Last Updated on February 10, 2023 by Matt
In this guide, we will look at the differences between lithium-ion and lead-acid batteries, and learn why one of them has become pretty much obsolete, while the other one has taken over the world of electronics and gadgets.
Lithium-ion batteries have proven to be more powerful, more reliable, and more durable than lead-acid batteries. They have a considerably higher energy density, lower self-discharge, and a more compact design than lead-acid batteries. Also, they have a longer lifespan, charge faster, and are more environmentally friendly when compared to lead-acid batteries.
Lithium-ion vs lead-acid battery
Lithium-ion and lead-acid batteries are the two most common types of batteries used to power electric vehicles.
Lithium-ion batteries are considered superior to the rest of electric vehicle batteries and are a standard for this type of transportation as well. They may be a bit costlier than the alternatives, but they also have a lightweight design and high energy density, efficiency, and terminal voltage. In fact, these are just a few of the many properties their superiority is attributed to.
Lead-acid batteries are cheaper, but typically that’s where the advantages end. They are older technology, usually perceived to be inferior to modern batteries in terms of capacity, efficiency, charge rate, and weight.
Which one should you choose?
In most cases, the choice will be made for you. Lead-acid batteries are pretty much on their way out, and can only be found in just a few gadgets today. In electric scooters, lead-acid batteries are also very rare, and only a few older models or models for children come with them.
Lithium-ion battery: The basics
A lithium-ion battery is a rechargeable battery that uses a carbon-based anode, lithium oxide-based cathode, and lithium salt as an electrolyte.
Electric vehicle enthusiasts appreciate lithium-ion batteries for their compact and lightweight design and low self-discharge.
However, it can’t be all good news. If a lithium-ion battery is charged at a higher voltage, it can degrade faster than a lead-acid one. Similarly, being highly sensitive to high temperatures, a lithium-ion battery can catch fire and cause damage if overheated.
Additionally, while lithium-ion batteries may be more powerful than lead-acid batteries, they require more protection in order to work properly and last longer. So, if you own a lithium-ion battery-powered scooter, bike, or motorcycle, make sure you keep its temperature as well as voltage and discharge rates within safe limits.
How does a lithium-ion battery work?
This type of battery works by transporting electrons from one electrode to the other during discharging and charging.
During the discharging process, i.e., when the lithium-ion battery is powering, let’s say, your electric scooter, electrons travel from the negative towards the positive electrode. During the charging phase, this process is reversed.
Lead-acid battery: The basics
A lead-acid battery is also a rechargeable battery, but unlike the lithium-ion battery, it uses lead as a negative electrode, lead oxide as a positive electrode, and sulphuric acid as an electrolyte.
The main reasons lead-acid batteries are commonly used in many different transportation devices are their low cost and high power-to-weight ratio. Also, they’re considered highly suitable for starter motors of vehicles that require strong current.
Compared to lithium-ion batteries, lead-acid batteries are weightier and have lower efficiency and energy density. They also take longer to charge and have a shorter lifespan. These weaknesses are the reason why many electric vehicle owners prefer lithium-ion batteries over lead-acid batteries.
How does a lead-acid battery work?
The discharging and charging phases of lead-acid batteries involve electrochemical processes similar to those in Li-ion batteries. A lead-acid battery differs from a lithium-ion battery in terms of the way it works in the following ways:
- Atoms flowing from the positive to the negative electrode
- Electrons traveling from the negative to the positive electrode
- Hydrogen and oxygen gases are produced during charging
- In between the discharging and charging processes, the voltage of the battery reduces
Lithium-ion vs lead-acid battery differences
| Parameter | Lithium-ion battery | Lead-acid battery |
|---|---|---|
| Energy density | High | Low |
| Capacity | High | Low |
| Efficiency rate | 95% | 80-90% |
| Working temperature | -30 to +80 °C | -20 to +50 °C |
| Depth of discharge | Low | High |
| Size and weight | Compact and lightweight | Bulky and heavy |
| Charge rate | 2-3 hours | 8-9 hours |
| Installation | Easy to install | A bit difficult to install |
| Maintenance | Require less maintenance | Require frequent maintenance |
| Cost | Expensive | Cheap |
| Lifespan | Long | Short |
| Safety and environmental impact | Medium | Medium |
If we take a closer look at the table presented above, we can see that there are several major differences between lithium-ion and lead-acid batteries. These differences include:
Energy density
As it can be seen from the chart above, lithium-ion batteries have high energy density. This is probably the main advantage they have over lead-acid batteries and the reason why they’re irreplaceable in the world of modern electric vehicles.
Moreover, a lithium-ion battery sold at the lowest price provides more energy per kilogram than the highest-priced lead-acid battery. This is due to the fact that it has an energy density of about 300-500 Wh/kg compared to the lead-acid battery, which has 25-35 Wh/kg.
Capacity
Compared to a lead-acid battery, a lithium-ion battery has a greater capacity as it’s capable of storing more electricity.
This means that if you were to travel the same distance by scooter you’d power with each of the two batteries, you’d need to recharge the lead-acid battery way sooner than the lithium-ion battery.
Efficiency rate
Again, a lithium-ion battery has higher energy efficiency than an equivalent lead-acid battery. This is due to its ability to convert energy from electrical to chemical energy during the charging process and reverse the same electrochemical process during the discharge phase.
To explain this using precise numbers, a lithium-ion battery is 95 percent efficient. In contrast, the amount of energy stored in an equivalent lead-acid battery that can be used is rated between 80 and 90 percent.
