IMPORTANT INFORMATION ABOUT BATTERIES
How do you determine whether
a conventionnal battery or
AGM battery has been charged
After the battery has undergone charging (as per
battery manufacturer’s specifications), the following
caracteristics will tell you if a conventionnal or AGM
battery has been charged properly :
1-For conventional batteries, specific gravity of
the acid must be 1,265 or higher (4 balls or more
floating), or the terminal voltage must read 12.5
volts or higher.
2-For AGM (Absorbed Glass Mat, also referred
to as maintenance free) batteries, the terminal volt
age must read 12.8 volts or higher. (check with
Why do winter months seem to
bring more battery problems ?
The main reason is that the batteries have to
work so much harder in cold weather. Engine oil
is thick, so engine cranking effort is much higher.
Also a battery’s charging efficiency decreases in
cold temperatures. In addition, gasoline does not
vaporize as readily in the cold, which means that
even more battery cranking effort is required.
Sometimes a battery does not
hold a charge. Why ?
When a battery is in an excessively discharged
state, it does not readily accept a high current
charge. The battery may appear to be accepting
charge, but charging is occuring only at the surface
of the plates overheating the plates and destroying
the battery. In such a case, the battery must be
charged of a low current flow for an extended
period of time.
What is sulfation ?
Sulfation is the crystal formation of lead sulfate on
the battery plates or cells and one of the biggest
battery killers. This happens two ways:
1- When discharging continues uninterrupted, the
crystals grow and blossom into sulfation.
2- When the battery plates are exposed to air due
to low electrolyte level, the active lead material
oxidizes and sulfates. Once the plates have been
sulfated, the activity of the affected area is severely
impaired, and the battery will begin to lose life.
How should a battery be
Good battery maintenance should include
1- Always keep the acid level between LOWER and
UPPER lines on conventional batteries.
2- Never allow the battery to stand in a discharged
3- If necessary, charge the battery once a month
with Yuasa’s 12V Automatic Charger.
4- Keep battery clean, dry and free of dirt, Clean
battery terminals to prevent corrosion.
5- Inspect vent tube, ensuring that it is not bent,
twisted or clogged.
6- Check cables, terminals and case for obvious
damage or loose connections.
What is the normal charge rate
for a battery ?
Naturally, batteries of different capacities require
different charge rates. Generally a battery should
be charged at a slow rate of 1/10 its rated capacity
What is the purpose of the
battery exhaust vent tube ?
When a conventionnal battery is charged and
discharged, water contained in the electrolyte is
decomposed, generating hydrogen and oxygen
gases. These gases are vented out of the battery
through the exhaust vent tube to prevent potentially
damaging high pressure gas accumulation. Be
sure to remove sealed tube when installing a new
battery. AGM batteries (maintenance free batteries)
do not have an exhaust vent tube. They have a
built-in safety valve that ventgases.
What can cause a new battery
to fail soon after installation ?
If a new battery becomes unserviceable within a few
days or weeks, after its installation, it
may be due to one or more of the following
1- The battery has been activated incorrectly,
dissipating its strength from the outset.
2- The battery has been left too long without proper
initial charging or has been allowed to become
sulfated from disuse.
3- A faulty charging system
4- A short circuit in the electrical system.
5- Battery terminals become disconnected
6- Electrical capacity of the battery is insufficient for
size of the vehicle.
7- A blown fuse.
Why should you charge your
battery once a month?
When not in use, a battery discharges on a daily
basis sometimes up to 0.5 to 1%. This rate of
discharge increases when the climate is warm.
To make up for this loss from disuse, connect
your battery to Yuasa’s 12V automatic Charger
to maintain a constant float charge during the
extended time between uses.