These low maintenance Long life flooded tubular plate batteries have a cycling expectancy of up to 1500 cycles at 80% depth of discharge. The design life is D>20 years at 20°C, >10 years at 30°C, >5 years at 40°C. Under normal operating conditions and 20°C, distilled water has to be added every 2 – 3 years. The batteries are available filled with electrolyte or dry-charged (for long term stocking, container transport or air transport). Dry charged batteries have to be filled with diluted sulfuric acid (density 1,24kg/l @ 20°C). The electrolyte may be stronger for cold- or weaker for hot climates.