Today the spread of electric cars continues its rise, but among the doubts that haunt consumers regarding the purchase of green cars are those on the duration of the batteries : Ni-Mh and Lithium, which is better?
And above all, how long can they last ?
Vehicle battery life
Are electric cars a worthwhile long-term investment? One of the aspects to keep in mind when choosing whether to buy one is certainly the battery life .
The doubt is valid for both electric and hybrid cars , in short, for any type of car whose operation depends (even in part) on accumulators.
The life of automotive batteries depends on 2 different factors, closely linked to each other, namely:
- the technology used
- the capacity and duration over time
In general, with today’s technology we can say that a normal lithium vehicle battery lasts about 8 years , and that the replacement of the battery pack costs practically as much as a new compact vehicle with a traditional internal combustion engine. But which are the best batteries?
Ni-Mh or Li-ion automotive battery?
As mentioned, the useful life and duration of an automotive battery depend on the technology used: to date, the most common accumulators are Ni-MH (nickel metal hydrides) and Li-ion (lithium ions).
The latter is the preferred technology, thanks to the lower volume and weight for the same amount of stored energy, and the lack of “memory effect”, that is the reduction of the capacity to store energy in the event of recharging with the battery not discharged.
On the other hand, Li-ion batteries have a progressive (unstoppable) decline in performance, and everything is worsened by thermal changes: at temperatures below -10 ° C and above all above + 30 ° C, these accumulators “suffer” and decrease their residual “life”.
How to extend the life of automotive batteries
To make the batteries last as long as possible, the manufacturers of electric cars are supported by electronics, which intervene to better regulate the charging processes: the lower the DoD (Depth of Discharge) depth of discharge, the longer the accumulator will last. Furthermore, the life of the Li-ion batteries is extended by frequent recharging, but only if calibrated by the control unit.
Remember that harmful exposure to high temperatures also occurs in “fast” charging stations , due to the high voltage used: but always charging using (on the contrary) a low voltage, will in any case reduce the capacity of the battery, while prolonging its useful life .
In practice, the batteries can also last longer, but they hold less charge, and this directly affects the performance of the vehicle (range, power, etc.).
How do the houses intervene? In addition to exploiting the control units, manufacturers use increasingly advanced cooling systems : for example on the Tesla (but also on the Renault Zoe and other cars) a type of liquid battery cooling has been studied that is capable of maintaining maximum 200,000 km) the capacity of the accumulator.