You literally get what you pay for when buying booster cables. The primary quality and price determinants are gauge size followed by clamp type and overall cable capacity.
A great example of the range in prices for booster cables can be found at O’Reilly Auto Parts, which offers one of the widest selections on the market. A pair of 10-gauge O’Reilly cables (10 feet) costs $11. Next in price order comes an 8-gauge pair (12 feet) for $22, followed by a 6-gauge pair (12 feet) for $26, a 4-gauge pair (20 feet) for $36, a 2-gauge pair (20 feet) for $45, and a 1-gauge pair (25 feet) for $104.
So is the extra money for a pair of 1-gauge cables worth it?
That depends on the size of engine you’re trying to jump and the weather conditions you’re working in.
A pair of 10-gauge cables could jump a small car with a weak battery (as opposed to a completely dead one) if it were the middle of summer. But those same cables would fail to boost a large tractor with 24-volt batteries that are drained in the middle of winter. (For further information, see “Starting Power Requirements” on page 36.)
The bottom line is larger gauge cables have greater current capacity.
Electrical current, measured in amps, describes the number of electrons flowing through a circuit. Simply put, amperage is how much an engine is trying to suck through the wiring whether that be a battery cable or a pair of jumper cables.
So if you’re trying to jump a battery with 200-amp potential from a 200-amp booster battery using a pair of jumper cables with 80-amp capacity, bad things might happen.
High levels of current running through a small amount of conducting material may cause that material to heat up. And if the circuit is left running for too long, the conducting wire (and the insulation surrounding it) may be destroyed as a result of this heat.
Also bear in mind that engines consume direct current (DC), which becomes less efficient at conducting electricity (compared to alternating current) as a circuit (like jumper cables) grows longer. Therefore, shorter cables are more efficient at transferring power than a longer set, unless those cables are larger in diameter.