Will Charger Repair Sulfited Battery

A battery regenerator is a device that restores chapters to lead-acid batteries, extending their effective lifespan. They are too known as desulphators, reconditioners or pulse conditioning devices.^[one]

When batteries are stored in an uncharged country for an extended period, atomic number 82-sulfur deposits form and harden on the pb plates inside the battery. This causes what is known equally a "sulfated battery," which will no longer charge to its original chapters. Regenerators send pulses of electric current through the battery, which in some cases may cause the sulfate to bit off the plates and eventually dissolve.

Background [edit]

Conventional lead–acid batteries consist of a number of plates of lead and lead dioxide suspended in a jail cell filled with weak sulfuric acid. Pb oxide reacts with the sulfur and oxygen in the acid to requite upwardly an electron, leaving the plate positively charged and producing atomic number 82 sulfate. Lead reacts with the acid by taking in 2 electrons, leaving it negative while as well producing lead sulfate. The two chemical processes continue as long every bit an external circuit is available to permit the electrons to flow dorsum into the positive plates, only reaches equilibrium chop-chop when the battery is disconnected from the circuit. Each complete reaction produces virtually 2.11V. A typical 12V battery consists of six individual "cells" wired together in a single box, producing 12.66V when fully charged.

As a battery is discharged the density of pb sulfate in solution increases. In common designs, it reaches a critical density when discharged to about 75% depth of belch, or beneath.^[2] For example, a 12V bombardment with a 100 ampere hr (Ah) chapters will reach this density when 25 Ah (300 Wh) or more have been drawn from the battery. At this point, the lead sulfate will begin to precipitate out of solution onto the battery plates, forming a spongy picture show. If the bombardment is immediately recharged, the moving picture volition deliquesce back into the acid.^[2]

If the battery is stored or repeatedly operated in this partially charged country for an extended menstruation, the flick volition slowly crystallize into a solid. This process of "sulfation" takes fourth dimension, so information technology only has a chance to build to meaning levels if the battery is repeatedly discharged below this critical level. In that location are numerous other conditions that tin can lead to the same problem developing.^[3]

Batteries also have a modest amount of internal resistance that will discharge the battery even when it is disconnected. If a battery is left asunder, whatever internal charge will drain abroad slowly and somewhen reach the critical indicate. From and so on the film will develop and thicken. This is the reason batteries volition be found to charge poorly or not at all if left in storage for a long period of fourth dimension.

Chargers and sulfation [edit]

Conventional battery chargers use a i-, ii-, or iii-stage process to recharge the battery, with a switched-mode power supply including more than stages in order to fill the bombardment more rapidly and completely. Common to almost all chargers, including non-switched models, is the eye stage, normally known as "absorption". In this mode the charger holds a steady voltage slightly higher up that of a total battery, in order to push current into the cells. Every bit the battery fills, its internal voltage rises towards the stock-still voltage existence supplied to it, and the rate of current flow slows. Eventually the charger will plow off when the current drops beneath a pre-prepare threshold.^[4]

A sulfated bombardment has higher electric resistance than an unsulfated battery of identical construction. As related by Ohm'southward law, electric current is the ratio of voltage to resistance, so a sulfated bombardment volition have lower current flow. As the charging process continues, such a bombardment volition reach the charger'due south preset cut-off more rapidly, long before it has had time to accept a consummate accuse. In this case the battery charger indicates the accuse cycle is complete, but the battery really holds very trivial energy. To the user, it appears that the battery is dying.^[two]

Regeneration [edit]

The lead sulfate layer can be dissolved back into solution by applying much college voltages. Normally, running high voltage into a battery volition cause it to rapidly rut and potentially cause thermal runaway, which may cause information technology to explode. Some battery conditioners use brusk pulses of high voltage, besides short to cause significant current flow, but long enough to contrary the crystallization procedure.^[2]

Whatsoever metallic structure, such as a battery, will have some parasitic inductance and some parasitic capacitance. These will resonate with each other, and something the size of a battery volition ordinarily resonate at a few megahertz. This process is sometimes called "ringing". Even so, the electrochemical processes constitute in batteries have fourth dimension constants on the lodge of seconds and volition not exist affected past megahertz frequencies. There are some websites which advertise "battery desulfators" running at megahertz frequencies.^[2] ^[5]

Depending on the size of the battery, the desulfation process tin take from 48 hours to weeks to consummate. During this period the battery is as well trickle charged to go along reducing the amount of pb sulfur in solution. Commercial regenerators often support multiple batteries to provide parallel performance to improve throughput.^[ii]

References [edit]

^ Jamratnaw, Wuttibhat (2017). "Desulfation of lead-acid battery by high frequency pulse": 676–679. doi:x.1109/ECTICon.2017.8096328.
^ ^a ^b ^c ^d ^e ^f "Battery Desulfation", The Renewable Free energy Website
^ "Clarification and treatment of sulfated batteries"
^ "What are the iii Stages of Smart Chargers?", BatteryStuff
^ "Battery Desulfator"