Inverters and the Hype

This is something I posted on my blog sometime last year.

When you live in Nigeria, one thing that you are aware of is the electricity company. If you stay in town long enough, you will begin to ask questions about how they work and why their presence is always felt because the purpose for having them is actually why you are bothered that is, there is no LIGHT.
I am no writing about NEPA or PHCN. I don’t have the energy nor the LIGHT for that type of endeavor. I believe some brave heart Nigerian will take up that challenge. I am focused on a now popular alternative to NEPA/PHCN i.e the INVERTER.
Inverters are not new. Their operation and availability in the global market has been known to those in the power industry and science lab.
In the last few years, they have become ubiquitous with every person that can shell out the minimum cost acquiring them and talking about them.
In simple terms, inverters are direct current(DC) to alternating current(AC) converters. The DC is supplied by the batteries which stores the energy and the inverter converts that energy to AC. In compact systems, the inverter also acts as a battery charger or AC-DC converter so that when there is an external power source either from a power generator or AC mains supply or the output of a solar panel, the batteries can be charged.
While this is a contributor to why they are popular, it is the sales pitch that actually drives the huge interest in them. part of the sales pitch is as follows, they are silent, have auto-switch over, no fumes, no maintenance, e.t.c.
Basically these are the exact opposites of what generators are and when you look at the reality that almost every household has a generator, then the picture becomes clearer on why everybody is talking about inverters.
Now I wont talk about the various brands of inverters or various brans of batteries rather I will talk about the experience I had with my setup and use that opportunity to put something out here for posterity.
The typical system is made up of the inverter and the battery bank. of course you have breakers and interconnect cables and the likes (I advise you to use a qualified tech when attempting to install your system. He or she will know all the things you need to make it work). The typical battery voltage is 12V and this is installed as required either in series or parallel depending on your setup. This is not the battery type used in starting your car, those are usually high discharge current at small interval type of batteries rather, what you need is the Deep Cycle batteries. These batteries dont deliver very high currents like the car batteries rather, they can discharge what they can over a period of time without being ruined.

My setup is a 24V battery system which means 2 12V batteries in series. I had a nice time using it to the point that when I go to bed at night, and forget I am still in Naija because I sleep well and this is another selling point. Anyway after sometime I observed that the discharge time was dropping. It eventually came to a head when I was out of a fully charged system within 3 hours that was when I woke up from the honeymoon. After much test and tinkering, I found out that one of the batteries has lost some of its internal cells. Most batteries are built from a collection of 2v cells in series to form the big 12V batteries as we know them, a reminder of this is when you top up the battery electrolyte(water) and you have to open each cell to add the distilled water. Back to my story, the bad battery was not giving its portion of the load so the good battery was doing all the work and as it got weaker, I lost discharge time on my system.
Solution to the problem is that I had to change the 2 batteries to bring my system back to where is should be as well as incorporate a battery equalizer that makes sure that no battery is overcharged or over discharged.
I am not sure why my battery failed. But it was an expensive failure considering that fact that batteries are the major investments in the inverter setup. So for all the hype, that batteries last for at least 5 years, which is true in some cases, it is also very true that they can fail within a year and in some cases much less.
If you are shopping for a system, be interested in the quality of your batteries as well as the inverters and also be clear on the type of load you can put on the system irrespective of the size of your setup.
By all means enjoy your inverter it is a good thing.