Subaru Forester e-Boxer battery pack – how long it last

Some may have doubts towards hybrid cars. Specially now when the e-Boxer concept is the first iteration for Subaru that they have launched in Europe. Does it work properly and how long the battery pack will last? How much battery pack cost to replace?

Personally I am confident towards the e-Boxer technology that there will be no problems or issues and even if there would be, Subaru can handle those.

The e-Boxer is so new that there is no existing evidence that users would tell by experience that what type of issues they might have or was there issues at all. We need to wait years before receiving any feedback from actual owners.

E-Boxer was launched in the Europe in early 2020, however it was already sold in Japan from 2019. So it has been in domestic markets for a year before launching it on other markets.

So at least Subaru had some time to fine tune their system, before delivering it to Europe. Otherwise e-Boxer is not that much different from the regular Forester.

Battery guarantee

Based from the experience of other brands, such as Toyota, they have not replaced batteries in large scale.

Once I heard a joke regarding the Toyota’s hybrid system. They have changed only 2 battery packs in their cars ever produced. That’s pretty amazing considering how many million cars they have manufactured!

First changed battery pack was for research purposes and the second one was changed accidentally. The battery pack was not faulty at all!

That was really humor but still gives an idea that battery packs in general are very robust and reliable.

Besides even Toyota does not manufacture battery packs itself, they acquire batteries from other companies. Mainly from Panasonic. Globally there are some other hybrid battery suppliers too.

This is the case also with Subaru. They do not manufacture batteries, hence it is something that they have not just developed. So they are using technology which has been existing many years and decades already.

Subaru gives 96 months (8 years) / 160 000 km (100 000 miles) guarantee for the battery pack. Depending which of these criteria fulfills first.

Guarantee gives me confidence that if there would be problems, those are fixed as well.

Estimated lifespan of the battery pack

According to Subaru they expect battery to start slowly lose it’s performance after 10 to 15 years of use. This might be close to truth as well, if we compare performance to other hybrid or electric cars too. Many years ahead before we see any deterioration.

There are many factors that affects to the battery pack life expectancy. E.g. environmental temperature, where the car is being used. Higher temperatures has a negative impact to the lifetime.

On the other hand too cold has a negative impact too and battery pack refuses to work in the first place. Everything below -20C is considered to be “too cold”.

Technical details available e.g. from Wiki which explains hybrid battery operating temperatures in detail:

Keep in mind that Subaru Forester e-Boxer uses Lithium-ion type of battery packs.

Subaru has also a Battery Management System (BMS) implemented on the e-Boxer. This system guards battery pack so it will not be fully charged or completely discharged either. As this would have a negative impact on the battery lifespan.

Owner / drive does not need to worry about operating the BMS. Everything will happen on the background.

On wikipedia BMS is also explained pretty deeply. So for those who are interested of more technical details more, I suggest to check that link.

Battery replacement

If the battery really needs to be replaced, you can buy a new one from Subaru. Or if that happens during the guarantee period, you would get one for free from Subaru.

Authorized service will help you with these cases. Estimated price (by Subaru) for a new battery pack is somewhere between 1000 – 3000 euros.

On the internet there is many articles and videos advising whether you can or cannot repair battery packs by yourself. Some of the articles are saying that it is not technically possible and some says that you can even swap individual cells inside the battery pack.

Generally speaking I would recommend to contact authorized service rather than doing itself. This is of course depending of your personal knowledge and skills. You need to remember that it is also a safety issue.

There is always risk associated when doing electricity related work. Secondly quality of your work can be a risk later. Can you really be sure that everything works after a while too.

So please do not do any adjustments or repairing by your own, please contact service always.

What can owner do to increase battery life

Answer is simple. There is not that much from the owner’s point of view what can be done to increase battery lifetime.

Only thing what comes to my mind is that avoid not using car for longer period (several months). That can discharge the hybrid battery so that Battery Management System is not able to take care of the charging levels and therefor possibly shorten lifetime of battery.

My recommendation is to use car regularly, so it will be in good condition. Forester loves it when it is being used.


  1. Hi,

    Your blog/website is extremely useful to new and would-be owners and I have learned many things from your posts. I have just gotten an E-boxer and am curious on the charging behaviour of the hybrid battery. I would leave my car overnight with the hybrid charge at around 3 bars (slightly less than half of the full meter range) and when I start the car the next morning, the bar will be empty. Is this normal. I suspect that the battery charge indicator is not linear and half of the meter does not indicate half charge. I stay in the tropics so the temperature is seldom below 23 C. I have the car less than a week so I am not sure if longer usage would ‘normalise’ the battery behaviour.

    I do not know of any eboxer owners so I am reaching to the most experience one I know – you .

    Thank you for the very many informative blogs.


    1. Thank you for the feedback. Very good viewpoint and question. To be honest that is something I have not thought earlier. I would assume it is normal and nothing to be worried about. I will update later how it behaves on my car.

      Meter will not be full anyways, as car protects battery by not charging fully. Similarly it will be never be totally empty. With that battery has a long lifecycle. I would say that meter is not that accurate and gives driver just rough idea of the charge.

      Congrats of the new car! After one year of driving I still like my car very much.


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