What is a Trickle Charge?

A trickle charge, commonly associated with lead acid batteries, is a low-level electrical charge applied to a battery that roughly equals its rate of discharge. Trickle chargers can keep batteries topped off on secondary cars, motorcycles, RVs or boats that would normally become discharged due to infrequent use. A trickle charge device typically incorporates a float mechanism that prevents overcharging and can be left connected to a battery for indefinite periods of time.

Anyone with a second mode of transportation, recreational vehicle or boat knows the aggravation of going to use it only to find a dead battery. A standard charger can re-charge an undamaged battery in two to five hours, but this is a hassle. A jump start might work too, but none of these methods helps to reverse the negative effects that repeated discharging has on a battery. A new battery kept on a trickle charge when not in use will not only be ready to go at a moment’s notice, but batteries that go through fewer discharge cycles last longer, stretching your dollar.

During the course of a battery’s life, it will develop sulfation. Lead sulfate becomes crystallized on the surface of the lead plates inside the battery, preventing the battery from taking a full charge or operating at full capacity. The more often a battery fully discharges and sits in a discharged state, the worse the sulfation becomes until the battery can no longer hold a charge and needs replacement. If a sulfated battery sits long enough, the crystals grow to such an extent that they will eventually bow the battery case and finally crack it. Keeping a new battery healthy by feeding it a trickle charge greatly reduces the rate of sulfation, extending battery life.

There are various types of trickle charge products similar to the BatteryMINDer®, a popular brand. This small device plugs into an A/C wall outlet with a set of alligator clamps to attach to the battery terminals. Many trickle chargers also come with an optional attachment kit; a set of washers that slip over the terminal posts of the battery to stay permanently connected. A tail from the washers connects to the lead wire of the trickle charger making it easy to disconnect when ready to use the vehicle. Some trickle chargers are also marketed as conditioners, incorporating pulse-code technology to periodically clean lead plates of sulfation by using specific frequencies that dissolve the crystals.

A trickle charge uses very little electricity, but in some cases an A/C outlet isn’t handy or practical. For these situations you might consider a solar panel trickle charger. The solar panel is rectangular and can sit on the dashboard or wherever the most direct sunlight enters the vehicle. It plugs into a live cigarette lighter or auto power outlet to feed converted sunlight to the battery as an electrical charge. (If your cigarette lighter or power outlets require a key to work, the outlets are not live and the solar panel will not be able to use the outlet to charge the battery. The outlets must work without a key.) Solar panel chargers are also designed to prevent overcharging, but are not designed to charge dead batteries.