How to Increase Battery Life – Lead Acid or Wet Batteries

How to Increase Battery Life: You would agree that your home batteries can be much more demanding than inverters – they need frequent water top-ups or they may not give adequate backup even after being fully charged and in some cases, you may have to replace the batteries soon after buying them. Your inverter can last up to 10-15 years but batteries won’t last more than 4 years. Why?

Did You Know: Batteries could be two times more expensive than inverters. Most Batteries that come with a warranty of 36 months do not last more than 40 months.

Of course, every battery has a life span (like living beings) which is made up of charge and discharge cycles. No battery will last forever but a lot also depends on the way it is charged.

What happens when you don’t sleep properly for one night? Your productivity during the day will be low and the next night you will go to bed much earlier. If you don’t sleep properly for a month? You may get sick and may have to be admitted to a hospital. The same happens with batteries. As sleep is very important for us, correct charging is essential for batteries.

The many problems that you face with your home batteries are a result of improper charging. If your home inverter that charges batteries (or solar charge controller in case of solar installation) is good, you can get freedom from these troubles and increase battery life by 6-12 months.

3 Things That Can Increase or Decrease Battery Life

1. Outside Temperature

Change in Temperature Can Harm Battery Life and Its Ability to Hold Charge.

Reason: Wet Lead Acid batteries contain an electrolyte that expands at hot temperatures. It means that the electrons are now freely moving and the battery can achieve a full charge with less boost charge voltage. But the problem is that many inverters can’t detect outside temperature.

The inverter manufacturers set the boost charge voltage assuming a temperature of 25 degrees Celsius. However, in summers the temperature can go up to 40 degrees. If the temperature increases and your inverter’s charger keeps charging the batteries as if it was 25 degrees then it will lead to overcharging of batteries.

Studies have proved that continuous overcharging of batteries can decrease battery life by 50%. It also causes leakage of toxic fumes from batteries because batteries are made of sulphuric acid.

The opposite happens when the temperature is low. In cold temperature, the battery’s chemical would achieve a near-freezing state. It would need more boost charging voltage than it would if the temperature was 25 degrees. However, the inverter can’t detect outside temperature and doesn’t increase boost charging voltage. This results in undercharging of batteries.

According to research, if batteries remain undercharged, they will lose the capacity to hold 100% charge. Basically, you will not get a good backup even if the battery is fully charged. The problem, right?


Choose an inverter that has the ability to detect outside temperature and regulate charging voltage based on that. This technology is called Automatic Temperature Compensation. Many chargers that are used to charge batteries in cars have this feature. If the temperature is too high then they decrease the boost charge voltage and increase it when the temperature is low.

Also Read: High temperature Affects Tubular Battery Life

2. Sulphation

Wet batteries or LA batteries are made up of sulphuric acid and water. If the battery remains undercharged during many charge cycles, it may cause the build-up of sulphate on the battery’s plates. What it simply means is that the acid in the battery has reached such a deep discharge state that it has begun to cover the lead plates of the battery. If this is not taken care of, it can lead to the death of battery!


Choose an inverter that has the feature of desulphation. Most of the inverters in the market charge batteries only in two or three steps they start by giving a bulk charge to batteries and finish off by bringing the battery in a state of 100% charge. They don’t do anything to counter sulphation.

3. Deep Discharge of Battery

Battery Reserve - Battery Life

Has your battery got so discharged that it gets impossible to charge it again? Even after giving it a sufficient power supply for long hours the battery holds no charge and is not able to give any backup. Yes, this condition is called deep discharge.

But at what voltage does the battery go into deep discharge mode?

Every battery has a reserve capacity. For example, if a fully charged 12v battery has a voltage of 13v, your inverter should not allow you to drain it beyond 10.5. If it reaches below 10.5 then your inverter should show ‘battery low’ and start the charging. But the problem is that ordinary inverters in the market don’t do this – they may drain your battery to a dangerous level of 9.5 or even 9v. If this happens repeatedly then your battery will not be able to hold 100% charge.

A Cool Example: Did you know that if you only charge your mobile phones’ battery when it completely dies down then the battery will not be able to remain 100% charged for a longer period of time? In fact, this is also the reason why your phone shuts down when the battery is very low. This happens to protect the battery from deep discharge.


Setting your battery cut-off voltage at 11V can be quite beneficial for your battery. With this setting, it’s logical that your battery will get charged faster and it will consume less power every time you recharge it. By choosing 11V you are preventing your battery from getting fully discharged every time and your battery will remain fit and healthy!

Use an inverter that automatically disconnects the battery when it reaches 10.5v. Modern home UPS and home solar inverters have these features. They have a small switch at the back where you can choose the battery reserve to 11v or 10.5v. We would recommend 11v because it is good for the health of the battery to have more reserve. But then you may choose to get the maximum out of the battery – no problem! In either of the cases, it will not let the voltage drop below 10.5v.

We can assure you that if you take care of the above 3 things you can prolong battery life. The battery which is supposed to last 24 months will very well last beyond 30 or 35 months. Now that is a huge saving – not only in terms of money but for convenience as well.

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