Previous
| Counter Pro Course Index |
Next
|
Counter Pro
|
||||||||||||||||||||||||
The work environment. |
|
Beyond the simple job of conducting enough electrons to the starter system, the battery cable has a tough environment in which to survive. At the end of the cable where it attaches to the starter solenoid, engine vibration tries to shake the lug loose from the cable. At the battery end, battery corrosion eats away at the terminal and wire where it enters the terminal.
Important: Don't let anyone tell you a sealed battery stops corrosion! Side terminal and sealed top terminal batteries do breathe through small weep holes and, in doing so, put a vapor of sulfuric acid on and around the battery! Side terminal batteries are as bad as top terminal batteries in this respect. However, they simply hide the problem over the edge of the battery top.
There is no way to prevent corrosion entirely. Using protective compounds and sprays helps delay or limit the corrosion. However, the life and effectiveness of the cable assembly can be lengthened with good design and construction practices at the manufacturing level.
Field repairs. |
|
| NOTE: The most popular of battery "fixes," the clamp-type battery connector (See Fig. 16.) must be considered a temporary solution. Corrosion attacks the conducting strands in short order, and effective mechanical and electrical contact will be lost. Frequent disassembly, cleaning, wire brushing, etc., can only be a stopgap to eventual replacement with a well-made OE configuration cable. |
|
| Fig. 16 | |
| A second method of making the connection between terminal and cable is called "crimping" or "staking". This is a typical shop technique of manufacturing a cable when a ready-made cable assembly is not available. Staking is not the preferred termination method, but it is an effective "local" solution when necessary. (See Fig. 17.) |
| Fig. 17 |
What makes the battery connection? |
|
The physical clamp contact between the battery post/plate and the terminal is all that makes the connection. Thus, the ability of the terminal to clamp tightly is critical. The tighter the physical bond, the more contact you get, and the less the path for corrosion to sneak under the clamping face.
(On the side terminal batteries you are limited by the 15-inch pound torque limit on the battery female terminals, of course. Over-torquing here can fail the battery terminal.)
Brass or lead-plated brass is a superior terminal connector in that it has superior conductivity to pure lead, and has much more strength than lead. A lead terminal without internal reinforcing, over-tightened by the installer, can be stretched to the point where it can no longer be tightened. When this occurs, the cable must be replaced.
Battery bolts. |
|
Professional design dictates the use of a square head bolt with a shoulder nut. This allows the
technician to tighten the nut on the bolt with one hand, and use the other hand to support the
cable and terminal, and protect the nut from the torquing action of the wrench. Cheaper designs
use a hex bolt, and don't use the shouldered nut design which permits accurate tightening torque
without damaging the terminal. (See Fig. 18)
Protecting the cable from corrosion. |
|
A properly made cable will minimize the possibility of corrosion creeping under the insulation
and attacking the conductor. A professional quality cable has a synthetic rubber or plastic
sleeve over the terminal and cable end to protect the cable/insulation gap at the connector.
(See Fig. 19)
Lug design: |
|
The strongest and most conductive battery terminal lugs are made from one-piece castings. Again, this permits a welded connection between the cable and terminal. Also, the one-piece design has more strength to prevent squeeze out from the starter terminal when the retaining nut puts clamping pressure on the lug.
Stamped tube lugs, however, are common in our business. They are cheap to make and appear useable. But, they typically have a weaker connection with the cable, lower electrical conductivity and less strength under the terminal nut. A loose or squeezed out terminal lug at the starter, or corrosion due to salty winter roads can make for bad electrical contact.
| Selling battery cables. |
|
The sale of a battery, starter motor or starter motor solenoid should be the signal for you to ask about the cable. Very frequently, the technician condemns the more technical or expensive item, and forgets that the problem may be in the cable.
Inspecting the cable at the battery end is often difficult since it may have good protection in the form of sleeves or closures. After cleaning up the connector, the cable may look okay, but still be corroded in the wires. There are three ways to check the wire:
1.) Bend the cable directly behind the connector to check for stiffness, an indication that corrosion has crept into the strands.
2.) Use an ohmmeter to check for excessive resistance. Battery cable should show no resistance.
3.) Crank the car. An engine in good condition, with a good battery, connections and starter should crank quickly and start easily. If you get slow cranking and very little amperage flow to the starter, resistance in the cable is the culprit. (Check for an aluminum or other inadequate cable, as well as corrosion.)
|
Booster cables. |
|
Booster cables share the same electrical demands as battery-starter cables. They need to flow a large volume of electrons at low voltage pressures. There are five differences in requirements between the two types of cable:
1.) Booster cables have a much shorter use time. They are supposed to work for a few seconds, rather than continuously. (The theory is that if the battery is in a poor state of charge, then the booster cables get the car started and charging. If the battery is in a good state of charge, and you are using the boosters to overpower a bad starter or engine, your solution is not the booster cables.)
2.) Booster cables, by the nature of their hook-up method, have a much less positive connection to the system.
3.) Booster cables need to be very flexible so they can be easily handled, routed and hooked up.
4.) The cables need to be long enough to reach from one car to another -- a very large distance for battery voltages.
5.) Booster cables can be of widely different quality levels within the above
performance framework. The level of workmanship and materials for a set of professional
quality cables used continuously in a shop setting is quite different than the level
required by a DIY car owner using cables once or twice each winter. (See Fig. 20)
