Gunson G4104 User manual

BATTERY CHARGERS MODEL 1
Suitable for Lead/Acid batteries only
(Not suitable for non-rechargeable batteries)
INSTRUCTIONS FOR USE
BEFORE COMMENCING CHARGING
Itis advisable to disconnect the battery from the car or motorcycle circuits in order to
avoid any possibility of damage to the vehicle's electrical accessories.
Charging a batteryoften causes droplets of electrolyte to be ejected from the filler cap
holes. It is therefore better to remove the battery completely from the vehicle to avoid
any possibility of these splashes causing damage to bodywork or engine parts.
Remember that battery electrolyte is a corrosive acid which can burn the skin.
Take particular care to protect eyes. If splashes occur, rinse with plenty of cold water.
Battery charging should be carried out in a well ventilated location, since gasses are
released which are explosive, and which can build up in confined spaces.
Do not use the battery charger outdoors in the rain, since rain entering the charger
constitutes a safety hazard.
If the battery has cell filler caps (or a single large cap for all cells) then all the individual
caps or the single large capshould be removed or loosened before charging commences.
This allows any gases that are generated during the charging process to escape.
Remember to refit and/or re-tighten the cell filler caps when charging is complete.
With the cell filler caps removed, the level of the electrolyte should be inspected. If the
level of the electrolyte is below the level of the lead plates then the battery should be
topped up with distilled or de-ionized water before charging commences. Take care to not
overfill.
Add only enough water to reach to the top of the lead plates. Do not use tap water, which
maydamage the batteryand reduce its life. Suitable distilled or de-ionized water can be
obtained from your usual motor accessory supplier.
If the battery is of the "Maintenance Free" type, and has no cell filler caps, then refer to:
"CHARGING SEALED BATTERIES".
2. COMMENCING CHARGING
Ensurethat the charger is switched off at the mains. Then connect the positivelead of the
charger (coloured RED) to the battery positive terminal (usually indicated by + or P) and
the battery charger negative lead (coloured BLACK) to the negative terminal of the battery
(usuallyindicated by-or N). ON NO ACCOUNT CONNECT THE BATTERY CHARGER
TOTHE MAINS BEFORE CONNECTING THE LEADS TO THE BATTERY,
Connecting "live" leads to a batterysparks can be produced which on rare occasions can
ignite explosive gases in the battery cells. (Similarly, always switch off at the mains before
disconnecting the clips from the battery).
Ensure that the battery charger 6v/12v switch is switched to the correct position for the
battery being charged.
Connect the battery charger to the mains and switch on the mains.
The charger will now be charging the battery.
If a noticeable "click" sound is heardfrom the charger either immediatelyon switching on
the mains, or within a few seconds of switching on the mains, then this is an indication that
the automatic cut-out is being brought into operation due to an incorrect connection.
Should this occur, immediately check that the correct connections of the battery charger
have been made to the battery (i.e. red to plus, black to minus), and that the 6/12v switch is
in the correct position.
Anindication of the rate of charge can be obtained by connecting an ammeter (for instance
Gunson's AUTORANGER or TESTUNE in series with the charger. Turn off the charger at
the mains before connecting or disconnecting the ammeter, in order to avoid causing sparks.
3. DURATION OF CHARGING
Abattery should be charged until it is fully charged, since a battery left in a partially charged
or discharged state will slowly deteriorate.
On the other hand, a battery should not be excessively overcharged, since overcharging
causes a loss of the water of the electrolyte to the atmosphere in the form of gas. This
process is known as "gassing" and is the principal reason why a battery occasionally needs to
be topped up with distilled or de-ionized water. Particular care needs to be taken to not
overcharge a sealed or "maintenance free" battery, since no provision is made for
replenishment of the water in the electrolyte in this type of battery.
Gunson's Model 1 battery charger charges both 6 and 12 volt batteries at a maximum rate of
about one amp, which reduces as the battery nears full charge.
An approximate indication of the time needed to charge a reasonably new battery from the
discharged state is shown in the table below. (Note: the battery size in "Ampere Hours" is
usually marked on the battery).
