Prolonging the life of your battery

[ChrisB NZ]

Hi all,
Just wondering what strategies people use for prolonging the life of your batteries (if any)?

From what I've read, Lithium Ion batteries last a lot longer if they are not constantly charged up fully to 100%. If they are charged to only 80%, you get something like 2 or 3 times more charging cycles out of them.

You can buy specialised battery chargers which stop at 80%, but I'm not sure these support proprietary batteries from Shimano, Specilaized etc. A simple trick I use is to use a cheap timer on the power socket supplying the charger and set it to cut off after a certain time to give the battery less than a full charge. I also charge up to 100% every so often to allow the cells to be equalised/balanced by the battery management system.

 

[MartinW148]

Personally I charge directly after a ride and usually that means I have around 20-40% left, but I do charge back up to 100%. A timer plug is a good idea, especially if like mine you charge with the battery on the bike.

Not sure if they allow you a true 100% of the battery usage anyway so I don't think you can ever really charge to 100% (I know this is true of electric cars).

Honestly I'm not sure mine will get hard enough use for me to worry too much, but it would be interested to hear if age affects the battery as well as the number of cycles put through it.

 

[Donnie797]

Honestly I'm not sure mine will get hard enough use for me to worry too much, but it would be interested to hear if age affects the battery as well as the number of cycles put through it.

Yes it does. A two year old battery with only a handful charge cycles could be in a much badder condition than one that was constantly used. Very important is, that a battery should never ever lay around discharged - once it's "deep discharged" it's dead. If you don't use it regularly (or maybe over winter) the battery should be charged to 70-80% which is the healthy "storage load" and decreases the aging.

 

[eFat]

If they are charged to only 80%, you get something like 2 or 3 times more charging cycles out of them.

A charging cycle doesn't mean much. the battery won't stop after 500! But the remaining capacity will not decrease as fast if not charged to 100%.

But I would not bother with that...

 

[MartinW148]

Yes it does. A two year old battery with only a handful charge cycles could be in a much badder condition than one that was constantly used. Very important is, that a battery should never ever lay around discharged - once it's "deep discharged" it's dead. If you don't use it regularly (or maybe over winter) the battery should be charged to 70-80% which is the healthy "storage load" and decreases the aging.

Well aware that a battery should never deep discharge. Used to have a motorbike which sat on a smart charger over the winter.

I was wondering how batteries would be affected say, 500 charges over 2 years compared to 500 charges over 5 years.

 

[Donnie797]

Well aware that a battery should never deep discharge. Used to have a motorbike which sat on a smart charger over the winter.

I was wondering how batteries would be affected say, 500 charges over 2 years compared to 500 charges over 5 years.

Well with the same amount of charges, the 2 year old battery will of course be "fresher" than the 5 year old. There's usage-dependend-aging and usage-independent-aging (like calendar-aging, storage-temperature, storage-load, etc.).

I wouldn't break my mind too much on it - but if you want to dive into details, there are many studies related to li-ion battery-aging in e-cars out there - like this (do a google search on "li-ion battery aging" for dozens more).

 

[ChrisB NZ]

Thanks for the comments guys. I had a look at that dissertation Donnie797 - but didn't read the whole thing

I guess there are things that you can do to prolong battery life but maybe not worth the hassle. Let's face it - at one charge per week, 500 charges is 10 years. And in 10 years there will probably be new battery technologies available. It will be interesting to see how long these batteries last though.

 

[Donnie797]

yes true - you definitely won't kill the battery with the amount of charges, before this happens the capacity will shrink just because of calendar-aging. Just follow the tipps in the manual to have it at it's best possible health as long as possible.

 

[Dax]

Something I've not seen discussed so far is storage in warm places when fully charged. I know this can have a significant impact on the life of lipo, I assume the same is true for lion. The obvious way this could happen is being stored in a locked car or van in the summer sun.

 

[Donnie797]

Yes, temperature is one of the bigger aging-factors in those studies. But i wonder if e-car manuals recommend to "not park the car out in the sun"? Would be interesting to read a study comparing e-car battery life in sunny california with not-so-sunny england.

If possible i always park my bikes (also the non-e) in the shadows when the sun is burning, it's better for the paint, stickers, plastics, etc..