The rechargeable battery pack comes in various configurations such as the rechargeable lithium ion battery pack, lithium polymer rechargeable battery pack, sealed lead acid rechargeable battery packs, etc.

That being said, we will look into the various rechargeable battery packs in details from the rechargeable lithium battery to all others. They all have their unique features and used for different purposes.

1. Rechargeable Lithium Ion Battery Pack

Rechargeable Lithium Ion (Li ion) battery pack continues growing because of their higher energy density, which is twice more than that of nickel as well as lead based chemistries, and their low self-discharge rates. Also, the rechargeable lithium ion battery pack possesses technology that makes them continue being safer and no expensive as the earlier rechargeable lithium battery types. The rechargeable lithium ion battery has various applications: Medical devices, Aerospace/military equipment, electric vehicles, consumer electronics, etc.

2. Lithium Polymer Rechargeable Battery Pack

The lithium polymer rechargeable battery technology is not too different from Li ion in several ways. The major difference is their packaging, where aluminum or steel cans are used for making li ion batteries, lithium polymer cells are in foil-like pouches. This makes packaging more flexible and provides safer operation as well as lower costs.

The technology behind lithium polymer cell is continuously improving with manufacturers introducing lighter, smaller and more powerful cells. The lithium polymer rechargeable battery pack comes in various and custom-tailored configurations which deliver higher discharge rates and longer run times. Their applications include Small consumer electronics (one or two cells), e-readers, tablets, smartphones, etc.

It should be noted that lithium has an inherent volatility, and lithium polymer has a high energy density which makes the battery and cell require a battery management circuit that controls and monitors its upper and lower voltage thresholds when charging and discharging.

3. Sealed Lead Acid (SLA) Rechargeable Battery Pack

The sealed lead acid battery is less expensive and easy to maintain which makes it of great benefit having various applications. Unlike lithium ion and lithium polymer, SLA batteries don't need a sophisticated battery management circuitry and do not need to be regulated for transportation.

They have the lowest energy density suitable for standby and stationary applications like emergency lighting and uninterrupted power supplies. This has made SLA cells easy to maintain as they are usually used for medical equipment and electric wheelchairs that need much power.

4. Nickel Cadmium (NiCd) Rechargeable Battery Packs

This is known to be a part of some of the oldest battery chemistries. Nickel Cadmium is still a popular and reliable technology despite the development of newer chemistries for rechargeable battery packs. They can last for thousands of cycles if properly maintained.

Their applications include their usage in aircraft and other stationary applications that are long-term.

5. Nickel Metal Hydride (NiMH) Rechargeable Battery Packs

The steady increase of the cell performance of nickel metal hydride has made its chemistry a very popular choice for applications that are lightweight, small and portable in nature. NiMH batteries, unlike lithium ion and lithium polymer, don't need sophisticated battery management circuitry for performance maintenance. Also, their rechargeable packs are not heavily regulated for transport.

More energy capacity than that of NiCd cells of the same size is provided of over 30-50%. NiMH cells also are less prone to the "memory effect" which NiCd usually go through. They are also more economical than lithium ion and lithium polymer rechargeable battery packs.