Size 3 Ah Charge time 3hours
66
12 12
35 35
43 43
Less time will be needed if the battery is not reasonably new, or is not totally discharged.
The best way to measure whether a battery is fully charged is to use a measuring instrument
such as Gunson's TESTUNE or START-CHECK, or a hydrometer. These instruments are
available from any good motor accessory supplier.
It is useful to note that if a batteryis "gassing" then this is an indication that the batteryis at
or near full charge. Gassing will be noticed by the presence of bubbles occasionally rising in
the cells, often accompanied by a sulphurous smell. Battery charging should be discontinued if
"gassing" is evident.
During charging, the batterycharger mayoccasionally"cut out" for a few minutes (the user
may hear a "click" from the battery charger as the cutout disconnects or re-connects). This is
normal procedure, and is to guard against the battery charger overheating. The charger will
cut out moreoften in warm weather or if it is placed in a position with poor ventilation or if
the battery is very discharged.
The Cut-out is also a protection against the leads of the charger being inadvertently shorted
together, or connected to the battery with reversed polarity. In either of these events, the
cut-out will come into operation immediately. After a few seconds the cut-out will attempt
to re-makethe connection. Clearlythe user should avoid making such incorrect connections,
and should quickly switch off the charger if such incorrect connections arenoticed.
IF A "CLICK" SOUND IS HEARD FROM THE CHARGER WITHIN A FEW SECONDS OF
THE POWER BEING CONNECTED,THEN THE USER SHOULD EXAMINE THE
CONNECTIONS TO ENSURE THAT THE CHARGER HAS BEEN CORRECTLY
CONNECTED, AND THAT THE 6/12v SWITCH IS IN THE CORRECT POSITION.
4. AFTER CHARGING
When charging is complete, switch off the mains supply and unplug the charger before
disconnecting the charger leads from the battery. IT IS MOST IMPORT
ANT THAT THE
MAINS IS DISCONNECTED BEFORE THE CHARGER LEADS ARE
DISCONNECTED, since otherwise sparks may be caused which may ignite the explosive
mixture of gasses that may be given off during the charging process. Check the level of the
electrolyte in each cell of the battery, and top up if necessary, taking care to not overfill.
Electrolyte just sufficient to cover the plates of the battery is sufficient.
Replace the cell filler caps and tighten.
Wipe over the battery with a damp cloth to remove all traces of splashes of
battery electrolyte.
Re-install the battery in the vehicle, remembering to clamp the battery in the battery
compartment if such a clamp is provided.
Examine and clean the battery terminals and the battery lead clips (brushing with a wire
brush if necessary), and re-connect the battery lead clips to the battery terminals. Apply a
thin film of Vaseline or an aerosol type corrosion preventative to the connections, and re-
attach any protective boot covers to the battery terminals.
The user may wish to carry out a further check to ensure that the alternator of the vehicle
isoperating satisfactorily and maintaining the battery at full charge under normal running
conditions. Such a check is described under "NOTES ON BATTERY CARE".
5CHARGING SEALED BATTERIES
Some batteries, often called low maintenance batteries, or maintenance free batteries, have
cells which have no filler caps, and which are not intended to be topped up with water. It is
important that such batteries are not allowed to "gas" since this will reduce the level of
electrolyte in the cells, which can not be replenished.
It is known that "gassing" commences when the voltage at the terminals of the battery rises
above a level which is around 14.1 volts for a 12 volt battery, and 7.05 volts for a 6 volt
battery. Below this voltage there is negligible "gassing". It is therefore important with such
batteries that the voltage at the battery terminals is kept at or below this value.
Such batteries arepreferably charged with an "Automatic" or "Voltage Controlled" battery
charger. They can be charged with care using a normal battery charger, but this preferably
requires the use of an accurate voltmeter, such as Gunson's TESTUNE. Alternatively, for a 12
volt battery, Gun son's "StartCheck" can be used.
The method is to attach the voltmeter or the tester to the terminals of the battery, so that
the voltage at the terminals of the batterycan be monitored during the charging process.
