Specifications
11
FREQUENTLY ASKED QUESTIONS
Q. How do I know if the battery is charged?
A. The battery charger’s GREEN ‘FULLY CHARGED’ LED will illuminate to indicate when the battery
is fully charged. Alternatively use a Battery Hydrometer (Projecta Part No. BH100). A reading of
1.250 or more in each cell indicates a fully charged battery.
Q. Why does the battery charger have two ratings?
A. Battery chargers for automotive use have traditionally been given an RMS rating or peak rating
in the past. This rating is now used as an industry reference only.
Australian Standards now require all battery chargers to be rated at the charger’s
continuous output at 12.0 Volts, we express this as mA (milliamps) rather than A (Amps)
to avoid confusion.
Q. Why does the ‘FULLY CHARGED’ LED come on straight away?
A. There are three possible reasons why the ‘FULLY CHARGED’ LED may come on straight away.
1. The battery is fully charged.
2. The battery has taken a surface charge.
3. The battery has a faulty cell.
Q. What is Surface Charge?
A. Batteries unused or left flat for some time build up a resistance to being recharged. When the
charger is first connected, these batteries will take a surface charge, and the ‘FULLY CHARGED’
LED will illuminate within a short while. The battery however is not fully charged, the charger
is voltage sensitive and cannot differentiate between a surface charge and a fully charged
battery. After a few hours the battery may start to accept some charge but most batteries with
this condition will not recover.
Q. What is a Faulty Cell?
A. 12 Volt batteries contain 6 cells and one faulty cell is enough to ruin your battery. If after eight
hours of charging your battery is still flat, you should test the cells using a hydrometer. If one
reading is lower than the rest it indicates a faulty cell. It is pointless to continue charging, as the
battery needs replacing.
Q. I have connected the charger properly but the ‘Orange’ charging light does
not come on?
A. In some cases batteries can be flattened to the point where they have very little or no Voltage,
this is called a deep discharge. This can occur if a small amount of power is used for a long
time, for example a map reading light is left on for a week or more. Projecta automatic chargers
are designed to charge from as little as 3 Volts (except AC150 & AC250B which is 5 Volts).
If the battery is below this voltage the charger will not start charging, the battery may be
permanently damaged.