Lithium-ion batteries (LIB) batteries were initially made for use in laptops, cell phones, and other consumer electronics but they have grown to become a major battery technology for power storage systems. In addition, they have become the most common battery type in modern electric cars.

Batteries play the same role in inverter and solar systems, namely, they provide the DC that is to be converted to AC by the inverter for use in appliances. Lithium-ion also store energy produced from solar panels for later use. All batteries have essentially the same components: electrolytes, positive and negative terminals, and separators integrated into ‘cells’.

Everything To Know About Batteries Inverter 

These components are often differentiated based on the nature of the material from which they are made. The most important and definitive component of all batteries, the electrolytes, may be in liquid form as in lead-acid batteries or in the semi-solid gel form. In the case of LIB, lithium salts dissolved in an organic solvent are used. Also, there may be variances in the type of electrodes or terminals. For LIB, the positive electrode is a metal oxide, and the electrolyte is a lithium salt in an organic solvent. (Water is not used as a solvent as lithium reacts vigorously with water.)

The most popular negative electrode used in the manufacture of LIB is graphite.

The positive electrode is generally one of the three-layered materials of lithium salts. Recently, graphene-containing electrodes (based on 2D and 3D structures of graphene) have also been used as components of electrodes for lithium batteries.

The electrolyte is typically a mixture of organic carbonates containing mixtures of lithium salts. A modified variant of Li-ion batteries, the lithium polymer battery, or more correctly lithium-ion polymer battery (abbreviated as LiPo, LIP, Li-poly, lithium-poly, and others), uses a polymer electrolyte instead of a liquid electrolyte.

Advantages of lithium-ion
  1. Their main attraction is that they do not require constant maintenance. They are a type of sealed maintenance-free battery types.
  2. Also, they weigh far less than other types of rechargeable batteries of the same size and output capacities. The reason is that the electrodes of a lithium-ion battery are made of lightweight materials. It takes up less space and is thus more suitable when there are space considerations.
  3. They do not have to completely discharge before recharging, as with some other battery technologies. They have a very much longer life than other battery types.
  4. Comparatively, Li-ion batteries charge extremely faster than other rechargeable batteries. The reason why lead-acid batteries require a three-stage charging profile where each stage progressively lowers the charge current and can be bulk-charged up to 80%, then absorption-charged from 80% to about 95%, and then float-charged to 100%. Li-ion batteries however do not have such a similar three-stage charging and can be bulk-charged all the way up to 100%.
MORE ADVANTAGES
  1. Li-ion batteries can withstand very rugged power conditions than other types of batteries. They can supply electricity to very high-power appliances.
  2. Under the same conditions, LIB is far more efficient than lead-acid batteries. Lead-acid batteries only have a charge efficiency of 85%. This means that for every 1A sent to the batteries, only .85A are store for use. Lithium batteries however have a charge efficiency of 99% so nearly every amp sent to them is store and usable. Therefore, a lead-acid battery bank will require a 15% larger – and more expensive – solar array to charge it as fast as a comparably sized lithium battery bank.
  3. The lifespan of lithium batteries is significantly higher than that of normal lead-acid batteries! Some manufacturers warranty their Li-ion batteries to last 10,000 cycles. Most lead-acid batteries are only rated for 400 cycles or less. This means li-ion batteries will last ten times longer than their lead-acid The lifespan of lithium batteries is significantly higher than that of normal lead-acid batteries! Some manufacturers warranty their Li-ion batteries to last 10,000 cycles. Most lead-acid batteries are only rated for 400 cycles or less. This means li-ion batteries will last ten times longer than their lead-acid
Disadvantages of lithium-ion
  1. The single most important disadvantage of LIB is its cost. They cost up to three times the cost of conventional batteries per Ah.
  2. They are extremely sensitive to high temperatures. Heat causes lithium-ion battery packs to degrade much faster than they normally would.
  3. They have a very low shelf life thus when in storage, they have to be recharged from time to time. Also, they have to be stored under temperatures lower than 40 degrees. (The shelf life of a battery is the time an inactive battery can be stored before it becomes unusable. It is usually considered as having only 80% of its initial capacity. The conditions under which a battery is stored either by the dealer or the user will determine its shelf life and in turn, eventual lifespan.
OTHER DISADVANTAGES
  1. Again, if lithium-ion completely discharges, it will be permanently damaged. Typically, this is accounted for as many inverters will automatically shut down when their batteries are being discharged below their depth of discharge because the batteries may be permanently damaged if fully discharged.
  2. They require an onboard protection circuit to maintain the battery voltage. This makes them even more expensive than they already are because of their manufacturing costs. The goal of the protection circuit is to limit the peak voltage of each cell during charge and prevent the cell voltage from dropping too low on discharge. In addition, it helps to monitor the cell temperature to prevent temperature extremes. With these precautions in place, the possibility of metallic lithium plating occurring due to overcharge is virtually eliminated.
  3. There is a small chance that, if a lithium-ion battery pack fails, it will burst into flame.
  4. There are often transportation restrictions on the shipment of larger quantities. (This restriction does not apply to personal carry-on batteries.)