Charging is continued while the voltage remains below 14.1 volts for a 12 volt battery (or
7.05 volts for a 6 volt battery), or the LED of START-CHECK is "out", but is discontinued as
soon as the battery terminal voltage reaches 14.1 volts (or the START-CHECK LED comes
"on"). The battery is then allowed to rest for a period of say 30 minutes, and charging re-
commenced. When the voltage again reaches 14.1 volts the charging is again discontinued,
and so on. Eventually, after several cycles of charging and resting, the battery voltage will rise
to 14.1 volts verysoon after the charger is switched on, and then the battery can be deemed
to be fully charged.
NOTES ON BATTERY CARE
1. INTRODUCTION
Essentially a battery is a unit for storing electricity. It acts as a reservoir for the electricity
produced by the alternator, evening out the bumps and troughs in the electrical supply, and
providing power for the various electrical systems of the car or motorcycle at times when
the engine is not running. However, the big job that the battery has to do is to supply the
massivesurge of electrical power that is required in order to drive the starter motor to turn
the engine. This is why, when a battery is beginning to fail, the first symptom is its inability to
start the engine.
Vehicle batteries work on the lead\acid principle, and are made up of a number of cells, each
with a nominal voltage of 2 volts, which are connected together internally to give a battery
with the required total voltage. A car battery comprises 6 cells, connected together to give
nominally 12 volts. 6-volt and 24-volt batteries would have 3 and 12 cells respectively.
Each cell consists of a number of positive plates interleaved with a number of negative plates,
the two types of plate being held in very close together, but separated by ceramic separators.
In a fully-charged battery (for instance when the battery is new), the positive plates are
formed from lead peroxide, the negative plates from a spongy form of lead, the whole
G4104

assembly of plates being immersed in dilute sulphuric acid, having a specific gravity of about
1.300 (i.e. being about 1.3 times as heavy as water).
When current is drawn from a battery (due, for instance, to the lights being switched on), the
lead peroxide and spongy lead both begin to change into lead sulphate, and the electrolyte
becomes more dilute. When the battery is fully discharged (i.e., is "flat"), both plates largely
consist of lead sulphate, and the liquid is very dilute, having a specific gravity of about 1.100.
Asabattery is recharged, the positive plate changes back to lead peroxide, the negative plate
to spongy lead, the sulphuric acid gets stronger, and eventually the state is reached where the
battery is fully charged.
Also as the battery is recharged, the voltage at the terminals of the battery increases. When
the voltage reaches around 14.1 volts for a 12 volt battery (7.05 volts for a 6 volt battery),
further charging then causes the effect known as "gassing", which is where the water in the
electrolyte is broken down into the gasses hydrogen and oxygen, which then bubble off, quite
vigorously if the charge rate is high.
This gas mixtureis explosive, which is why batteries should not be recharged in a confined
space or in the presence of naked lights, and why the mains should always be switched off
before connecting or disconnecting a battery charger to the mains so as to avoid the
production of sparks.
Virtually no gassing occurs at charging voltages below 14.1 volts, which is one reason why
alternator regulators are usually set at around this value. A battery can remain continuously
connected to a voltage of up to 14.1 volts without being overcharged in any way.
With many cycles of discharging and recharging, the plates are continually changing into lead
sulphate and back again, and occasionally particles will fall off and sink to the bottom of the
battery to form sludge. As the sludge builds up, there is less lead available for the chemical
processes, and the battery loses its capacity to carry charge. Batteries also deteriorate due
to an effect known as "sulphation", which is where a permanent form of lead sulphate forms
on the plates, shielding the plates from contact with the acid. Eventually these natural ageing
processes cause the battery to deteriorate to the stage where it is incapable of starting the
engine,and a new battery is required. The deterioration of a battery is often noticed in the
first cold snap of winter, because not only is the engine oil thick and the engine more difficult
to turn, but batteries having lower performance at low temperature.
Tomakebatteries last a long time they must be cared for. It is important that the alternator
voltage regulator is correctly set so that the battery is not overcharged. Vibration is bad for
batteries, and so are very "deep" discharges, and very high charging rates. Also, it is important
that batteries are kept fullycharged, and on no account must a battery be left for an
extended period in a discharged state, otherwise the dreaded "sulphation" will set in.
