FGWilson Telecom Blog

How to calculate battery life and discharge rate.

This is a question that one of our readers asked regarding BATTERIES, and more specifically, if there was a way of estimating in a more straight forward way its life and discharge rate.

Answer:

In reference to your question, I’ve done the following research..

Even though people consult the way of estimating the discharge rate batteries have, it is difficult to give a mathematical equation for it, since there are external parameters like: :

LVD

Operating Temperature

Battery Parameters

We can make an approximate estimate in the following way:

I send you the data for the batteries on my system, for Tudor batteries, you should look at the data sheet.

Taking as an example a monoblc battery similar to C&D (TEL 12-105F model), this is: C[Ah]= 105Ah @8hrs! @25Cdeg! @VF=42VDC! @new! @fully charged!, from the tables (or curves that the manufacturer gives, you could get):

 

LIFE IN HOURS FOR EACH SAMPLE OF LOAD:

t= 10hrs for a load of = 10.2Amps

t= 8hrs for a load of = 12.5Amps

t= 5hrs for a load of = 18.5Amps

t= 3hrs for a load of =  28.2Amps

*** For approx. 30Amps mentioned, this model C&D should last a little less than 3 hrs ***

t = 2hr for a load of = 38.8Amps

Have in mind the factors in bold (see above) since they affect in a DIRECT way the back-up time of the bank.

Something else to highlight is the amount of energy you extract from the same battery, this one behaves like one of less Ah, which is to say that its “performance” is not “constant”.

The initial kick-off of mobile phones.

33 years ago, Motorola’s CEO was making the world’s first call on a cellular phone. Today, technology has gone a long way.

Know a little of what, in only three decades, became a great success.

33 years ago, on April 3rd 1973, Motorola’s CEO Martin Cooper, was making the first call on a cellular phone in the city of New York.
The device was the prototype called DynaTac, AKA “brick”, and was only available to the public 10 years later when Motorola was able to get the license in order to market it. That same year, the first cell phone network was set up.

 

The commonly known “brick” weighed 780 grams and measured 33 x 9 x 4,5 centimeters  (that is why it had that nickname), which today would be ridiculous  since the new phones weight approximately 90grams.   
The first cellular phone had an approximate cost of between 3 and 4 thousand dollars, and the promoters and investors of this new technology were expecting to reach the year 2000 with a market of 900,000 users. But... as usually happens with these estimates, they miscalculated tremendously, since today, in 2006, there are more than 2 billion cell phone users. How this cellular phone technology worked, was simple to understand, even for the most unskilled and reluctant ones to new technologies. This phone would send a signal to the receiver antennas that were installed in the area where the user of the terminal was. Each installed receiver antenna would cover around 15 square blocks and the pulses were sent to a central processor that was in charge of choosing the best channel in order to connect the call.
Now, 33 years from that first cellular phone call, it is possible not only to expect the receiver antenna to make the call, but also to send text messages, audio multimedia messages, photos and videos. Screens went from their originally green to full color flat screens, and cell phones became an essential tool for most users. Games, to browse on the Internet, camera and camcorder, calculator , planner, caller ID, ring tones, recorder, mp3 players and voice command are only a few of the features of most of these devices. You can listen to the radio or watch TV from these simple devices.

In the beginning, we just knew Motorola. Now the market has more than 10 different companies that manufacture the most modern and innovative devices, with new technologies that impress us every day. Samsung, Motorola, Nokia, Sony Ericsson, Smartphones, Firefly, Siemens, Alcatel, are only a few of the most famous ones.

The development of cellular phones modified radically the means of communication and the habits among people and their way of communicating. What can we expect in ten years from now?