in winter
• Use blankets or heaters if needed
• Store indoors if possible
• Disconnect or maintain during long storage

How do you handle batteries safely?

Battery acid is corrosive and can burn skin and eyes. Wear eye protection and gloves, remove rings and watches, and never lay metal tools across terminals. If acid gets on skin or eyes, flush with water for several minutes and seek medical care. Call your local poison control line for advice.

Connect cables in the order the manual states. A common rule is to disconnect the negative first and reconnect it last, but check your manual.

Keep a box of baking soda and clean water close to where you charge batteries.

• Eye protection and gloves
• No metal across terminals
• Flush acid with water
• Call a doctor or poison control

When should you replace a battery and how do you dispose of the old one?

Replace a battery that will not hold a charge, shows damage or fails a load test. Match size, type and cold cranking rating to the manual. Date the new battery so you know its age. Keep your receipts, since many batteries carry a limited warranty from the seller.

Old batteries must not go in the trash or on the ground. Retailers and recycling centers often take them. Ask your county solid waste office, or the store where you buy the new one, about recycling.

Never mix old and new batteries in a bank or series if the manual warns against it.

• Fails a load test
• Cracked or swollen case
• Will not hold a charge
• Old and unreliable

Last reviewed: November 12, 2026. Written by the Rural Farm Life Editorial Team. See our editorial policy.