02/06/2023
Good day Armu Family
This is very interesting as we all basically in the same boat with loadshedding issues
Hope this might bring a bit of clearity
The security industry has for a long time adopted the Sealed Lead Acid Battery as the standard for backup power to alarm panels.
The 12V 7AH Sealed Lead Acid or Gel batteries are the most commonly used on alarm panel installations. They have unfortunately run into a problem called..... Eskom.
Under stage 6 rolling blackouts, some areas spend 10 hours a day without electricity. Every time the battery is discharged when the power is turned off, it loses a part of its capacity.
In some alarm installations, the battery is fully discharged, and never returns to its original capacity. A battery which was lasting the SAIDSA recommended 6 hours, now starts lasting 5 hours, 4 hours, 3 hours …. , and the entire alarm installation may turn off during a power outage.
How much capacity the battery loses depends on:
The quality of the battery
The quality of the charger
The current consumed by the alarm installation
Whether the alarm panel cuts-out at a certain point to preserve the battery life
Lead acid batteries also do not like the high temperatures in our roofs in the African sun.
ENTER THE LITHIUM-ION BATTERY
There is a replacement for the standard lead acid battery in the same size and
capacity.The standard replacement is called a Lithium iron phosphate (LifePO4). It can endure thousands of charge and discharge cycles before losing its capacity.
> Isn’t it dangerous?
LiFePO4 are the safest type of lithium battery because they are not prone to overheating and even if they're punctured, they won't catch on fire.
> Isn’t it environmentally hazardous?
The cathode material is also non-hazardous and therefore it poses no environmental or negative health hazards.
> What are the pitfalls?
It costs more - as simple as that.
THERE ARE SOME ISSUES WITH DIRECTLY REPLACING A LEAD-ACID WITH A LITHIUM-ION BATTERY
> The charger:
Lithium-Ion batteries require a higher charge voltage than lead acid to obtain their full capacity (typically 14.6V as opposed to 13.7V)
> Low Battery Measurement:
The alarm panel will report a low battery condition when the battery reaches a certain voltage.The SAIDSA minimum voltage is 10.2V, but this differs from one alarm panel to another. Normally it is slightly higher. The voltage of the Lead Acid battery degrades as it is discharged.
The Lithium-Ion voltage falls over a cliff when it is discharged. One must be careful that the panel will report a low battery condition before the Lithium battery cuts-out (normally at about 10V). Even then, there will not be much life left in the battery after the panel has reported that the battery is low.
The ideal case is that the alarm panel can handle the different:
Charging voltage
Charging Current
Battery Low Reporting level of the Lithium battery
Even then, in an older alarm panel, it is still better than having to visit the customer every few months to replace the battery. Or even worse, the customer having to live with a non-working alarm.
A non working alarm is what we want to prevent as far as possible
