Home > Information on batteries and battery bank sizing

Batteries store the energy your inverter converts to usable electricity.

This means that without a good battery bank (total number of batteries you may be using in your backup plan) you will not have a smooth ride at all.

JAP does not manufacture batteries neither do we sell them, however, we try as much as possible to help all our clients get good batteries as there are a lot of lesser quality or fake batteries in the market.

This also means that our one year full warranty does not cover the batteries even though we do all we can to make sure your batteries are in very good conditions at all times.

Types of batteries

For sake of simplicity we shall categorise the batteries as wet, gel or dry type.

Wet cell type are the common ones we see everyday and use in our cars, they are cheap when compared to the other 2 types but are not ideal for long discharge periods. Even at that, it remains the most cost effective option for your alternative energy needs.

Gel type basically uses immobilized electrolyte, are more expensive, better suited for alternative energy, maintenance free.

Dry cell type remains the most expensive, maintenance free and infact if you can afford it then go for it.

We still prefer the wet type and advice clients to use them unless money is not an issue.

Battery bank calculation

How do you know the number of batteries that will provide the backup you need?

To begin with, it is assumed that you have calculated the total load you want to provide backup for.

For this example let us say you need backup for 1 TV, 1 laptop, 2 fans and 4 bulbs.

Estimates

1 TV - 140W
1 Laptop - 100W
2 fans - 200W
4 (15W bulbs) - 60W

Total - 500W

So your load is 500W

Reminder: If you have a 500W load and you need to size your inverter make sure that you will accomodate for surges (starting power which may be 2, 3 or more times the rated power) that means for a typical 500W load you may use any inverter from 1000VA up.

Let us assume we want our backup to last for 24 hours non stop assuming that all the loads will be running concurrently here is what you do.

500W x 24 = 12000W or roughly 14000VA

Divide this by the acceptable depth of Discharge of most batteries (80%)

14000/0.8 = 17500

This represents your total power need, so you must provide a battery bank that can handle this.

Again, let us assume that you want to use the 12v 200Ah battery with total power of 12x200=2400

So, you get the number of batteries by dividing your total energy needs by the rated power of any battery you may choose to use, in this example we will be needing

17500/2400 = 7.29 = 8 batteries

So, if your backup plan changes to just 12hrs instead of 24hrs, you can safely use the same inverter but with 4 batteries instead of eight batteries. You can double the battery bank to 16 if you choose to design for 2 days or 48hrs.

Just remember that you can design for any lenght of backup time as long as you have the money to pay for batteries.

Battery prices (we do not manufacture them, use as a guide)

12v 200Ah (regular wet cell type)- N29,000.00 per unit

12v 200Ah (gel type) - N45,000.00 per unit

12v 200Ah (dry cell type) - N54,000.00 per unit