2. TESTING BATTERY CHARGE
The traditional wayis to use a hydrometer,but these can be a bit messy, and not everyone
has one. Of course with sealed batteries hydrometers are no use anyway. There is another
way, which is to make a very accurate measurement of the voltage at the battery terminals.
Gunson's TESTUNE, or a good quality digital voltmeter (DVM) is needed. For 12 volt
batteries, Gunson's START-CHECK can also be used.
There is one slight complication, which is that it takes batteries a long time to settle down to
astable voltage when they have been on charge, or when they have been used to provide
current. In fact, it takes longer for a battery to settle down when it has been on charge, than
when it has been used to provide current. To get an accurate measurement, it is best to wait
several hours, say overnight, with the battery totally disconnected. However, a reasonably
good indication of the state of charge of a battery can be obtained by carrying out the
following procedure: With the battery in the vehicle, and irrespective of whether the battery
has been on charge (or the engine running and the batterybeing charged by the alternator),
switch the headlamps on for 1 minute, then disconnect the battery and wait a further 15
minutes at least before making the measurement.
A fully charged battery should measure 12.65 to 12.9 volts or thereabouts. Part charged is
typically 12.15 to 12.65, and a flat battery is below 12.15. TESTUNE has coloured bands to
indicate these ranges. START-CHECK does the same thing by means of a LED (light emitting
diode) display,whereindividual LEDs areaccuratelyset to be illuminated at these voltages.
For a 6 volt battery, the voltages are exactly half those given above, i.e.: Fully charged 6.32 to
6.45 volts, part charged 6.07 volts to 6.32 volts, and flat below 6.07 volts.
Remember that as a battery ages it ceases to be able to carry a full charge, and this will be
reflected in the voltage measurement. Also remember that this test measures battery charge,
itdoes not say whether the battery is faulty: some faulty batteries can in fact carry a full
charge; you just can not get at it.
3. TESTING FOR FAULTY BATTERIES
Undoubtedly the best test of a faulty battery, a test so conclusive that you can be sure that
the battery is worn out, and that you are not wasting money by buying a new one, is to use
a"high current discharge meter". Unfortunately these are so expensive that only the trade
can afford them, although you often find one in a good quality car accessory shop for use by
the counter staff. To give your battery a fair test, make sure that it is fully charged before
taking it along to the professionals.
Another good way to test a battery, which gives a fairly good indication, is to test a battery
at what it is supposed to do, that is to crank the engine. Before carrying out this test it is
absolutely essential to test for voltage drops in the starter circuit (see section 4 below:
TESTING BATTERY TERMINALS). It is also essential that the battery is as fully charged
as it can be.
Having satisfied yourself that there are no other faults, the method then is to simply disable
the engine so that it can not start(for instance, by disconnecting the electrical supply from
the ignition coil, which is either + or - depending on the particular system), and crank the
engine on the starter, carefully measuring the time for which the starter is cranking briskly.
Eventually the battery will "die" and the cranking will become very laboured and might even
stop altogether. The change in cranking speed from brisk to laboured is usually quite sudden
and easy to identify. Both TESTUNE and START-CHECK have tests which give a visual
indication of the moment when a 12 volt battery is deemed to be flat. A good battery will
brisklycrank the engine for a minute and more, even in the coldest weather. If your battery
dies after a few seconds, it is a sure sign that it needs replacing.
One word of warning: starter motors are not designed for continuous cranking, so do not
carryon for morethan a minute or so without waiting for the motor to cool.
Another fault that batteries can have is that they can "self discharge" - a battery that appears
to be fully charged today can be flat tomorrow or the day after. It is easy to confuse this fault
with a fault in the circuits of the car - a glove compartment light that stays on all the time for
instance. To check whether a battery can hold charge it is necessary to test its charge over
aperiod of days using a hydrometer or good quality voltmeter. To check whether current
is leaking from the batteryto the car when everything is supposed to be switched off, it is
necessary to use an ammeter, or the "leakage current test" of TESTUNE, which accurately
measures leakage whether it is a few milliamps or a few amps. The TESTUNE scale has
coloured bands to show acceptable levels of "leakage" (e.g. due to a car clock, security system
or computer that are on all the time), and unacceptable levels (e.g. the light on in the boot).
