Nowadays, more and more people have realized the importance of environment protection and are actively advocated green energy. Because of its long service life, high reliability, lower cost, environmental friendliness and other characteristics, Nickel Iron (Ni-Fe) batteries are gradually replacing the lead-acid batteries in a wide range of applications, especially for solar PV and renewable energy power systems. 

This manual details the technical characteristics of EverExceed Solar Nickel-Iron EVTN series battery. 

The EVTN series Solar NiFe batteries manufactured by EverExceed Corporation are specially designed for solar PV and renewable energy applications. It has long cycling life, low operation cost, environmental friendliness (no lead, cadmium, or acid and is highly recyclable), high safety with almost no possibility of burning or thermal runway, etc. It can 

withstand deep discharge, wide temperature variations, mechanical & electrical abuses, and still show excellent and reliable performance over a long period of time. 

The EVTN series solar NiFe batteries are suitable for all solar photovoltaic power systems.They are widely used as storage power supply for solar photovoltaic systems, commercial and residential buildings, offshore oil platforms, railway transportation, crossing guards lighting, signaling, isolated BTS station, cathodic protection for pipelines and radio navigation systems. EVTN series solar Ni-Fe batteries can last longer than 30 years if they are operated with the recommended practice. Special features include a steel frame with welded plates, shock-resistant polypropylene or

MBS casing material and special flame arresting flip-top vent. In addition, the generous electrolyte reserved prolongs the
topping-up interval period. With the aid of advanced manufacturing methods and excellent design, the EVTN series Ni-Fe batteries are especially suitable for remote and isolated locations requiring minimal maintenance.

• Long cycle life (maximum service life can reach 30 years or more, if operated correctly)
• Environmental friendliness (no lead, cadmium, or acid. highly recyclable)
• High safety with little possibility of burning or thermal runaway
• Wide operating temperature range
• Low maintenance
• With its generous electrolyte reserve, the topping-up frequency is reduced so the EverExceed EVTN series
• NiFe battery can be left in remote sites without maintenance for long periods of time.
• High resistance to mechanical and electrical abuse
• Low transportation and installation cost
• Because of its high mechanical strength, EVTN series
• NiFe battery is able to withstand harsh treatment during transportation and installation.

Rated Capacity
The capacity of the EverExceed EVTN series NiFe battery is rated in ampere hours( Ah), which is the quantity of electricity
discharged by 5-hour discharge rate (C5) current to 1.0Vend voltage at 20℃ after being fully charged.

Nominal Voltage
The nominal voltage of the EverExceed EVTN series NiFe battery is 1.2V/cell

Effect of Temperature on Performance
Variations in ambient temperature affect the performance of a battery. The capacity de-rating factors, which are required in
sizing cell to compensate for temperature variations, are given in the following figure.

Short Circuit Current
The short circuit current of EverExceed EVTN series NiFe cell is approximately 10 times of the ampere-hour capacity.

Open Circuit Loss
Because of self-discharge, the state of charge in the open circuit state will decrease slowly with time. The open circuit loss
value at different temperatures, which may be experienced in photovoltaic application, is shown in the following figure.

Cycling
The EverExceed EVTN series NiFe cell is adaptable to a wide range of depth of discharge (DOD). The number of cycles varies
with DOD required. The lower the DOD is, the higher the cycle number. The numbers of cycles reach thousands in shallow
discharge applications, while it can only reach hundreds of cycles during deep discharge. The following figure shows the effect
of DOD on the available cycle life.