Fronus 2.64kWh Tubular Battery 12V (Pro-Max 220Ah)

Note: This is a lead-acid battery, and its cycle life depends entirely on how deeply you discharge it. Fronus publish a curve rather than a single number, and the difference is large: roughly 6000 cycles at 20% depth of discharge, about 2850 at 50%, about 1350 at 80% and around 800 at 100%. That 80% figure is the one to compare against lithium, because that is the depth most lithium cycle claims are measured at - and Fronus's own Platinum lithium gives 6000 cycles at the same 80%, roughly four and a half times more. A lead-acid headline of "6000 cycles" is only true if you use a fifth of the battery. Tubular VRLA construction. Charging must be done in constant-voltage mode only, at 14.40-15.0 V for cycle use or 13.60-13.80 V standby, with temperature compensation of 0.005 V per cell per °C. Operating range -20°C to +45°C, and below 0°C the battery must be kept above 60% state of charge. Self-discharge under 3% a month at 20°C. Rated 220 Ah at the 20-hour rate; capacity falls at faster discharge - the 150 Ah unit delivers 150 Ah over 20 hours but only 105 Ah over 5. Boost charging starts at 22 A. Typical backup is 05:00 at 400 W. 63 kg. Two errors on the Fronus datasheet: both the 150 Ah and 220 Ah sheets print the same model code (FR-2204) and the same overall dimensions (502 x 191 x 397 mm), despite a 9 kg weight difference between them. The dimensions on at least one of the two are wrong, so they are not recorded here. Conforms to IS13369-1992.