பெரும்பாலான இன்வெர்ட்டர்கள், ட்யுபுலர் பேட்டரிகளை முற்றிலுமாக சார்ஜ் செய்வதில்லை

 அல்லது

 ட்யுபுலர் பேட்டரிகள் சந்தையில் கிடைக்கும் இன்வர்ட்டரை கொண்டு முற்றிலுமாக சார்ஜ் பண்ணும் வகையில் தயாரிக்கப்படவில்லை. 

An inverter does two main functions.

(i)                 It Converts 220V AC to  12V DC and stores the charge into battery.

(ii)               When there is no power, it converts 12V DC to 220V AC.

Batteries are available in different capacity such as 100AH, 120 AH, 150 AH / 12V DC etc.  Having 80% efficiency, a battery of 150AH  should able to deliver 40A discharging current for 3 Hours.(i.e. 120/40).

When  the following load is connected:

3 Ceiling Fans

4 Tube lights

then it would amounts to (3 x80 VA + 4x60 VA) = 480VA. (to convert Watts into VA, apply additional 20% on watts. eg. Fan 60-70W = 72-84VA ) .  So, the above load takes as near to 40A (480VA/12V) discharging current from battery. (It can be confirmed by connecting DC ammeter).  If 150 AH battery is fully charged, then for the above load, it should support minimum of 3Hours and maximum of 3Hours 30Mins

Another Eg: If you connect 2 Fan 2 Tube, ( 2 x 80 + 2 x 60) =  280VA = discharging current of 24Amps.  On this load, 150AH battery should support a back up of minimum 5 Hrs and maximum of 6Hrs 30 Mins.)

The branded batteries are being sold specially for inverters. So, the battery must be capable of being fully charged by inverters. If 150AH  battery is charged for 24 hours (excluding power cut time and non-usage in Inverter Mode) by a charging voltage of 14.4V and initial charging current of 10-12Amps (most of the inverters, available in the market come with above specifications) , then theoretically the battery should able to reach its full  capacity of 150AH. 

But, practically when 150AH battery is charged by an inverter, it charges to maximum of 80-90AH only.  Applying above load i.e. 480VA,   80AH charged battery gives only 2 hours backup. When above test is carried out ONLOAD (i.e. 3 Fans and 4 Tubes),  the battery terminal voltage initially, is somewhere around 12.30V, after 1 hour around 11.90V  and after exactly two hours, it gets cut off at 10.50V (most of the inverters are designed to cutoff at 10.50V).

So, we pay money for 150AH battery but actually we get only 80-90AH capacity out of 150AH.  Even, we charge the battery for 5 days, the above condition still prevails. I have tried with many batteries and different inverters, but the fact is that so far, no inverter could able to charge the battery to its full capacity.

When I take this issue to my battery supplier, they simply escape by saying that due to power cut, battery is not able to charge to its full capacity.  That is not a real fact. Today, not a single branded battery (tubular) is designed to charge to full capacity BY AN INVERTER (14.4V Charging Voltage and initial charging current of 10-12A).  But, when I made this as a serious complainant with battery supplier, in order to convince me,  they put the  battery on ’Bench Charge*’ i.e. constant current charge with ultimate peak charging voltage of 16.5V at their shop (which is not possible by inverters) and brought the battery to its full capacity of 150AH.   Thereafter, When I tested the battery with the above load, the battery gave a backup of 3H 30Min. No doubt that the battery is actually manufactured for 150AH capacity BUT  NOT DESIGNED TO CHARGE TO ITS FULL CAPACITY BY AN INVERTER.

When the manufacturer specifically state in their broucher  that   battery should be re-charged through an Inverter at constant potential mode of 14.4V till it reaches to its full charge and thereafter battery should be continued in float charge mode at constant potential of 13.8V, why the branded battery not being charged to its full capacity even if it is left for 5 days of continuous charge?

