Nickel-Iron Batteries  Ni-Fe

NiFe Solar batteries from Radio Specialists Pty Ltd

Whatís wrong with lead acid batteries for solar applications?

Just about everything.

The biggest problem is that the very chemistry that stores the energy destroys the battery.

The lead acid battery has to sulphate when it discharges to work. The build up of sulphate on the lead plates destroys the battery.

So how much can it sulphate ?

Roughly 50% battery discharge without damage, or a voltage drop down to 12V at C/10 discharge (10 amps with a 100Ah battery).

Anything over this and your battery bank self destructs. 

Your 100Ah batteries just became 50Ah batteries otherwise you will destroy them.

Assuming you have plenty of sun, or other means to recharge them, they wonít sulphate too badly.

You could float charge them if you have a power source, but then that defeats the purpose, because you canít use the energy that you have stored, and itís then no longer a stand alone solar system anyway.

Bad weather, no sunlight, and they are now discharged to the point where sulphation has formed on the battery plates and you have wrecked your energy storage system.

The battery will never recover fully, and the battery life will be short.


Nickel Iron NiFe batteries are better.

Nickel Iron batteries have a different chemistry.

They don't use acid. They don't use lead.

They use alkaline and nickel and iron (which also makes them environmentally friendly) and they don't sulphate.

The voltage is higher than lead acid which makes them ideal for electronic equipment, being 13.5 volts no load fully charged, down to 12 volts when discharged.

For example a radio transmitter may require 10 amps on transmit, and may have 0.5 volts drop in the cable run.

A 12 volt lead acid battery will result in 11.5 volts at the radio, but a NiFe battery at 13.5 volts will result in 13 volts at the radio.

Even when the NiFe battery is discharged to 12 volts at 90% discharge you will still have 11.5 volts at the radio.

Likewise for other applications such as marine beacons you will still have good voltage at the beacon on long cable runs, because you had an extra volt to start with, 13.5 volts with NiFe instead of 12.5  volts with lead acid.

The plates in lead acid batteries self destruct when the lead literally falls apart over time resulting in sudden death. NiFe batteries do not have this problem.

Lead acid batteries in solar applications have a short life typically 3 years and sometimes as short as 12 months if constantly subjected to deep discharges where they sulphate badly.

NiFe batteries have 4000 discharge cycles or more which is more than 10 years of battery life and sometimes 20 years or more useable life.

NiFe batteries can be overcharged and undercharged, withstand deep discharge, withstand vibration, and large temperature ranges.

Why would anyone want lead acid batteries for solar when you can have NiFe.


For the doubting Thomases, for details of 85 year old Edison Nickel Iron Ni-Fe cells rejuvenated click here.



100Ah discharge curve:


Available sizes

20Ah 30Ah 40Ah 50Ah 60Ah 75Ah 100Ah 150Ah 200Ah 250Ah 300Ah 400Ah 500Ah


Nominal Voltage





Dimension(mm) Pole Weight(filled) (Kg) Electrolyte Volume (L) Container
L        W      H       
20 1.2 20 135 54 265 M10 1.9 0.6 PP
30 1.2 30 135 54 265 M10 2.4 0.6 PP
40 1.2 40 141 71 295 M10 3.6 1 PP
50 1.2 50 139 79 295 M10 5 1.3 ABS
60 1.2 60 139 79 295 M10 5.3 1.2 ABS
75 1.2 75 139 79 362 M16 6.5 1.7 ABS
100 1.2 100 164 104 345 M20◊1.5 9.3 1.8 ABS
150 1.2 150 167 162 345 M20◊1.5 12.5 2.7 ABS
200 1.2 200 167 162 345 M20◊1.5 13.5 2.7 ABS
250 1.2 250 282 170 348 M20◊1.5 22 5 ABS
300 1.2 300 282 170 348 M20◊1.5 26 6 ABS
400 1.2 400 285 172 490 M20◊1.5 34 8 ABS
500 1.2 500 285 172 490 M20◊1.5 36.5 8.5 ABS


Why would you want lead acid when you can have Solar NiFe