Batteries | Victron Energy

Victron Energy Batteries for Photovoltaics - Gel and AGM in VRLA Technology

VRLA (Valve Regulated Lead Acid) means valve-regulated lead-acid batteries. Gas will be released through a safety valve in case of overcharge or cell damage. VRLA batteries are completely maintenance-free.

Maintenance-Free AGM Batteries (VRLA)

AGM (Absorbent Glass Mat) refers to batteries with absorbent glass mats. In maintenance-free AGM batteries, the electrolyte is absorbed by the fibers of the glass mat placed between the plates through capillary action. Compared to gel batteries, they are more suitable for delivering energy in a short time at high current intensity.

Maintenance-Free Gel Batteries (VRLA)

In this type of battery, the electrolyte is in gel form. The general advantage of maintenance-free gel batteries is a longer lifespan and higher cyclic capacity than AGM batteries.

Deep Discharge Batteries (VRLA)

Victron Energy VRLA batteries have an exceptional discharge tolerance, even after deep or prolonged discharge. It should be emphasized that repeated deep discharges and maintaining a discharged state for a long time

Low Self-Discharge of Gel and AGM Batteries

Thanks to the use of lead-calcium grids and high-purity materials, Victron Energy VRLA batteries can be stored for a long period without recharging. The self-discharge rate is less than 2% per month at 20°C. Self-discharge doubles for every 10°C increase in temperature. Therefore, Victron VRLA batteries can be stored for up to a year without recharging if kept in a cool environment.

Discharge Characteristics of Victron Energy Batteries

Deep discharge AGM batteries have excellent performance and are recommended for high-current applications, such as those in starter batteries. Gel batteries, on the other hand, have a long lifespan under both float and cyclic conditions.

Effect of Temperature on Charging Voltage

Charging voltage should be lowered with increasing temperature. Temperature compensation is required if the expected battery temperature for photovoltaics is below 10°C or above 30°C for an extended period. Recommended temperature compensation for Victron VRLA batteries is -4mV/cell (-24mV/°C for 12V batteries). The reference point for temperature compensation is 20°C.

Charging Current for Gel and AGM Batteries

The charging current for Victron Energy photovoltaic batteries should not exceed 0.2C (20 A for a 100 Ah battery). The battery temperature will rise by more than 10°C if the charging current exceeds 0.2C. Therefore, temperature compensation is required if the charging current exceeds 0.2C.