RE: charging sealed lead acid batteries

[Jeffrey Meade]

When a lead acid battery is manufactured, the acid and water are added and the battery is at full charge.  As a lead acid battery is discharged, the acid leaches into the lead and out of the water.  When a lead acid battery is charged, the acid is driven out of the lead and into the water.  Specific gravity cannot be checked when the lead acid battery is sealed.  An automobile alternator maintains a constant 13.6 VDC to 14.1 VDC depending upon the amperage capacity and quality of the vehicle charging system.  In an automobile charging system, the current reduces as the battery rapidly reaches optimal charge.  Starter current load rapidly reduces the automobile lead acid battery voltage, but the charging alternator rapidly raises the battery voltage.  This process is very good for an automobile lead acid battery.   Charging equipment that keeps a lead acid battery at a constant voltage for months on end and will damage the battery.  Some modern chargers raise and lower a lead acid battery by alternately charging and discharging the battery.    Equalizing charges take the battery to its fullest charge and keep the voltage at its maximum for a few hours longer than a regular charge.  Equalizing charges are best used sparingly.  Lead acid battery charger, 2   http://www.vtr.org/maintain/alternator-overview.html understanding alternators by Dan Masters, [EMAIL PROTECTED]   http://www.uoguelph.ca/ lead acid battery charger, 2, by Chaisaeng Euesakulkieat   To Fatcity.com from Jeffrey Meade, [EMAIL PROTECTED]           -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of Jeremy N. E. Proffitt Sent: Tuesday, December 03, 2002 6:33 PM To: Multiple recipients of list CHIPDIR-L Subject: charging sealed lead acid batteries   I would like to replace a pair of 6v lantern batteries in a lantern with a sealed lead acid or gel cell battery and would like to know about charging them.  I figure I can apply 12.5-13.5 volts DC though a wall transformer, do I need to add a current limiting resister or have I got this all wrong?   Thanks Jeremy