4. TESTING BATTERY TERMINALS
When a vehicle will not start because the starter will not turn the engine quickly enough,
the problem may be dirty or corroded battery terminals. The same effect is caused by
faults such as a bad solenoid, loose or frayed earth straps etc, which may be tested in a
similar way.
The problem with battery terminals (and solenoid, earth straps etc) is that they have to
carry such a high current that even the minutest resistance, due to dirty deposits or
corrosion, can impede the flow of the current and prevent the car from starting.
The way to test for this fault is to measure the voltage drop across the component while
the engine is being cranked on the starter. For example, to check battery terminals hold
one meter probe on the terminal that fits on to the battery post and hold the other
probe right on the terminal post itself. Then the engine should then be cranked on the
starter, having first prevented the engine from starting by disconnecting the + or - lead
from the coil. If the terminal is making good contact then the voltage drop will be zero
even measured on a 0 - 1 volt scale. A reading of 0.25 volts is a bit worrying, and 0.5 volts
is an indication of a definite fault (halvethe se voltages for a 6 volt vehicle). Gunson's
TESTUNE has a suitable voltage scale with coloured bands to indicate good and bad
battery terminals, solenoid, earth straps etc.
5. TESTING ALTERNATORS
Afaulty alternator will eventually result in damage to the battery, either through
undercharging or overcharging.
The way to test an alternator is to use a voltmeter connected directly across the terminals of
the battery while the engine is running, but be sure to start with the battery in a reasonable
state of charge.
If the alternator is working correctly, the voltage across the terminals of the battery will
normally be within the range 13.5 - 14.1 volts (half this for a 6 volt battery). This is the
voltage that the alternator provides to keep the battery fully charged but not overcharged.
However, it should be noted that some vehicle manufacturers specify a rather higher voltage
for the alternator regulator, and reference should be made to the workshop manual for the
exact recommended voltage for a particular vehicle.
Analternator should be able to hold this voltage at the battery terminals at all speeds above
idle (as soon as the ignition warning light goes out), and the reading should be approximately
the same irrespective of any electrical equipment that is switched on, such as headlamps,
windscreen wiper motor etc.
If the voltage reading is too low, or falls too low when equipment is switched on (e.g.
headlamps), then the alternator is undercharging.
If the voltage is too high, or rises too high when the engine speed is increased (with or
without the headlamps on), then the alternator is overcharging.
Although any good quality voltmeter should be capable of carrying out this test, the Gunson
TESTUNE has been designed particularly to make this test easy. It has an offset scale (one
that does not start at zero, in fact it starts at 12v, and only measures voltages in the range 12v
to 17v) to give a scale that is greatly expanded to be accurate and easy to read at the
appropriate voltages for alternator tests. It also has coloured bands to show when an
alternator is OK, or when it is undercharging or overcharging.
TECHNICAL SPECIFICATIONS
INPUT
MODEL 1 230V AC 50Hz 15 W
OUTPUT
6V 1.5A RMS(EFF) 1.0A DC(ARITH) CONTINUOUS
12V 1.2A RMS(EFF) 0.8A DC(ARITH) CONTINUOUS
RECOMMENDED MINIMUM BATTERY CAPACITY: 6Ah
FULL OVERLOAD PROTECTION
REVERSE POLARITY PROTECTION
THERMAL CUTOUT PROTECTION
CONFORMS TO BS 3456
DOUBLE INSULATED
GUARANTEE
This guarantee is additional to the purchaser's statutory rights.
The Tool Connection has made every effort to ensure that this BATTERY CHARGER
is of the highest quality.
If this BATTERY CHARGER should need service or repair, it should be returned direct to
The Tool Connection Limited,
Kineton Road, Southam,
Warwickshire CV47 0DR
T
el:T
echnical Service Department ++44 (0)1926 818181
When goods arereturned for service or repair, full details of faults requiring attention
should be given, and also date of purchase.