FAQ About Battery Chargers:
Why doesn’t my automatic charger charge my battery?
An automatic charger is designed to power the transformer when you first plug it into a receptacle. The automatic charger needs to “see” at least 4 volts in the battery to power up the circuitry. This initializes the charge sequence. When a completely discharged battery, or one with less than 4 volts charge remaining, is attached to the charger, the charger never “sees” this battery and will not begin the charging cycle. It will also cancel out the Engine Start function. The yellow charging light will also not come on. The meter (where used) will remain in the default “100%” position.
In order to get past this mode, you can “jump start” the battery so to speak, by momentarily connecting another fully charged battery in parallel. This will allow the charger to “see” a higher initial voltage enabling it to begin the charging sequence.
NOTE: Batteries that remain lower than 4 volts state of charge are often defective or just worn out. It is always best (safer) to check the battery with a hydrometer or Schumacher tester before charging.
The charger's green light is on, but I still cannot start my car - why?
In cold weather, a battery’s chemistry changes and gives the battery charger a false voltage signal. When this happens, remove the battery from the vehicle and move it to a warm location to warm up before charging. Never charge a frozen battery.
If the charger has a deep-cycle setting, try charging the battery for a short period of time at a higher, amperage charge rate. Then, try starting the vehicle again.
Why doesn't the green light stay on when my battery is completely charged?
1. The electronic control circuit board and LED lights use a minor amount of battery power to operate and to determine the battery’s state-of-charge. This results in the battery charger having to periodically charge the battery back to full charge. Consequently, the green light goes on and off as this process occurs.
2. All batteries have some internal power losses, which the charger is replenishing similar to #1.
3. The length of time that the green light is on is dependent on the battery type, its rated capacity, the degree of discharge, its age, and temperature.
Why don't I get sparks when I touch the battery clips together, creating a short?
With electronic short-circuit protection, the battery charger must be able to measure a battery’s voltage before it turns on. There is no output power in the clips until they are hooked up to a lead-acid battery. This is a built-in safety feature not found on most automotive battery chargers.
How long can I use the Engine Start/Cranking Assist on my charger?
The engine start/cranking assist feature on your charger is for short duration only (typically 3 to 5 seconds ON and 5 minutes OFF maximum). See the front panel of your charger for the recommended crank time your charger allows. Charge the battery for 15 minutes before using engine start/cranking assist. After 15 minutes of charging, set the selector switch to the Engine Start/Cranking Assist position. Then try to start the engine using the ignition switch.
If the engine fails to start within 3 to 5 seconds, stop cranking. Set the selector switch to a regular charge mode for another 10 to 15 minutes before trying to start the engine again. This rating is a UL standard based on the amperage output of the charger at 7.2 volts for 5 seconds. Recommended cranking assist cycles less then 5 seconds are in place to allow the charger to dissipate the heat generated by the increased power output through the transformer. Exceeding the recommended time duration of your charger’s cranking assist cycle can cause damage to the charger’s internal circuitry.
How long can I leave my charger connected to my battery?
The type of charger you are using more accurately determines this, but generally your battery charger is safe to leave powered up and connected to your battery until the battery has reached a full charge. Manual chargers should be removed as soon as the battery has reached a full charge. These chargers will not cycle or shut down by themselves. They will continue to put a current through the battery until they are disconnected. The use of a hydrometer or voltmeter to monitor state of charge is recommended for use with manual battery chargers.
Automatic chargers are more forgiving on your battery than manual chargers, but they are not designed for indefinite use. They will begin a cycling process, as described above, to prevent overcharging of the battery. Continued cycling will cause premature wear on the electromechanical parts of the charger, causing the charger to fail prematurely. The only charger recommended for extended or a storage application is the 1.5 amp 12-volt charger specifically designed for long term, slow trickle charging/maintenance applications.
Why can't I measure a voltage when connecting my volt meter to the battery clips?
No output power is supplied until the battery charger’s clips are hooked up to the battery. Then, it will measure and show the battery’s voltage.