You should not leave a lead acid battery on a charger for long periods. Charge it only when it reaches a fully discharged state, around 80% Depth of Discharge.
Important: With lead-acid batteries, the formation of explosive hydrogen and de-gassing must be expected during charging. In extreme cases, a high concentration of hydrogen may result in an explosion with serious injuries and damage. Defects of the battery should also be noted. Acid may leak from damaged batteries.
Power Sonic recommends you select a charger designed for the chemistry of your battery. This means we recommend using a sealed lead acid battery charger, like the the A-C series of SLA chargers from Power Sonic, when charging a sealed lead acid battery. Sealed lead acid batteries may be charged by using any of the following charging techniques:
The most important first step in charging a lead-acid battery is selecting the correct charger. Lead-acid batteries come in different types, including flooded (wet), absorbed glass mat (AGM), and gel batteries. Each type has specific charging requirements regarding voltage and current levels.
Are lead acid batteries safe?
REMEMBER – SAFETY FIRST!! Lead Acid Batteries that are being charged except sealed (AGM and Gel) generate very flammable and explosive gasses ensure that no flammable materials are nearby and ensure no sparking occurs. Chargers MUST be turned off during connecting or disconnecting leads.
IMPORTANT – Ensure the correct PPE is used whenever handling, using or charging Lead Acid Batteries. Staff that perform battery charging or testing MUST have completed the charging and safety training and have undertaken the competency test. (Ref Federal Batteries charging and safety procedures document). Why is charging correctly so important?
Battery acid is only used when the battery is first filled. Sealed batteries (AGM AND Gel) are sealed at the top, and thus won't leak acid when tipped over or give off gas while charging under normal conditions. Note some Sealed "Maintenance Free" types still use wet electrolyte, but simply have a sealed top.