How to Maintain Batteries in the Cold

It’s been cold, and it could be a long and even colder winter.  That presents some good news and some bad news for electric equipment. First, some good news:  It’s not easy to lower the temperature of a GSE battery.  A typical baggage tractor battery weighs more than 3,000 pounds, which is too much mass to lower the internal temperature over the course of a day or two.  And even if internal temperature drops, the electrolyte in a charged battery will not freeze.  And ultimately, batteries like the cold.  Lower average lifetime battery temperature means longer life expectancy (all other things being equal). So in most cases, freezing temperatures don’t make any difference at all, and possibly they even help. Here is the bad news:  If you strand a tractor on the ramp for days, the battery temperature will eventually drop to ambient.  And if the battery is discharged, the electrolyte is mostly water and will freeze around zero degrees Fahrenheit.  If you water a battery and don’t give the charger a chance to mix the acid, that water will stay on top and freeze close to 32 degrees Fahrenheit. Lower internal battery temperature means lower capacity. The battery will deliver as little as half the power of a warm battery, at a time when the tractor probably needs more power to do the same work. Then the tractor hits creep mode quickly and just can’t keep up with demand. Battery voltage on charge is artificially high in cold temperatures.  Some old chargers will shut off long before the battery reaches 100 percent, further reducing capacity and inadequately mixing the electrolyte. What to do: Keep going: discharging and charging a battery will keep it warm enough.  Definitely don’t let a tractor sit on the ramp for days in a pile of snow. Keep charging: during the day, during the night, whenever possible. Not only are you keeping the battery warm, you’re also keeping the specific gravity of the electrolyte high, mixing the electrolyte, and keeping the available power at a maximum. Plan ahead for next season: consider upgrading to chargers that either temperature compensate or provide a full finish regardless of temperature.