The Electric Vehicle Battery

The electric energy storage system found in an electric vehicle can be found in the form of a battery. However, the battery type within the electric vehicle is very much dependent on the model and type of battery chemistry found in the vehicle. Is it a (BEV), Battery Electric Vehicle or is it (PHEV), Plug-in-Hybrid Electric Vehicle?

Prior to the purchase, it is also important for the customer to consider: -

1. What will be the battery’s size?
2. What battery chemistry will be used?
3. What is the lifespan of the battery?

A typical electric vehicle battery, (40 – 60 kWh)  is designed for an average 8 to 12 year life cycle with a range of over 120 miles.  

Battery Chemistry; what the customer needs to know.  

There are 3 types of rechargeable batteries used in an electric vehicle with each having their own distinct advantages and disadvantages.

1. Lithium – ion, (Li-ion) battery
2. Nickel – metal hydride, (NiMH) battery
3. Lead – acid battery

1.Lithium-ion (Li-ion) battery

Advantages:

• Most common type of battery used in an electric vehicle
• High power to weight ratio than (NiMH) and lead acid batteries
• High energy to weight ratio than (NiMH) and lead acid batteries 
• Low “self – discharge” rate, (likelihood of the lithium – ion battery losing its charge when not being used) 
• Low maintenance
• Light weight

Disadvantages:

• Protection is necessary from being over charged and discharged too far
• A number of transportation restrictions must be adhered to

2. Nickel-metal (NiMH) batteries

Advantages:

• Have a longer life-cycle than lithium-ion or lead acid batteries
• With a high energy density a lot of energy can be packed into a smaller battery.
• Easy to recycle as they do not contain toxic metals

Disadvantages:

• High cost
• They generate significant amounts of heat during fast charges
• Heat generation makes these batteries less effective for recharging

3.Lead-acid batteries

Advantages:

• High power
• Inexpensive, safe and reliable.

Disadvantages:

• Poor cold temperature performance makes them difficult to use in electric vehicles.

When considering all these factors it is still important to remember that the way you maintain your battery does not affect its range, life span and performance.