Iota Technical Paper - Charging Lead Acid Batteries for Long Life

Two common maintenance practices that contribute to
sulfation are storing batteries in an uncharged condi-
tion and undercharging. Both of these conditions can be
prevented by using smart charging technology to safely
maintain stored batteries at full charge.
Gassing, Overcharging and Water Loss
A careful margin exists between maintaining a battery’s
full charge and overcharging. Like undercharging, over-
charging reduces battery life, but it can also lead to a
potentially dangerous situation. Preventing overcharging
is another important control an owner has over battery
life and safety.
One of the hazards of overcharging is excessive gassing. Some gassing
naturally occurs during normal charging, but when a lead acid battery is
overcharged, the electrolyte solution can overheat, causing hydrogen and
oxygen gasses to form, increasing pressure inside the battery. Unsealed
flooded lead acid batteries use venting technology to relieve the pressure
and recirculate gas to the battery. Gassing in excess of venting capacity or
malfunctioning vents can ‘boil’ the water out of the battery and the resulting
water loss can destroy the battery. If the electrolyte solution falls below the
level required to reach the charge plates, the exposed charge plates will
sustain damage. The most hazardous situation is when a lead acid battery is
overcharging and overheating, producing more combustible hydrogen and
oxygen than can be vented, when finally the pressure is relieved – instantly
– by explosion.
Good management practices in battery maintenance can prevent excessive
gassing and damage due to water loss. First, the battery should not be over-
charged. This can be prevented with smart charging technology that auto-
mates multi-stage charging. Second, the water level in the battery should be
checked according to the manufacturer’s specifications.
Correct Charging Matters
How a lead acid battery is charged can greatly improve battery per-
formance and lifespan. To support this, battery charging technology has
evolved with smart chargers which assist owners by taking the guesswork out
of correctly applying the various stages and voltages of charging. Correct
application of the charging stages will maintain a battery at full charge,
balance undercharging and overcharging, and help prevent sulfation and
excessive gassing.
Effective and Safe Multi-Stage Charging
Multi-stage charging is the safest and most effective method of charging
flooded lead acid batteries. The electrolyte solution has phases of accept-
ing a full and complete charge – multi-stage charging accommodates those
phases and helps to prevent sulfation and excessive gassing. The first three
stages are bulk, absorption, and float.
Charging Stored Batteries for Long Battery Life
IOTA ENGINEERING
Negative and
positive battery
plates damaged
by sulfation.
Evaporation of water due to excessive
overcharging can result in cracked or
exploding batteries.
2