CHANGHONG NF-S Series Nickel-Iron batteries for solar PV application SICHUAN CHANGHONG BATTERY CO. , LTD.

Average annual ground solar energy(1983-2006) 7.5 3 Clear Sky Insolation Incident ,horizontal surface (kWh/m2/day) Sourece:NASA 2008

1.1 Introduction Nowadays, more and more The NF-S series Solar NiFe countries have attached Sichuan Changhong Battery environmental protection and advocate using green energy. Because of its high renewable energy applications reliability, long service life, under critical and harsh lower cost, pollution-free series battery has many Nickel-Iron(NiFe) batteries operation cost , low self- discharge, long cycling life, wide range of applications, environmental friendliness, renewable energy power discharge, wide temperature variations , mechanical & technical characteristics of Changhong Solar Nickel-...

features include a steel frame with welded plates, shock-resistant polypropylene or MBS casing material and special flame arresting fli p-top vent. In addition,the flooded electrolyte reserve is larger and prolongs the topping-up interval period. With the aid of advanced manufacturing methods and excellent design,the NF- S series Ni-Fe batteries are specially suitable for remote and isolated locations requiring minimal The power generated by solar photovoltaic power for the load on cloudy days and at night. systems is widely used for different applications: The normal solar photovoltaic system...

Navigation Aids Telecommunication Systems ◆ Radio Repeater Stations ◆ Emergency Telephone Posts Railway and Light Trains ◆ Emergency Lighting on Offshore Platforms ◆ Cathodic Protection for Pi pelines ◆ Electric Power Supply for Remote Areas/Islands 1.2.2 Components of the Photovoltaic System A photovoltaic system consists of three main parts: 1.Photovoltaic array 2.Electronic components, e.g. blocking diodes, logic circuits in power conditioners & controllers. Thus,the ideal photovoltaic power system is a reliable installation which requires infrequent maintenance. The batteries play a crucial...

component of the plate is steel, Changhong NF-S series NiFe cell consists of two groups weakened by repeated cycling, of plates, the positive plate which gives Changhong NF-S containing nickel hydroxide series NiFe batteries an exceptionally good cycle life. containing iron oxide. These Besides, the alkaline electrolyte active materials are retained inside doesn’t react with steel, in pockets formed from which means that the supporting nickel plated steel stri ps NiFe b a t teries stay inta c t and unchanged during their whole rolling process. These life. Since there is no corrosion, there is...

battery to be operated within a The electrolyte used in NF-S series NiFe battery is a combined ~60℃ , which makes the battery solution of potassium hydroxide and lithium hydroxide, which can improve the battery’performance, s (e.g. cycling life, energy efficiency, wide operational temperature range, etc) allowing it to reach the optimum level. The different s t a n dard concentrations of electrolyte allow NF-S series NiFe able to withstand very high temperature fluctuation that exists in some remote regions . batteries are fitted with special Nickel plated terminal poles made flame arresting...

1.5 Comparison Between VRLA and NF-S Series NiFe Cell 1.5.1 Table1 Characteristic comparison Sheet Item Name Lead Acid Battery Normal Voltage Floating Charge Voltage Temperature factor during floating charge Operating voltage Standard charge and discharge current High rate discharge performance Overcharge performance Over discharge performance Effect from floating charge voltage Poor Poor Extremely Poor When the charge voltage exceeds 2.35V/cell,the service life of VRLA cell will be reduced by 1/2 for every 0.1V/cell increase. 0.25C5A Good Good Good Operation life Storage life High temperature...

1.5.2 Cost Comparison Between VRLA and NiFe Cell cid d-A a Le Cost effectiveness There are three distinct parts to the cost of a battery system: ◆ Initial investment: including the cost of Replacement Preventive maintenance purchase,spares,tools,and installation. ◆ Maintenance cost: including unexpected and expensive downtime costs, Preventive maintenance Initial cost ◆ Replacement cost: including dismantling, shi pping,disposal and administrative costs Life-cycle Cost Comparison After Ten Years VRLA batteries: In the case of lead acid batteries,this can also include frequent replacement and...

1.6.4 Effect of temperature on performance The internal resistance of a cell Variations in ambient temperature affect the performance of a varies with the type of service and battery. The capacity de-rating factors which are required in the state of charge, thus it is sizing cell to compensate for temperature variations are given in difficult to define and measure it the following graphical form . accurately. The most practical the discharge voltage response to a change in discharge current. After fully charged at normal temperature, the NiFe cells are 50% discharged , the internal Available...

The Changhong NF-S series NiFe cell is adaptable to a wide range of depth of discharge (DOD). The number of cycles vary with DOD required. The lower DOD is, the more numbers of cycles are. The number of cycles reach thousands during shallow discharge, while it can only reach hundreds of cycles during deep discharge. The following figure gives the effect of DOD on the available cycle life. Typical cycle life versus DOD(20℃) Changhong NF-S series NiFe cell is designed for 20- year service temperature of electrolyte will reduce the expected life. In general , every 9℃ increase in temperature over...

gives typical water consumption values over different ranges of voltages and various temperatures. Surplus charge or overcharge The battery gives off no gas during discharge. The electrolysis of will break down the water of 1CC water generates 2000CC of mixture gas in the proportion of the electrolyte into oxygen and water should be added to compensate for water loss. In theory, the quantity of water consumed can be calculated according to the Faradic equation that each Ah of overcharge breaks down 0.366CC of water. However, due to the recombination separator used in Changhong NF-S series NiFe...