Baterías De Ni-Hierro

INTERBERG BATTERIES LTD.

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Nickel Iron Batteries

Technical Characteristics

This rechargeable battery was introduced in 1900 by Thomas Edison. It is a very robust battery which is tolerant of abuse and can have very long life even if so treated. It is often used in backup situations where it can be continuously charged and can last for 20 years. Also called Nickel Alkaline of NiFe batteries.

* Open circuit voltage is 1.4 V per cell and the nominal voltage is 1.20 V per cell

* Very robust.

* Withstands overcharge and over-discharge

*Accepts high depth of discharge - deep cycling.

* Can remain discharged for long periods without damage, whereas a Lead Acid battery needs to

be stored in a charged state.

* The ability of this system to survive frequent cycling is due to the low solubility of the reactants

in the electrolyte - potassium hydroxide.

* Lifetime of 30 years and more

* The low reactivity of the active components limits the high rate performance of the cells. They cells take a charge slowly, and give it up slowly. They are, therefore, ideal for applications with a very long (even during days) rate of discharge, like photovoltaic and other alternative energy systems.

* The Coulombic Efficiency is about 65%

Nickel-Iron batteries are robust and long lasting. They can be stored for very prolonged periods in a discharged state (even for many years) and then they can be recovered with an appropriate slow charging method.

In those cases where the battery has been stored for a quite long time in such a deep discharged state, it is advisable to halve the charging rate and charge them for at least twice the normal corresponding to the normal charging rate, taking regular voltage measurements, avoiding them to get too hot. Charging Current should be reduced if the temperature rises too much. And totally stop the charging if the temperature rise continues.

Once the charge has been completed, the battery shall stand cooling down for a while; then it will need to be subject to a gentle discharge at an equivalent of one tenth of the battery’s nominal capacity. This type of battery has been conceived and designed for low rate applications (slow discharge applications with prolonged backup times at a low discharge current). For High Discharge Currents it is advisable to use Pocket Plate NiCd batteries or Sintered Plate NiCd batteries for very high discharge current uses. In those case where the battery was hold on a discharged state for years, the charge-discharge process will have to be repeated a few times to restore the battery capacity and higher charge/discharge currents can be used in the subsequent charging-discharging cycles as the cells begin to recover.

After such a prolonged storage time (years) it might be necessary to top-up the cells with some distilled water, but be careful because overfilling can lead to more loss of electrolyte, as the electrolyte level will rise during the charging. It is advisable the electrolyte level to be situated on half the way between the maximum and minimum electrolyte level markings on the cell cases.

The Lifetime Battery

for Off-Grid Systemor On-Grid Back Up

No battery has outlasted the Nickel-Iron battery in daily use for home power systems!

There are records of Ni-Iron batteries still working at 100 % of their rated capacity after 60 years of operation !

The benefits of using Nickel-Iron batteries for energy storage:

• Longest battery life of any battery known today.

• Clean and simple.

• Time-tested (it was introduced to the market in the early 1900's).

• Battery efficiency stays about 80% throughout its lifetime.

• Does not sulfate.

• Does not freeze in any state of charge.

• Perfectly suitable for operation under extreme temperature and weather

conditions (very low and very high temperature resistant)

• Green technology.

• Easily rejuvenated by a simple electrolyte change.

• No need to do frequent equalization charges

• Very robust; withstands virtually any electrical or mechanical abuse

Frequently Asked Questions about the

Nickel Iron battery :

Q: When were nickel iron batteries invented and why?

A. The nickel-iron battery was invented in the early 1900's by Thomas Alva Edison (1847-1931). The US patent number is 827,297 and was filed on July21, 1904 and granted to the Edison Battery Storage Company on July 31, 1906. The battery was intended for use as the propulsion system for electric cars.

They were put on the market and then withdrawn because the battery did not perform as well as he wanted them to. After reintroducing them, the battery enjoyed a long outstanding life until 1972 at which time Exide Battery Corporation bought the Edison Battery Storage company.

Edison also believed in DC and "on site" power. That is, power transmitted very short distances from small DC generating plants located close to the electrical needs of the end user.

Q: How long will a nickel-iron battery last?

A: These batteries are a lot like a solar electric module. No one knows how long a PV module will last, but they have been working since the early 1950's when they became commercially available. The original batteries that were manufactured by Edison's company are still in use today in applications such as mines, railroads and home power systems. We have access to the coding that the company used and, therefore, by the markings on the top of the cell, we can determine the manufacture date and also the amp-hour capacity of the battery. Many of the original batteries are still in service after over 50 years! Some cells that were 50 years old still produce 100% of their rated capacity!

The new batteries that we have been importing from China since 1995 are still producing 100% of their rated capacity 16 years later. The manufacturer claims that their batteries will last up to 20 years with a regular discharge of 50% of the battery's rated capacity. Our guess is that they will last up to 40 years with a few electrolyte changes and less discharge. Electrolyte replacement is inexpensive when compared to battery replacement!

Q: Can they be used with the latest solar equipment?

A. YES! Almost all popular inverters built today like the Xantrex (Trace), Exceltech and Outback inverters

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