In the Shop: Baby Your Battery

March 9, 2013 03:11 PM
In the Shop: Baby Your Battery

Some folks get five, maybe six years of use from batteries in their trucks, tractors, combines and other machinery. Others feel lucky if they get a battery to last three years.

While luck plays a role, proper care and maintenance are sure bets to optimize battery longevity.

A hard life. The worst scenario for a battery is inactivity, but over-activity is almost as bad. That’s because batteries "like" being moderately discharged and then recharged, but "dislike" being completely discharged or being used frequently without adequate recharging.

Both extremes of battery abuse are common with farm equipment. Combine, self-propelled sprayer and many four-wheel-drive tractor batteries sit in storage for nine months a year. Any battery filled with electrolyte will naturally slowly discharge over time. That’s one reason why battery manufacturers often ship new batteries "dry."

Unless batteries are occasionally recharged during storage they can suffer damage that reduces their lifespan.

At the other extreme of battery abuse are batteries that work frequently but never get a chance to fully recharge. The largest demand on a battery is starting a motor. It takes at least a few minutes, maybe up to a half hour, for a machine’s alternator to fully recharge a battery. Depending on the alternator’s capacity and how discharged the battery is, a battery can slowly lose charge if a machine is frequently started but not allowed to run long between start-ups.

Batteries in ATVs and utility vehicles are prime examples.

Add corroded battery terminals and sketchy wiring insulation that decreases the ability of the alternator to recharge the battery, and the battery dies a slow death even though the machine gets frequent use.

Sluggish performance. Modern electrical add-ons frequently found in tractor cabs can tax the electrical systems on older tractors. Older machines that are equipped with lots of spray monitors, seed monitors, row guidance and other electronic wizardry, might not have an alternator large enough to power all the extra components.

If the alternator can’t meet electrical demands, the battery makes up the deficit until tractor headlights or electrical systems slowly fade or shut off as the battery drains.

Cold temperatures put a double-whammy on batteries by congealing engine, transmission and gearcase oils, which increases battery loads during starts. The best way to start engines in cold weather is to use an engine block heater that keeps engine oil warm and free-flowing.

There is no such thing as a truly maintenance-free battery. Any battery with caps or check plugs should have the electrolyte level checked regularly. Electrolyte should be topped off as needed to keep fluid to the bottom of the slot in the tube below each cap or plug when necessary. Never add battery acid; add only distilled water.

Handle with care. Even if a battery doesn’t have caps or plugs to check electrolyte levels, a few maintenance steps can improve battery longevity.

Remove battery cable clamps from batteries at least once a year to check for good contact between the outside of battery posts and the inside of battery cable clamps/connectors. Use a battery post cleaning tool to remove corrosion and expose bare metal on the outside of battery posts and the inside of cable clamps.

Good metal-to-metal contact between battery posts and cable clamps ensures maximum conductance to start engines and allows the alternator to feed power back into the battery.

Chemically treated fiber "battery terminal washers" placed between battery posts and the bottoms of battery cable clamps as part of maintenance can reduce the slimy yellow corrosion on battery clamps and cables. Spray-on battery corrosion inhibitors also work well. Plain old bearing or axle grease is messy, but when smeared over battery posts and connectors, is a low-cost, old-school way to protect battery posts and cable connectors from corrosive vapors.

Cool Tool

battery tester

A pocket-size $80 to $150 electronic "battery load tester" can quickly determine if a battery merely needs to be recharged or if it needs to be replaced. Load testers simulate a "load" during testing, giving a more reliable indication of battery condition than testers that measure "surface charge" of the battery.

Be sure to visit Dan’s "In The Shop" blog at, where he’ll share more tips and insights. Send comments and story suggestions to

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