EL
BG
DE
ES
FR
ITGlossary · Batteries
Flooded Lead-Acid Battery
A battery with liquid electrolyte and vent caps that needs regular checks and topping up with deionised water.
Technical level:Intermediate
This is the oldest and simplest lead-acid technology. The plates sit in a liquid sulphuric acid solution and the gases produced during charging escape through the vent caps, so the water level slowly drops.
In large stationary installations such as data centres, telecoms and off-grid solar systems, it offers a long service life and a low cost per Ah. It does, however, need upright installation, good room ventilation, because hydrogen is released while charging, and periodic level checks.
Top up only with deionised or distilled water, never with acid, and do it after charging has finished so that the electrolyte does not overflow.
Related terms
- VRLA BatteryA sealed, valve-regulated lead-acid battery that never needs topping up with water and is used in most UPS systems.
- GEL BatteryA sealed lead-acid battery with its electrolyte in gel form, well suited to deep and repeated discharges.
- Noise (Electrical)Unwanted high-frequency disturbances on the supply voltage, e.g. from motors or power supplies, which UPS systems and line conditioners filter out.
- OPzS / OPzV Tubular BatteryStationary 2 V lead-acid cells with tubular positive plates, flooded (OPzS) or sealed with gel (OPzV), built for a very long life.
- AGM BatteryA sealed VRLA lead-acid battery whose electrolyte is absorbed in glass-fibre mat separators.
- Equalising ChargeA controlled charge at a higher than normal voltage that brings all cells of a lead-acid battery to the same state of charge.