Why do I experience quick solar battery discharge? (How to fix them)

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Yes, this question of why do I experience quick solar battery discharge on my system always arises. Especially months or years after installations. No doubt that clients may experience quick drainage of solar batteries after years of installation, especially during the night. So many factors are responsible for this, ranging from the installation and the management of the solar grids by the owner. A good solar battery installation should at least last up to 6-7 years before it starts to discharge fast. Most times the installer is the one who causes arms to our solar installation work without knowing.

Below are the things we do that are affecting our solar system batteries and making them discharge fast when in use.

What Causes of quick drainage of solar batteries when in use?

There are so many factors that can contribute to the reasons solar battery discharge fast. The following are the factors and things to be done to avoid them.

Not using a solar charge controller on our solar installation.

Most of the time, due to economizing on money and material some installers fail to use a solar charge controller in their works. This can be so dangerous and harmful to the solar batteries and also to us making use of the solar. This makes the battery to be either experience a low or high charging rate. Which will weaken the battery cells and make the solar battery discharge quick during operation. The solar charge controller is a vital device on our solar grid and we should always consider it when installing solar. Something solar battery can explode due to overcharge because there is no charge controller to regulate the charging

How to choose and size a charge controller for your solar energy installation.

insufficient charging of the solar battery.

this is when the solar battery is not charging the way it supposes to charge. Most of the time the cause can be inadequate solar panels to give the battery a healthy charge. At times the solar panels we have are not enough to charge the number of batteries we are using on 24hrs. And during the night we will quickly drain the batteries because the batteries are not fully charged during the day. When the solar batteries are not having adequate charge, it starts to weaken the cells of the batteries making them not last long during operation. We should always make our calculations correctly in choosing the number of panels to use when installing a solar system.

How to safely maintain solar panel modules.

Staying long without charging a drained solar battery

Most time maybe during vacations, most people disconnect their solar grid before going on vacations. And when disconnecting them they don’t think about whether the batteries are charged or not. When we disconnect unchanged batteries and leave them for a long time without recharging the batteries. It affects the cells of the battery and can even damage the battery. So while going on vacation or disconnecting a solar battery, always make sure the battery is fully charged for the safety of the battery cells.

Overloading the solar batteries.

when we overload a solar battery, we make the energy drain more quickly and something even short down leaving the area on blackout. Overloading of the batteries for long periods affects the batteries and can make them discharge fast. Is always advisable to make load shedding and make sure not to overload the batteries to make them last longer. With a good load shedding, we avoid over-stressing our batteries and make our solar more satisfying.

poor solar battery maintenance.

With no doubt, we all know the poor maintenance of something will lead to a short serving duration of the thing. The way we handle our solar batteries at home contributes to how long they will serve us without developing issues. Something is a lack of knowledge on how to handle solar batteries.

We should always take good care of the batteries by doing the following things.


  • Always make sure the batteries are in a good ventilation environment.
  • Avoid keeping the batteries on a bar floor. Battery rank should be used to arrange the batteries.
  • Avoid keeping the batteries under the sun or in a hot environment.

The above mention factors are not healthy for our batteries. if the immediate preventive measure is not taken, it can damage the battery and make it discharge fast.

How to know if the solar battery is completely bad.

Quick drainage of solar battery most of the time affects the battery life span if not noticed and corrected on time. You can correct the cause of the fast drainage of batteries but the battery is still draining fast. In this case, it means the batteries have been affected by the system. In this case, get battery testers meter and check the condition of the battery.

To determine whether the battery is completely bad or still ok to revive back. The following test and inspection should be done on the battery.

  • Carry out visual inspection on the battery.

bring out the battery and have a close inspection around it. From this simple inspection, you will be able to tell how good the battery is.

If there is a bulge on the battery, then it shows the battery is bad.

The major cause of this is a result of overcharging the battery. Overcharging most time affects our battery bank and we always advise a good rated charge controller to prevent this type of damage.

explosions, on the battery.

Sometimes the battery when got short circuit can explode and cause damage to our solar grids or other devices. We should be careful the way we handle the solar batteries as the explosion is dangerous to people around it. Is always good to safely guide the batteries with a breaker or fuse to prevent the damage of batteries when short circuits.

licks or whitish particles around the terminals of the battery.

This is seen as the battery starts to stay long. but most time is caused by not connecting the terminals of the battery to be firm. Cable logs should always be used to terminate the cable end. washers and nuts too should also be used to tighten the battery well to avoid this type of fault on our batteries.

How to check solar battery using a battery tester.

In testing the solar battery to know if it is still ok or faulty. You need to have a multimeter. This device is affordable depending on the quality you want to purchase. You can get them from any electrical store or make an order from any online store.

How to test solar battery using a multimeter.

get the meter and test for the voltage of the battery. If the batteries and interconnected together, lose them separately and test them separately. Set the meter in DC voltage mode and select the range you are testing. Don’t select a range below the battery you are testing so that you won’t damage your testing device.

If you got a voltage before the battery voltage, it means the battery is not too healthy. But when the tested voltage is far below the battery voltage, is a sign the battery is dead already.


when planning for solar system installations, we should always consider the mode of charging the solar batteries to make sure they charge well. At the same time, we should go for a good quality charge controller to moderate the charges entering the batteries. And also inspect the installations from time to time to notice faults on time before it causes damage to the system.

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2 thoughts on “Why do I experience quick solar battery discharge? (How to fix them)”

  1. Pingback: how many solar panels are needed to charge a 200AH battery? - Sparkrey

  2. Pingback: What size of solar panel to charge a 200ah battery? - Sparkrey

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