chriswestberks
Posts: 3
Joined: Mon May 15, 2017 12:30 pm

Battery life if run battery down on daily commute (REX)

Mon May 15, 2017 12:37 pm

Hello, I've just accepted a new contract with a daily commute which requires me to exhaust the battery and finish the last 20 miles on the return leg on REX. I understand this would shorten the battery life on most EVs, but the i3 reserves about 20% of the battery which can never be run down by normal driving. Nevertheless, would this daily commute likely shorten my battery life?
Thanks, Chris

jadnashuanh
Posts: 3445
Joined: Thu May 22, 2014 2:07 pm
Location: Nashua, NH USA

Re: Battery life if run battery down on daily commute (REX)

Mon May 15, 2017 4:25 pm

IMHO, in the short answer, yes...but, by how much, that's hard to say. BMW's battery warranty, at least in the USA is 8-years, or 100,000-miles...it must still hold at least 70% of a new pack's capacity. The battery tech in the i3 is not the same as a typical cellphone's. They are designed for much longer life and the charging logic is much more complex to aid in that result.
Jim DeBruycker
2011 535i x-drive GT, 2014 i3 BEV


bmwquickspeed
Posts: 7
Joined: Thu Apr 13, 2017 9:51 am

Re: Battery life if run battery down on daily commute (REX)

Thu May 18, 2017 11:18 am

Another option would be to code your car so you have full control of the REX and then just turn it on early so you're not bringing the battery so low everyday.

Nobody really know what will happen yet in the long run but personally I believe that bringing the battery down to that low of a charge on a daily basis would be bad for the battery in the long run even though BMW does have a buffer built in.

chriswestberks
Posts: 3
Joined: Mon May 15, 2017 12:30 pm

Re: Battery life if run battery down on daily commute (REX)

Tue May 30, 2017 5:50 am

Bmw confirmed on the phone this would shorten battery life, which makes sense. I am turning on the Rex at about 25% of viewable capacity

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