 

if you are using an inverter set then I am sure you are already seeing its benefits. One challenge you are probably already facing is your battery backup time not lasting as long as you would really like it to.

Your battery bank is measured in AH (with a voltage rating too) and determines how long your inverter can power its current load. It is important you do not mix this up with your inverter’s kVA rating. To help you understand the difference easily,

Inverter kVA rating determines how many appliances you can power at a time
Battery AH rating determines how long your inverter can sustain your current load (appliances you have on)

 

 

HOW TO EXTEND YOUR BATTERY BACKUP TIME

Unless your batteries are damaged, there are some techniques you could employ to significantly increase your backup time (how long the battery powers your appliances before it goes flat).

Integrate a battery equalizer

Uneven charging and discharging are reasons why you might not be getting the most out of your batteries. When you have batteries connected in series and any charges to 100%, all others stop charging even if they are just about 70% charged. When discharging, if any goes flat then all others too stop discharging even if they are still at about 70%.

This uneven charging and discharging is because of the batteries not being 100% identical (even if they are of the same brand and specs) and it builds up over time. This not only cheats you out of battery time but also could cause the batteries to wear easily due to over-charging and over-discharging

What a battery equalizer (Battery Management System) does is to ensure that the batteries are charging and discharging at the same rate so you have optimal charging and discharging.

 

Know how to read your current battery level

In business, they say “If you can’t measure it, you can’t improve it” The same applies to your battery bank. If you do not know how to tell what your current battery level is then how do you know when it is time to put off heavy appliances to save power? The battery level is hinted on the Inverter’s monitor but you will have to wait to see it because lots of other info are displayed at intervals.

Some inverters display battery bars while others only show current battery voltage. For such inverters, you take note of the battery voltage when fully charged (this will be indicated with a Battery Fully Charged message) and when empty (the inverter emits a steady beep to indicate). This way, you know your battery level at any given time and can adjust your usage accordingly.

Switch to energy saving appliances

One way to boost your battery time is to avoid running heavy appliances on the inverter (at least not for long). Your Home Theater system alone could be hogging 360 – 1,200 Watts, which is huge!

Reducing the number of appliances you have on at a time is not all, you should go the extra mile to switch to energy saving appliances.

Instead of those 60 – 100 W bulb (that cause your house to feel hot), switch to 3 – 12 W energy saving bulbs. I agree they are more expensive but the extra battery time you will get would mean less money spent on Fuel + Generator maintenance over months. When shopping for ceiling fans, ask for very good light-coiled fans. Energy saving refrigerators and deep freezers, energy saving everything!

Concentrate activities that require power

Having a routine helps you utilize your battery backup time effectively. From experience, I have learnt that I tend to be careless with my power usage when I do not have a schedule for when the inverter should come on and for how long. For example, you watching your favorite TV show only to realize you had not been charging your phone just when you are about to power off the inverter. Now, chances are that the fan or other appliances were on while watching TV. Leaving the inverter on just because you want to charge your phone means the fan and some other appliances will stay on longer which translates to more battery consumption.

Upgrade your battery bank

Upgrading your battery bank is another way to extend your battery time. This is a costly approach but sometimes, your battery bank just is not enough. You do not necessarily have to change your entire setup or discard your current batteries, just add more batteries. The number and specs of the batteries you will need to buy depends on the specs of your current setup and what you really wish to achieve. I will give an example:

Let us say I have a 2.5 kVA; 24V inverter. This means the battery bank must equal 24V no matter how many batteries I connect. Let us say I opt for 12V 100AH batteries. I would need at least 2 connected in series so that it equals 24V (12+12).

Now, if I wish to upgrade by battery bank; I will have two main options

Buy another 2-100AH 12V battery so I have 4 100AH batteries in all

Discard my 2 100 AH 12V batteries and buy 2 200 AH 12V batteries

As you can see, upgrading my battery bank depends on my preference, I might not want to sell or give away my 100 AH batteries so I buy more and get a 4-battery rack. I might – on the other hand – not like the clutter of many batteries and opt for fewer, more powerful batteries.

TIPS TO EXTEND THE LIFE SPAN OF YOUR BATTERIES

Apart from extending your battery backup time, you should also take good care of your batteries so they last longer and here are some tips:

Ensure to use the rubber battery terminal protectors to avoid dust and rusting of the terminals

Ensure your inverter setup is in a well-ventilated area to prevent heat from damaging the batteries.

Avoid overcharging and deep discharging (using the battery until empty). Go for an inverter that automatically protects your batteries against these.

Avoid leaving the battery idle for a long period without any form of charge or discharge activity.