Try these just before you replace your inverter backup batteries

Every 2 or more years people plan to replace their inverter batteries due to decrease in the autonomy they provide.

It is typical for one to enjoy say 24 hrs (or whatever maximum autonomy a solution was designed for) backup when the inverter batteries were first deployed and after a couple of weeks or months the backup time begins to reduce until it no longer makes sense and the next thing is - plan to change the batteries.

I am not talking about manufacturer's defects in batteries that could render a brand new battery or a set of batteries in a battery bank useless in a matter of days or weeks.

Now, there are 2 things you need to do to ensure you get the maximum designed life out of a battery.

1. Ensure that you have proper voltage charging your battery or battery bank. The surest way to ensure this is for you to install a voltage regulator between the mains from the DISCOs and the AC power input on the inverter for charging purposes since you cannot trust and rely on the DISCOs to feed your office or home with steady 220V AC.

Forget the wide input range AC stuff you see on inverters, they only ensure that your inverters would work but the batteries are definitely not interested in such promises.

If you don't have well regulated electricity getting to the charger then your battery or batteries would not get properly charged and would gradually and surely pack up with time.

2. Get a battery equalizer if you are using more than a single battery if you do not have any. Battery equalizers help keep all the voltages of all the connected batteries equal during charging, when fully charged and when discharging them (when on inverter).

Batteries from the same manufacturing plant will still have small difference in their voltages and this small difference will continue to grow until it becomes a huge problem because a time will come when one or more batteries will always get overcharged while the rest are always undercharged since the upper and lower voltage cut off limits see a single DC voltage and not the individual voltages of the connected batteries.

Sort out these 2 issues and you will get to ensure your batteries longer than the typical 2 to 3 years people use them and begin to plan for replacements.

What prompted me to write this piece this afternoon?

I have a total of 5 batteries on 2 different inverters at home and all of them are over 2 years, some are in their 4th year in service and I had concluded that only the last battery could still be managed while the other 4 batteries have become weak.

I bought an installed a battery equalizer in one set of 2 batteries late last year just to get whatever extra power it can squeeze out of the set of batteries I consider to be the weakest.

Within the past few months I have had to run generators almost everyday, sometimes twice considering the fact that all 3 battery banks (2 banks actually and a single battery that is connected to a 1.5kva 12vdc inverter) would not last for 1 hr before going off.

Ikeja Electric appears to have suddenly provide close to 220V AC steady electricity in the past 2 weeks and apart from when they notify us about maintenance and repair works I cannot remember the last time I used a generator.

I have been switching between 2 inverters for the past 2 weeks since one set of batteries has been condemned as being bad until I tried to connect the set to electricity just in case.

It was called into service earlier today and the inverter has been on for well over 4 hrs. This set of batteries hardly gave out 20 minutes of electricity before 3 days ago for several months.

What happened? The batteries benefited from steady voltage from the grid. That's all!

Needless to state this, the other sets have been delivering over 4 to 5 hours each time they are put to work.

Remember, a few months ago none of them delivered more than 1 hr even when electricity supply may have lasted 8 hours so it wasn't really about the number of hours the batteries were charged but about the quality of electricity that was used to charge them.

The recommendations above are based on the assumption that the charging algorithm of the battery charging system whether from an integrated battery charger in an inverter or from a standalone (dedicated) battery charger.