Not necessarily, the one I have is termed "Automatic" and it has an indicator LED and it switches to standbye and gives a visual indication that the battery is charged by the color of the LED.
The difference, between a trickle charger and a float charger, is the float charger has circuitry to prevent overcharging of the battery. It senses when you battery voltage is at maximum, and then shuts off the charge (floats voltage at zero, or near zero.)
A trickle charger does not have such circuitry. This will charge the battery no matter what the voltage level of the battery. If not disconnected, the electrolyte will boil out of the cells, or damage will occur to the plates.
A float charger can be left connected to the battery indefinitely, and will not cause damage to the battery.
If a charger has circuitry, that will stop the charging, when the battery voltage is maximum, it is a float charger.
Most rechargeable batteries, especially ni-cad and ni-MH, have a moderate rate of self discharge. For a battery backup system, you use a float charger so the batteries are always charged.
Jim