Also, a lithium-ion battery has considerably lower losses during both phases compared to a lead-acid battery.
Depth of discharge
A lithium-ion battery has a lower self-discharge compared to its lead-acid counterpart. This means that the chemical reactions inside of it decrease the energy stored in it less compared to those in an equivalent lead-acid battery.
Moreover, a lithium-ion battery has low self-discharge when it’s being used, but also when it’s just sitting on the shelf.
Also, holding a charge for a longer period of time contributes to lithium-ion batteries’ better storage life.
Size and weight
The compact and lightweight design of lithium-ion batteries is one of the major reasons why many electric vehicle owners prefer them over lead-acid batteries.
Compared to lead-acid batteries, they have smaller cells, are made of the lightest metal (lithium), and their electrolyte contains no water.
On the other hand, lead-acid batteries are made with one of the densest materials, lead, and have more cells and a water-based electrolyte.
Moreover, they require adequate ventilation so that they can release gasses into the atmosphere and don’t overheat in higher temperatures. So, it’s no wonder they’re bulkier and heavier than lithium-ion batteries.
Charge rate
Lithium-ion batteries charge faster than lead-acid batteries. It will take you 2 to 3 hours to fully charge a single lithium-ion battery pack. In fact, it can even take you less amount of time than that if you use modern quick-charging technology.
Moreover, a lithium-ion battery allows it to be partially charged as well.
A lead-acid battery of a similar capacity can take 8 to 9 hours to be charged. Besides, it’s not recommended that you partially charge this type of battery because if you do, this can cause sulfating, and thus damage it.
Installation
A lithium-ion battery is easy to install and replace on any electric vehicle due to its compact and lightweight design. Also, thanks to its sealed cells, this battery is leak-proof and can be effortlessly installed in any position.
As for lead-acid batteries, being bulky, they’re not that easy to install. Additionally, you need to be extremely careful not to install them in an upside-down position, as this can lead to leakage and cause problems with venting.
Maintenance
Both types of batteries require good maintenance to prolong their lifespan. However, lithium-ion batteries require less of it compared to lead-acid batteries.
A lithium-ion battery requires protection circuitry to prevent its cells from overcharging or discharging entirely when there’s an increase or decrease in the voltage or in high temperatures.
As for lead-acid batteries, their plates need to be de-sulfated to maintain their electrochemical reactions with the electrolyte. Also, their terminals require cleaning and the liquid electrolyte needs to be continually topped off with water.
Additionally, a lead-acid battery needs to be charged in a special area, as it gives off gas during charging. That gas needs to be released into the atmosphere by using a ventilation system specially designed for that purpose.
Cost
A lithium-ion battery is more expensive than an equivalent lead-acid battery. Usually, the extra price is well worth it, however, since the user experience overall is much better with lithium-ion batteries.
Lifespan
Lithium-ion batteries can endure a bigger number of discharging and charging cycles than lead-acid batteries without having their performance reduced.
That makes their lifespan almost twice as big in the general scenario with batteries of equivalent parameters.
If a lithium-ion battery is used and maintained properly, it can endure up to 3000 cycles. Even the best brands of lead-acid batteries can undergo 1200 to 1500 cycles, on the other hand.
Safety and environmental impact
Lithium-ion batteries are safer to use and more environmentally friendly than lead-acid batteries. Namely, the latter contain corrosive sulfuric acid, which can leak if the battery is overcharged. Also, both electrodes of lead-acid batteries are made of lead, and this poses the risk of lead contamination and toxic waste while they’re being produced, disposed of, or recycled.
If a lead-acid battery is overcharged, it may vent oxygen and hydrogen as well, which can cause an explosion. However, it’s noteworthy that although fires caused by this type of battery are possible, it’s been estimated that lead-acid batteries pose low fire risks.
However, science shows that this type of battery can be used safely and sustainably if certain precautions are taken. You can find more information about this on the link here.
Lithium-ion batteries, on the other hand, don’t pose these risks. However, they do have the disadvantage of being sensitive to high temperatures and being flammable. When the internal heat produced within the battery is greater than the heat dispersed into the atmosphere, this can lead to a condition known as thermal runaway. This can, in turn, cause the battery to explode.
Pros of lithium-ion batteries
- higher energy density
- greater capacity
- higher efficiency rate
- lower self-discharge
- compact and lightweight design
- faster charge rate
- easier to install
- doesn’t require frequent maintenance
- longer lifespan
- eco-friendlier
Cons of lithium-ion batteries
- can damage entirely if overcharged or over-discharged
- require internal circuitry system
- expensive
- sensitive to high temperatures
- flammable
Pros of lead-acid batteries
- good efficiency rate
- can produce a sudden surge of electricity
- rugged
- inexpensive
Cons of lead-acid batteries
- low energy density
- bulky and heavy
- take longer to charge
- can’t be partially charged
- harder to maintain
- short lifespan
Lithium-acid battery vs lead-acid battery: Which one is better for electric scooters?
When it comes to batteries in electric scooters, lithium-ion batteries will almost always be the correct choice thanks to their high energy density, compact and lightweight design, great capacity, and longevity.
Further, a lithium-ion battery can undergo many charging and discharging cycles and still its storage capacity and performance won’t be compromised. Also, it has a fast charge rate and can be charged both completely and partially.
Lead-acid batteries are commonly found in low-cost models, larger vehicles, and electric scooters for children as well.
