Technical Tips

Batteries

Technical tip - Understanding the battery function

The battery is a chemical storage facility for electricity for your vehicle. It is continually kept electrically filled by other components in your vehicle from the alternator or regulator. When you first experience difficult starting problems, consult your nearest Bosch Battery Power Station. They will ensure your battery is receiving a balanced feed of electricity from the alternator in order to store the amount you need for starting and to run the electrical system in your vehicle. Even when not experiencing problems, it is good motoring policy to have a free systems check at your local Bosch Battery Power Station. Pre-empt problems before holidays and the onslaught of cold weather when the battery is required to operate at peak performance.

Technical tip - Battery maintenance for cars

The battery is the first item to be blamed when the vehicle will not start. The service life of the battery depends to a large extent on many external factors which affect its performance. Most batteries fail due to various forms of abuse. Avoid the following common forms of abuse, and protect the battery and electrical system.

1. Loose battery terminals cause the melting of battery terminals and can result in sparks which lead to an explosion in the battery.
2. Vibration - holding clamps which are not properly fastened will result in the active material parting from the grid and the capacity will be reduced.
3. Over-tightening of the hold-down clamps will cause the container to crack or distort, causing damage to other parts of the vehicle.
4. Hammering on the battery terminal will loosen the poles or break the internal components. Always use the correct size spanners when replacing or removing terminals. Never loosen the terminals by force.
5. Dirt and damp on the battery will cause gradual self-discharge.
6. Overcharging - this causes an excessive loss of water and consequently causes the plates to shake off their active material, thus reducing capacity and service life.
7. A battery which is left standing in a discharged state will also suffer plate sulphation and irreversible damage.
8. A faulty regulator or alternator will lead to points 7 and 8 mentioned above.
9. A loose fanbelt leads to the discharge of the battery. Periodic attention to the battery as well as to the remainder of the electrical system, including the fanbelt tension, is essential for trouble-free service in any vehicle.
10. Incorrect electrolyte levels - when these are too low, plates dry out and sulphates. When these are too high, electrolyte escapes through the air hole, which can lead to acid damage.
11. Adding acid instead of water increases the PH of the electrolyte to the point where it attacks the plates.

Technical tip - Battery maintenance for caravans

When arriving back from that caravanning holiday, disconnect the caravan or auxiliary battery, put on trickle charge then store on cardboard or wood in a cool, dry place. Repeat this procedure every 2 - 3 months. Always have a hydrometer in the garage to check the relative density so you know the battery is fully-charged and ready for that impulsive, get-away weekend. Avoid long family faces when lights don’t come on and the car won’t start.

Technical tip - Upgrading

If you are unhappy with the battery life you get, and are satisfied the electrical system is in a good operating condition, consider upgrading. You (or a previous owner) may have modified the vehicle with airconditioning, extra lights, etc. Always ask when buying a replacement battery whether an upgrade is a viable option; it usually is, and will in general provide a longer battery life.

Lights

Foglamps - a wide beam penetrating below the fog

Driving lamps - a long, narrow beam which allows you to see further

Used in addition to standard headlamps, driving lamps improve safety and reducing fatigue; by extending the range of the main beam, they allow improved vision - increasing reaction time and helping you concentrate better. Bosch H4 halogen driving lamps will give you 400 - 600 metres of floodlight - or talk to us about converting your existing headlamps to H4 with our easy-to-install conversion kit.

Foglamps should be taken just as seriously as seatbelts - statistics show that fog is a major cause of accidents; even in locations where fog is not so frequently encountered, Bosch foglamps with halogen bulbs should also be part of your safety equipment - because where drivers are not accustomed to it, fog accounts for significant jumps in the accident rate.

Mounted about 40cm above the road, Bosch halogen foglamps allow you to see and be seen and throw out a wide beam which penetrates beneath the fog (where it is thinnest).

Foggy conditions - ordinary headlamps

Foggy conditions - Bosch halogen foglamps

The special lens aims the light to the sides in such a manner that you can clearly see the edge of the road, crash barriers and centre line at all times. It's as though a broad guiding beam of light were steering you safely through the fog so that you can keep your correct position on the road even in the thickest pea soup and be seen by the oncoming traffic.

• Driving and fog lamps - mounting positions.
• Driving lamps are most effective if mounted as high as possible.

Note on legal requirements for mounting backup and fog warning lamps:

Observe the legal requirements for the mounting and electrical connection of backup and fog warning lamps. Detailed instructions are enclosed with each pack.

Spark Plugs

How to Install Spark Plugs Correctly

Using a Torque Wrench

Correct installation of spark plugs with torque wrench - flat seat

Correct installation of spark plugs with torque wrench - conical seat

Tightening torques (N . m) 10 N . m ~ 1kpm
	In cast iron	In light alloy
M 10x1	10 ... 15	10 ... 15
M 12x1.25	15 ... 25	15 ... 25		In cast iron	In light alloy
M 14x1.25	20 ... 40	20 ... 30	2M 14x1.25	215 ... 25	210 ... 20
M 18x1.5	30 ... 45	30 ... 35	2M 18x1.5	220 ... 30	215 ... 23

Without Using a Torque Wrench

Screw in spark plug by hand until it is seated in the cylinder head. New spark plugs with flat seats are then screwed in by a further approx. 90º using the spark plug wrench, and spark plugs with conical seat as well as used spark plugs with flat seats are screwed in by a further approx. 15º.

Correct installation of spark plugs without torque wrench - flat seat

Correct installation of spark plugs without torque wrench - conical seat

With Bosch spark plugs, no greasing of the thread is necessary - the nickel-plated thread prevents corrosion and sticking of the spark plug in the aluminium cylinder head. This means particularly simple and time-saving installation.

Horns

Choosing a Horn

When choosing a horn (or hooter) for your vehicle, a distinction must be made between impact and fanfare horns; the differences are in the tone and pitch produced by these differently designed horns.

The impact horn produces a high-pitched which, because of its narrow sound wave, can travel a fairly long distance. This high-pitched tone can penetrate even the loudest of traffic noises and is therefore more suitable for highway use.

The fanfare horn, in contrast, produces a low-pitched tone, with a broad sound wave which travels more slowly and will not carry a great distance. This tone is melodious and better-suited to city driving where warning without shocking is the order of the day.