VRLA stands for Valve Regulated Lead Acid, which means that the batteries are sealed. Gas will escape through the safety valves only in case of overcharging or cell failure. VRLA batteries are maintenance free for life.
Sealed (VRLA) AGM Batteries:
AGM stands for Absorbent Glass Mat. In these batteries the electrolyte is absorbed into a glass-fibre mat between the plates by capillary action.
Because of the use of lead calcium grids and high purity materials, Victron VRLA batteries can be stored during long periods of time without recharge. Victron VRLA batteries can therefore be stored for up to a year without recharging, if kept under cool conditions.
Exceptional Deep Discharge Recovery:
Victron VRLA batteries have exceptional discharge recovery, even after deep or prolonged discharge.
Battery Discharging Characteristics:
The rated capacity of Victron AGM and Gel Deep Cycle batteries refers to 20 hour discharge, in other words: a discharge current of 0,05 C.
The rated capacity of Victron Tubular Plate Long Life batteries refers to 10 hours discharge.
Effect of temperature on service life:
High temperature has a very negative effect on service life.
Effect of temperature on capacity:
Capacity reduces sharply at low temperatures.
Cycle life of Victron batteries:
Batteries age due to discharging and recharging. The number of cycles depends on the depth of discharge.
Battery charging in case of cycle use: the 3-step charge curve:
The most common charge curve used to charge VRLA batteries in case of cyclic use is the 3-step charge curve, whereby a constant current phase (the bulk phase) is followed by two constant voltage phases (absorption and float).
Disadvantages of the traditional 3-step charge curve:
- During the bulk phase the current is kept at a constant and often high level, even after the gassing voltage (14,34V for a 12V battery) has been exceeded. This can lead to excessive gas pressure in the battery.
- Thereafter the absorption voltage is applied during a fixed period of time, irrespective of how deep the battery has been discharged previously.
- Research has shown that battery life can be increased by decreasing float voltage to an even lower level when the battery is not in use.
Battery charging: longer battery life with Victron 4-step adaptive charging:
Victron developed the adaptive charge curve. The 4-step adaptive chare curve is the result of years of research and testing.
The Victron four-step adaptive charge curve solves the 3 main problems of the 3-step curve:
Battery Safe Mode
- In order to prevent excessive gassing, Victron has invented the ‘Battery Safe Mode’. The Battery Safe Mode will limit the rate of voltage increase once the gassing voltage has been reached.
Variable absorption time
- Based on the duration of the bulk stage, the charger calculates how long the absorption time should be in order to fully charge the battery. If the bulk time is short, this means the battery was already charged and the resulting absorption time will also be short.
- If no discharge occurs during the next 24 hours, the voltage is reduced even further and the battery goes into storage mode.
Battery charging in case of standby use: constant voltage float charging:
When a battery is not frequently deeply discharged, a 2-step charge curve can be used. During the first phase the battery is charged with a limited current (the bulk phase).
Optimum charge voltage of Victron VRLA batteries:
The recommended charge voltage settings for a 12V battery.
Effect of temperature on charging voltage:
The recommended temperature compensation for Victron VRLA batteries is -4 mV / Cell (-24 mV /°C for a 12V battery).
The centre point for temperature compensation is 25°C / 70°F.
The charge current should preferably not exceed 0,2C (20A for a 100Ah battery).The temperature of a battery will increase by more than 10°C if the charge current exceeds 0,2C. Therefore temperature compensation is required if the charge current exceeds 0,2C.
|Victron 12V/38Ah AGM Deep Cycle Battery, 2 Year Warranty
|GTIN (Global Trade Item Number)
|Amp Hours (Ah)
|20 hr, discharge @ 25°C
|Cycle Life (DOD – 80% under controlled conditions)
|Charge voltage 'absorption'
|14.2 - 14.6 (Normal)
|Float Design life: 7-10 years @ 20°C
|197 x 165 x 170 mm (L x W x H)
|Net Weight (kg)
Victron Energy warrants its products to be free from defects in workmanship and materials for a period of: Batteries: 2 year limited warranty Li-ion batteries: 3 year limited warranty All other products: 5 -year limited warranty.
* Where allowed by applicable law and regulations, batteries must be shipped via Ground shipments only.