A battery breakdown is bad news. If the battery can't supply enough amps to crank and start the engine, your customer's vehicle isn't going anywhere (except maybe downhill powered by gravity). A good battery is absolutely essential for reliable starting and for powering the vehicle's onboard electronics and electrical systems when demand exceeds the charging system's output.

A vehicle can be driven with a dead battery following a jump start as long as the charging system is functioning normally. But this is not recommended because it overloads the alternator and may damage the unit. The charging system is designed to maintain battery charge, not to recharge a battery that's lost all its juice. And if the battery is bad (it won't accept or hold a charge), no amount of charging will revive it. The only fix is to replace the old worn-out battery with a new one.

Automotive lead-acid batteries must be kept at or near full charge for optimum performance and longevity. When a battery runs down or becomes fully discharged, sulfate forms on the lead plates inside the battery. The layer of sulfate resists recharging and inhibits the battery's ability to accept and hold a charge. If the battery remains in a discharged condition for too long (more than a few days), or it is chronically undercharged because of a charging problem or because the vehicle isn't driven enough to fully recharge the battery, the battery may not fully...