Loss in battery life

Akiwi

🐸 Kermit Elite 🐸
Feb 6, 2019
986
1,286
Olching, Germany
What is your experience in battery range drop off over time?
I have had my current ebike for 1 1/2 years now, and have done over 3800 KM on it. Yesterday I did a ride where I arrived back at the car with a very nearly flat battery even though I was mostly in eco or Tour on the ride. I am sure I could get a lot more range out of the battery last summer when it wasn new.
What sort of drop off are you experiencing?
Battery is always stored inside in winter, and I normally keep it fully charges so I can jump on the bike any time and not worry about the battery running out on me.

I am asking as I am planning a trans Alp tour later this year and range / health of the battery is very important!
 

Lee Dove

Well-known member
Oct 12, 2018
301
268
Scotland
They talk about a battery having 300 cycles before losing efficiency (some companies guarantee this) si I would guess you have more cycles than this. Mabe time for new battery and keep the old one as a spare.
 

jerry

Active member
Dec 22, 2018
257
165
Belgium
I agree there is a difference between marketing promises and real-life capacity, despite following all storage/charging/emperature instructions militantly.
My 3000km-pack has considerably less capacity than my 1000km-pack, even though, with less than 100 full cycles equivalent, it should still be as good as new.

I did notice the indications to change over time too, though. Newer battery seems to indicate "full" bars longer, the next bars then seem to follow more rapidy. The older pack drops the Full bar much quicker, but seems to be holding on to the next bars longer.
 

outerlimits

E*POWAH BOSS
Founding Member
Feb 3, 2018
1,241
1,574
Australia
I’ve done 5659km in 14 months. Was a 504wh battery and capacity is now down to 459wh. 91% battery health and it’s done 116 full charge cycles.

What are these bars you speak of ?
 

MattyB

E*POWAH Elite World Champion
Jul 11, 2018
1,266
1,279
Herts, UK
What sort of drop off are you experiencing?
Battery is always stored inside in winter, and I normally keep it fully charges so I can jump on the bike any time and not worry about the battery running out on me.
There is your problem - storing at full charge is probably the quickest way to reduce capacity and cycle life in a Lithium pack. Best practice is to store at between 30-70% charge, never 100% if leaving for any length of time (>24hrs).

How to Prolong Lithium-based Batteries - Battery University

Three Ways That Lithium Dendrites Grow
 

MattyB

E*POWAH Elite World Champion
Jul 11, 2018
1,266
1,279
Herts, UK
They talk about a battery having 300 cycles before losing efficiency (some companies guarantee this). I would guess you have more cycles than this. Mabe time for new battery and keep the old one as a spare.
That can’t be true in this instance - if it were he’d only have been getting an average range of 3800/300 = 12km per full charge. This pack has been given an early bath through prolonged storage at an elevated state of charge (SOC); unfortunately when treated like that there is very little chance of it reaching it’s designed cycle life.
 

Lee Dove

Well-known member
Oct 12, 2018
301
268
Scotland
That can’t be true in this instance - if it were he’d only have been getting an average range of 3800/300 = 12km per full charge. This pack has been given an early bath through prolonged storage at an elevated state of charge (SOC); unfortunately when treated like that there is very little chance of it reaching it’s designed cycle life.
That can’t be true in this instance - if it were he’d only have been getting an average range of 3800/300 = 12km per full charge. This pack has been given an early bath through prolonged storage at an elevated state of charge (SOC); unfortunately when treated like that there is very little chance of it reaching it’s designed cycle life.
That can’t be true in this instance - if it were he’d only have been getting an average range of 3800/300 = 12km per full charge. This pack has been given an early bath through prolonged storage at an elevated state of charge (SOC); unfortunately when treated like that there is very little chance of it reaching it’s designed cycle life.
Ah I forgot it is FULL charge cycles not just charges .
 

