Confusion abounds about trickle chargers: what they are, how they work and how to use them. Some people believe that a battery can be left on a trickle charger for an indefinite period of time while others believe they should only be used long enough to charge the battery. This confusion results from a misunderstanding between two different types of chargers: Trickle and Float. Both work similarly, but should be used differently.
Using Trickle Charger
A trickle charger works by charging your battery at a rate similar to the rate at which it discharges. However, it is possible to cause damage to your battery by leaving it on the charger for too long. While a trickle charger works at a much slower rate than a regular battery charger, they are not designed to be left on a battery indefinitely. Depending on how depleted your battery's charge is, you may need to leave it on the trickle charger for a few hours or for a day or two. It is important to monitor the battery while it is on the charger and remove it immediately upon receiving a full charge. Otherwise, the battery could be ruined or even catch fire.
A good use for a trickle battery charger is for a battery that has not been in use for several months as it is better for a battery to be recharged at a slow rate.
Using Float Charger
A float charger works much in the same way as a trickle charger--by delivering a slow charge to the battery. However, the float charger is designed to prevent overcharging of a battery. It can sense when the battery has received a full charge and thus ceases charging until the battery begins to lose its charge. When it senses a loss in charge it will automatically resume charging. Due to this feature, the float charger can be left on a battery indefinitely.
A good use for a float charger is for a vehicle that is rarely driven, but that the owner wants to be able to access at any time without having to recharge the battery.
How to Use Trickle And Float Chargers
It is important to know how to connect a charger to a battery to prevent damage and injury. There should be a black clip and a red clip on the charger. These are what you use to connect to the battery. The red goes on the positive terminal, usually marked with a plus (+) sign and the black goes on the negative terminal, usually marked with a minus (-) sign. It is recommended to connect the back first and then the red. Once the wires have been connected to the battery, plug in the charger then turn it on.