A guide to maintain EV lithium batteries. Differences between NMC and LFP chemistries

In a previous blog post we mentioned how and why li-ion batteries degrade and eventually fail but it did not make a distinction between specific battery chemistries. Your vehicle user manual will provide the best advise on how to maintain the battery for best “performance” based on their premises. However, there are subtle and particularly important aspects that will affect battery longevity and may initially seem contradictory. Let’s get on to it.

Despite there are an array of chemistries of Li Ion batteries, the two most common types used in the automotive industry are LFP and NMC:

Lithium Iron Phosphate (LFP or LiFePO₄)

Nickel Manganese Cobalt (NMC) 

Pros: High energy density, good balance of power and capacity
Cons: More expensive due to cobalt, lower cycle life than LFP, and more heat-sensitive
Common Uses: higher range EVs, portable electronics, grid storage 

These two chemistries dominate the market, with LFP growing in popularity due to cost and safety advantages, especially for EVs and energy storage. NMC remains preferred for high-performance applications where energy density is critical. So, what I can do to maximise their longevity and usability in the real world?

Realistic best practices for LFP type

Charge the battery to 100% and try to go below 30% at least once a month

This helps the battery computer maintaining accurate State of Charge (SoC) readings. The voltage curve of these batteries is quite flat and difficult to figure out how much energy is left.

Yes, it is true that cycling at higher SoC will degrade the battery further. However, it is also true that it will not be great to find out that your battery went flat when it was showing 30% left just a few minutes prior.

Try to cycle the battery at lower SoC in normal use

This is contradictory, you may think! However, having a low depth of discharge and doing it at the lower end of the SoC will avoid annoying degradation. As an example, do you daily commute between 20-50% for example. Charge it frequently, at low power and stop charging earlier.

Keep the battery lower than 50% SoC when not in use for a few weeks

For example, if you ago for a holiday and are leaving your car at the airport. Especially if it is during summer in Australia! In winter, this is not so critical.

Frequent and small discharging-discharge cycles is better than 1 single charge and full discharge to 0%. In other words, lightly charge after every trip if you can

Especially when it is extremely hot outside, or you have been heavy with the right foot. Let the battery cool down or make sure the active cooling system works as intended

Just like the LFP type, this will minimise degradation, especially at higher temperatures

It is great to be aware what factors affect battery longevity but do not panic. The vehicle’s battery management system (BMS) has already accounted for these variables as well as usability. For example, the BMS limits the charge current when fast charging in extreme conditions. In the same manner, the car avoids draining the battery below real 10% SoC to minimise cell damage and imbalances.

Car manufacturers usually offer longer warranties for batteries giving you confidence it will perform over time. Make sure you check the fine print as manufacturers specify performance and SoH threshold levels. In any case, there are smart safety measures built in the battery meaning it is difficult to do the wrong thing. The vehicle user manual will always give you the best advice but you can also call us and we will redirect you to our nearest approved Infinitev approved service centre.

Infinitev has service contracts with major vehicle manufacturers to repair their batteries during the warranty period. The repaired / refurbished unit meets the same or better specs than the battery that came out of the car before the failure. As more EV vehicles are going out of warranty, Infinitev will also have repaired and remanufactured batteries at a fraction of the original price, maintaining the vehicle value and brand reputation.