MattyB

E*POWAH Elite World Champion
Jul 11, 2018
1,266
1,279
Herts, UK
Ah I forgot it is FULL charge cycles not just charges .
Correct. I do have some sympathy with the OP here though - the instructions for most ebikes when it comes to battery usage and care are absolutely woeful. A cynic might even suggest they are hoping you will store your battery at full charge and kill it early so they can sell you a new one... :unsure:
 

Akiwi

🐸 Kermit Elite 🐸
Feb 6, 2019
986
1,286
Olching, Germany
Correct. I do have some sympathy with the OP here though - the instructions for most ebikes when it comes to battery usage and care are absolutely woeful. A cynic might even suggest they are hoping you will store your battery at full charge and kill it early so they can sell you a new one... :unsure:
Well, I didn't know that keeping it full was so bad. However I have read that about 40 - 60% is the optimum level to keep it charged. But there is nothing worse than wanting to jump on your bike for a tour and finding that the battery is almost empty!! How do you guys do it that you keep your batteries half full for storage?
 

MattyB

E*POWAH Elite World Champion
Jul 11, 2018
1,266
1,279
Herts, UK
Well, I didn't know that keeping it full was so bad. However I have read that about 40 - 60% is the optimum level to keep it charged.
...How do you guys do it that you keep your batteries half full for storage?
60-70% is not really "almost empty" - for most current bikes it would takes around an hour or slightly more to get from there to fully charged, and for a lot of peoples riding 70% range would be enough to complete their average ride anyway. Having used lipos in RC for many many years now charging the night before or on the morning I go flying is absolutely standard for me, so this is no major inconvenience. Ultimately it is the owners choice - charge to full for convenience but kill the pack prematurely, or leave at the correct storage level and accept the need to plan a bit better.
...But there is nothing worse than wanting to jump on your bike for a tour and finding that the battery is almost empty!!
Personally I would say there is nothing worse than having to shell out £500-1000 on a new battery ~18 months and ~300 cycle too early, but maybe I am just tight... ;) YMMV.
 
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Akiwi

🐸 Kermit Elite 🐸
Feb 6, 2019
986
1,286
Olching, Germany
60-70% is not really "almost empty" - for most current bikes and charger it would takes around an hour or slightly more to get from there to fully charged, and for a lot of peoples riding 70% range would be enough to complete it anyway. Having used lipos in RC for many many years now charging the night before or on the morning I go flying is absolutely standard for me, so this is no major inconvenience. Ultimately it is the owners choice - charge to full for convenience but kill the pack prematurely, or leave at the correct storage level and accept the need to plan a bit better.

Personally though I would say there is nothing worse than having to shell out £500-1000 on a new battery ~18 months and ~300 cycle too early, but maybe I am just tight... ;) YMMV.
Nope not tight. I hate that too. I'd much rather spend the money on something constructive... like beer or somahing ;)

I guess I will have to start planning better. I am off to Lake Garda for 3 weeks of biking and Surfing next week, and am a little concerned if my battery will be up to some of the tours I have planned.
1600 vertical and 50KM is pretty standard there.
Sometimes more sometimes less.
 

Akiwi

🐸 Kermit Elite 🐸
Feb 6, 2019
986
1,286
Olching, Germany
I did a firmware update on my system and got them to read my Battery status.
Was surprised to see it is rated as having only 55 full charge cycles.
Not bad for 4000 KM me thinks. that means an average of 72 KM per full charge, ignoring vertical meters. Guess that sounds ok.
Apparently Bosch sais that after 500 full charge cycles, the battery should still have 75% of its full charge.
 

MattyB

E*POWAH Elite World Champion
Jul 11, 2018
1,266
1,279
Herts, UK
...Apparently Bosch says that after 500 full charge cycles, the battery should still have 75% of its full charge.
Only if you don't store it at full charge and higher temps. They are pretty clear on the factors that affect life on their site...

1561552602472.png


The eBike battery: long range, low weight, easy to charge
 

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