Types of Rechargeable batteries for Solar Panels

Solar Energy System generate power during the day as the sun shines on the solar panels and depending on the system it will power your devices and have enough to store for later. Solar power can be used to recharge many types of batteries from consumer level AA batteries all the way up to 48V batteries.  

Without batteries you won’t be able to harness the full potential of your system. We look at the different types of batteries you can use to store power your solar panels.

Batteries are made up of positive and negative terminal material, separated by an electrolytic medium (something that allows the flow of electrons from one terminal to the other).

The batteries will vary in chemistries, applications and price points.


Lithium batteries are the newer type of batteries compared to the lead acid (we cover them next) that are the traditional.


Lithium-ion are the most common types of batteries that you’ll find in laptops and phones. The electrodes are lithium cobalt oxide (LiCoO2) and graphite with a solid lithium electrolyte.

Lithium ion batteries are light with a high energy density but can also be recharged quickly and deliver a constant current.  

Lithium Polymer

Lithium polymer are still under lithium-ion batteries and are referred so because it uses high conductivity polymer gel/polymers electrolyte instead of a liquid electrolyte.

Lithium Iron Phosphate

Lithium Iron Phosphate are a type of lithium batteries that use phosphate as the cathode. LIFEPO4 batteries have a longer life span with up to 2000 lifecycles and are safer. However they have a higher self-discharge and are a bit heavier that Lithium-ion.

Lead Acid

Lead Acid batteries are the traditional types of rechargeable batteries used for off grid power storage. You’ll find three types of lead acid batteries in the market namely Wet or Flooded, Gel and AGM batteries.

Flooded Lead Acid Batteries

Flooded Lead Acid batteries are an old school type of battery that required maintenance by filling up with distilled water regularly. This is why they are referred to as wet or flooded. They are cheap but are very bulky and require ventilation as they emit gas.

Gel Batteries

Gel batteries are referred to as zero maintenance batteries. This is because the liquid from the wet batteries was replaced with jello like material. The battery is also sealed so removing the labour of having to refill with water.

However they will cost more and are sensitive to high currents.

AGM Batteries

AGM batteries, or Absorbed Glass Mat, like are also a type of lead acid battery with another twist. They are referred to as “dry” or “starved” electrolyte. The batteries use a fine fiber between the plates to hold the electrolyte.

This makes them another maintenance free type of battery and is they are also great for portable applications. They are also more efficient and don’t freeze easily.

They are more expensive than the wet types but are definitely worth it for the upgrade.

Marine or Deep Cycle batteries are a special purpose battery designed to provide a constant current for long periods.  Automotive batteries are designed to produce a high current for a brief period to start the motor.hese are the recommended type to use in a solar system but the size will depend on your needs.

NiCd (Nickel-Cadmium)

NiCad batteries are made from Nickel-Cadmium and are a dry rechargeable type battery.  NiCad are used in many electronic devices like power tools and emergency radio. They are used in solar lights but do not have the capacity required for a home solar energy system.

NiCd batteries have the shortest charge time and can deliver a high load current and are quite cheap. However they require high maintenance as they suffer from memory effect and require a full discharge in order to maintain their capacity’s.

NiMH (Nickel-Metal Hydride)

NiMH have a higher energy density than NiCd and don’t suffer from memory effect. However the NiMH batteries suffer from considerable high-self discharge

Because NiMH are more environmentally friendly they favored more than NiCd batteries.

An effective use of these batteries in Solar lights. Solar lights use rechargeable batteries that are powered through a small solar panel fitted into the solar light. It is charged through out the day to provide power all night long. They can be charged for more than 1000 times and used again.

However, in the initial stages, using these batteries can be a little difficult as their power drains out without any alarm or sign. Thus, you always need spare batteries which can help you continue with your work while the other set of batteries get charged.

The rechargeable batteries have the same components as the primary batteries. They comprise of a positive electrode, a negative electrode, a separator and electrolytes (chemical solution). But, unlike primary batteries they can be easily recharged and used again anytime you want.

These LSD batteries can outlast the normal alkaline batteries. The LSD batteries are available in AA, AAA, C, D and also 9 volt sizes. Among them, the C, D and 9 volt batteries that are not very easily available

Types of Battery By Size

Name  Shape LengthWidth (Diameter)Volts
AA Cylinder50 mm14.2 mm1.5 V
AAA Cylinder44.5 mm10.5 mm1.5 V
AAAA Cylinder42 mm8 mm1.5 V
C Cylinder46 mm26 mm1.5 V
D Cylinder58 mm33 mm1.5 V
9V Rectangular Height 48.5 mm26.5 mm17.5mm9 V
123 Cylinder34.5 mm17 mm3 V
CR2 Cylinder27.5 mm16 mm3 V  
N Cylinder30.2 mm12 mm1.5 V
J Square with missing corner Height 48.5 mm35.6 mm9.18 mm6 V