Fronius Reserva battery module 3.15kWh3.15kWh 102.4V LFP module for the Fronius Reserva high-voltage battery

Overview

The Reserva module (item 4,240,370) is the 3.15kWh, 102.4V building block of the Fronius Reserva high-voltage battery. Two to five modules stack on a Reserva base under a Reserva BMS, giving 6.31 to 15.79kWh usable per tower at 204.8–512V; BMS and base are separate items. Each module weighs 33.5kg and measures 250×772×176mm. Use it to build a new tower or to extend an existing one following the service-mode procedure in the manual, keeping the same module count in every parallel tower.

• 3.15kWh, 102.4V LFP modules, 2–5 per tower
• 6.31–15.79kWh usable per tower, up to 4 towers
• Max. 32A output current, 95% battery efficiency
• 6,000 cycles to 60% state of health
• IP65, indoor or protected outdoor installation
• 10-year warranty, RS485 link to the inverter

How it works

Fronius Reserva is a stackable high-voltage battery coupled on the DC side of a Fronius hybrid inverter, so solar energy is stored without an extra AC conversion. Each tower consists of a base, two to five 3.15kWh modules and a battery management system on top, giving 6.31, 9.47, 12.63 or 15.79kWh usable at 204.8–512V nominal. Up to four towers with the same number of modules can run in parallel.

The BMS protects the lithium iron phosphate pouch cells against over- and undervoltage, overcurrent, temperature and cell faults, and calibrates the state of charge every two months or 50 cycles. After a system shutdown the battery can supply energy for a manual dark start, after which the inverter enters backup mode. Firmware updates run through the inverter's user interface.

Key features

Maximum output current is 32A per installation, independent of the number of towers, giving charge and discharge power of 6.55kW (6.3kWh) up to 16.38kW (15.8kWh), depending on temperature, state of charge and inverter. Battery efficiency is 95% at 0.2C, and Fronius states 6,000 cycles at 0.5C to 60% state of health. The housing is rated IP65 and convection-cooled.

Installation and compatibility

Reserva is approved with the Primo GEN24 Plus (2–3 modules), Primo GEN24 Plus SC (2–4 modules), Symo GEN24 Plus and Plus SC and Verto Plus (2–5 modules). Install indoors or in protected outdoor areas at -20 to +55°C and up to 2,000m, on a load-bearing, non-flammable wall, with 300mm recommended on each side. DC cables to the inverter may be up to 30m, using Stäubli MC4-Evo stor connectors.

Monitoring and settings

Operating data reach the inverter over RS485 and appear in Fronius Solar.web, while the LED status indicator on the battery shows the state of charge. The battery is added in the inverter's user interface during commissioning. When extending a tower, the existing modules are brought to a defined state of charge in service mode before new modules are fitted.

Questions and answers