Battery Maintenance & Care

The most common problem is sulfation due to leaving a battery in an undercharge condition. While this does not 'kill' the battery immediately it decreases the charge capacity of the battery. If the sulfate is allowed to get to third stage crystaline sulfate the process is no longer reversible through normal charging.

Auto start batteries are not made to be discharge below 10.5 volts. If this happens the lead sulfate formed on discharge will expand across the plates and separators and short the battery. The voltage across the terminals will measure 10.5 volts. This battery is dead and is not restorable. Read more

Why Batteries Die

When the active material in the plates can no longer sustain a discharge current, a battery "dies". Normally a car (or starting) battery "ages" as the active positive plate material sheds (or flakes off) due to the normal expansion and contraction that occurs during the discharge and charge cycles. This causes a loss of plate capacity and a brown sediment, called sludge or "mud," that builds up in the bottom of the case and can short the plates of a cell out. This will kill the battery as soon as the short occurs. In hot climates, additional causes of failure are positive grid growth, positive grid metal corrosion, negative grid shrinkage, buckling of plates, or loss of water. Deep discharges, heat, vibration, fast charging, and overcharging all accelerate the "aging" process. Approximately 50% of premature car battery failures is caused by the loss of water for normal recharging charging due to the lack of maintenance, evaporation from high under hood heat, or overcharging. Positive grid growth and undercharging causing sulfation also cause premature failures.? Read more

How Batteries Sulfate

A battery tends to be discharging for much longer periods of time than when it is being charged. After all, a car sits for longer periods of time than when it is being driven. Hence, lead sulfate is produced faster than it can be reverted into lead, lead dioxide, and water (see equations below).

When the lead sulfate is left sitting for long periods of time, the initially spongy lead sulfate hardens and forms crystals. Unlike the spongy lead sulfate, these crystals cannot be reverted back to active material (lead and lead dioxide). More crystals on lead plates mean less active material is left to be used for the battery's chemical reaction. A battery is effectively dead when there is simply not enough active material left to start a vehicle! Read more

Reviving Dead Batteries

As long as there is still active material in the battery and the plates aren't shorted, any battery that fails due to lead sulfate crystallization has a chance of being revived and reused. This is not only limited to car batteries, but to ALL lead acid batteries! There are already battery clinics in New Zealand now that revive and recondition batteries, which are later sold back to customers at about 1/3 the retail value of a new battery. These batteries are given 6 month replacement warranties!

The graph below shows a typical revival process of a 45 Ah Ca-Ca battery that had failed 2 years ago due to shelf sulfation. Note how the impedance and CCA (Cold Cranking Amperes) are inversely related. The CCA of the battery, initially at 112 increased gradually up to 321. The battery was originally rated at 360 CCA, and it takes about 180 CCA to crank a car. Read more

Why not desulphator additives?

• EDTA usually comes in powder form, or as a solution. With manufacturers tending to favour sealed maintenance-free type batteries, there is no chance to introduce EDTA to the battery in the first place.
• EDTA works by forming a complex compound with the lead sulfate layer on the plates. While this removes the insulating layer, the active material that had formed lead sulfate will not be reconverted once the battery is charged. In principle, the insulating layer of lead sulfate is removed, but active material is sacrificed in the process. Read more