User:Boooger11/desulfation

"Desulfation" is the process of reversing the process of sulfation that occurs to a lead-acid battery over time. Desulfation restores, at least partially, the ability of the battery to hold a charge over the life of the battery originally caused by sulfation (see Sulfation). Eventually this problem increases until the battery has lost a significant ability to perform properly.

Desulfation is one of the main ways to reverse some of the most difficult problems associated with sulfation. Desulfation is achieved by high current pulses produced between the terminals of the battery. This technique, also called pulse conditioning, breaks down the sulfate crystals that are formed on the battery plates.

It is a natural process that occurs in all lead acid batteries, but can occur significantly faster if placed in the wrong comination of temperature, poor charging, not used, etc.

Desulfation Techniques
Temperature affects both the desulfation and sulfation by increasing the rate of change for each. For instance, a warmer temperature battery will desulfate or sulfate more quickly. There are limits and too much heat can damage a battery (See Permanent Damage below).

555 timer, STAMP, and microcontrollers can be used to regulate the pulses of different widths and frequency of these high current pulses. These can also be used to automate the process since it takes a long period of time to desulfate a battery fully.

Short high current pulses tend to work the best.

Permanent Damage
A few unrecoverable battery symptoms include:


 * Loss of lead material on plates
 * Plates physically bent due to extreme temperatures and over charging

Recharged batteries which have a resting voltage under 8 Volts are highly suspect of being unrecoverable.

Symptoms
Batteries which have sat unused for long periods of time can be prime cadidates for desulfation. The long periods of no use allows the battery to sufer the process of sulfation. Some typical cases where lead acid batteries are not used frequently enough are planes, boats (esp sail boats), old cars, and home power systems with battery banks that are under utilized. Batteries with noticable sulfation might show signs of:
 * high internal resistance
 * low current supply

If possible a white coating on the plates can occasionally be seen (ie batteries with clear cases).

Power
(Needs to be revised) Trickle charger in parallel. Battery powered desulfators versus not battery powered. Diode to protect charger leads. Follow battery manufacturer instructions for charging. Some charging techniques can help prevent sulfation by equalization charging. This cycles through discharging and charging the battery regularly.

SLI vs Deep Cycle
SLI batteries (ie car batteries) have less dendriting because they are used more frequently vs deep cycle batteries. Deep cycle batteries tend to require more desulfation, can suffer from overcharging, and can be in a very large bank which leads to unequal charging and discharging.