A consumer cannot take the battery every time to the dealer for Bench charge to bring it to its full capacity?   Due to non charging of battery to its full capacity by an inverter, a consumer is at loss, for his 40-45% of money.  When Battery manufacturer gives three years warranty, people are fascinated with warranty without knowing the charging ability of the battery.  

I have been discussing here, the charging of a new battery,   only to the level of  80-90AH  out of 150AH. Now, just imagine what would be the charging capacity of the same battery after two years?  

The battery manufacture takes advantage of the present power cut and sells the battery, which is not capable of being charged to its full capacity by an inverter. Sometime, battery supplier blame power cut and sometime they blame the inverter manufacturers.

MY CONTENTION IS THAT WHEN A BATTERY IS NOT CAPABLE OF BEING CHARGED TO MAXIMUM OF ITS CAPACITY, BY AN INVERTER WHICH IS DESIGNED AS PER SPECIFICATIONS GIVEN IN THE BATTERY BROUCHER, WHY IT IS MARKETED BY SAYING THAT IT IS SPECIALLY MADE FOR INVERTER?  AS PER CONSUMER PROTECTION ACT, THE WRONG PROPAGANDA TO A CUSTOMER ABOUT THE PRODUCT ITSELF AMOUNTS TO DEFICIENCY OF SERVICE.  WHEN THEY SELL BATTERY FOR INVERTERS, IT MUST BE CAPABLE OF BEING CHARGED BY AN INVERTER (NOT BY A BENCH CHARGE AT BATTERY SUPPLIER’S SHOP)

It is the duty of Battery manufacturer who make the battery for inverters, to prove their batteries are capable of being charged to its full capacity by an inverter available on the market or at least they should recommend the particular brand of an inverter which achieves the same effect.

If anyone  buy a brand new battery, please carry out above test (keep the inverter switch off) and confirm yourself to know the real capacity of your battery.  (If you have frequent power cut and the battery is being utilized intermittently, try the above test when you leave for 2/3 holidays). 

I have even tried with the inverters of battery manufacturer.  But, no improvement in the charging capacity. 

To conclude, I wish to state that olden days Automobile Batteries (thin plates) are used for inverters, which is capable of being charged by Inverters to its full capacity.  But, presently, the batteries are made with thick plates /tubular plates especially for inverters which are not at all capable of being charged by Inverters available in the market for its full capacity.

Actually, I am looking forward a Battery capable of being charged by an Inverter  to its full capacity.

Battery Charging Methods

There are two types of charging:

(1) Constant voltage charging - available with all inverters, wherein the charging voltage for battery is preset to 14.4 V. When the drained battery is connected to an inverter, due to potential difference between inverter charging voltage and battery voltage, the charging current is around 10-12A and terminal voltage of battery would be around 12V. After the period of 6-7 Hours of charging, the terminal voltage starts picking up to above 13V, and that instant,  due decrease of potential difference, the charging current decreases. Once the battery terminal voltage reaches 14.4V, the current will be somewhat around 1-2 Amp, called floating charge or trickle charge. On that time the inverter automatically decrease its charging voltage to 13.8V and maintain the charging current of 1-2Amps. Since the current is not constant over the period, the charging under this system for 150AH battery would take more than  24 hours. (if charged continuously)

(2) Constant current Charging (Bench Charge): Available only with Battery vendors – This method of charging is used for initial charge of battery by manufacturer and supplier - Initially Current is kept as constant at 12Amp/13V.  After few hours, when current decreases to 2-4A due to increase of terminal voltage of battery to 13V, the charger voltage is manually increased to 14V. Now again the current increases to 12Amp. Again the battery voltage picks up close to 14V, again current decreases to somewhat around 2-4A. Then, charger voltage is increased 16.5V. Again the current increase to 12Amp. Thus, the voltage is manually increased in such a way to maintain a constant current of 12A to charge the battery to its full capacity. In this method, if a battery is charged at constant current of 12A, the 150AH battery reaches its full charge within 13-15 hours.