Gradual Battery Degradation

[Ron]

I have a 2019 Turbo Levo Comp Carbon which I have owned for about a year and put a little over 1200 miles on it. At 100% charge my battery has gone from over 500wh to now 477wh according to the BLEvo app I use. Is this normal degradation of lithium ion batteries or something I should be concerned about? I have only once come close to running out of battery support on a ride but with awareness of the low battery level still made it back with 12% - please let me know your experience. I don’t want this trend to accelerate so I end up with a 400wh battery instead of a 500.

 

[silverstone]

I personaly find this very realistic.
I come from another sport, where lithion polymere batterys live for around 20 cycles and then they're practically gone!
So a loss of around 5% of the capacity after around 1200miles is for me very good indeed

 

[apac]

Realistically expect capacity to lower by 20% after 400-500 full cycles. 5% as said above sounds normal. Sounds like you done at least 120 battery cycles... at a guess.

 

[magnil]

Stupid question maybe but is it that every cell gets a little lower capacity or is it that some cells give up (and could be replaced by an expert)?

 

[outerlimits]

2018 Levo with 504wh battery, 6948km
Battery health: 456wh after 138 charge cycles.

 

[apac]

Stupid question maybe but is it that every cell gets a little lower capacity or is it that some cells give up (and could be replaced by an expert)?

Cells eventually suffer from internal resistance which comes about from use and age. All the cells in the pack will naturally get this. Internal resistance can stop the motor from pulling the amount of amps needed and cause voltage sag and performance of the cell is reduced, but capacity of the cell is also affected. It’s just the nature of the chemistry in these cells. Too much heat can cause it and trying to use the cell too hard, but age and cycles eventually play as much part as anything else.
It’s never a good idea to just replace one or two cells as the internal resistance will be different from the others which can cause imbalances between cells as you charge and discharge them. You want the cells all the same age.

 

[Ron]

Thanks guys, makes sense and puts my mind at ease

 

[HikerDave]

I have a 2019 Turbo Levo Comp Carbon which I have owned for about a year and put a little over 1200 miles on it. At 100% charge my battery has gone from over 500wh to now 477wh according to the BLEvo app I use. Is this normal degradation of lithium ion batteries or something I should be concerned about? I have only once come close to running out of battery support on a ride but with awareness of the low battery level still made it back with 12% - please let me know your experience. I don’t want this trend to accelerate so I end up with a 400wh battery instead of a 500.

It’s inevitable but the rate of decline reduces as the battery ages. A battery is like a person, I guess.

 

[MattyB]

As above I think that level of degradation seems about what I’d expect, but the rate of degradation will depend on a number of factors about how it is stored and used, some of which are on the owners control, some of which aren’t - storage voltage, time stored at peak state of charge, ambient temperature, discharge rate etc.

Lots of threads on this topic are available in the forum, have a gander...

Battery Life extension. - EMTB Forums
Battery care/management - EMTB Forums
Loss in battery life - EMTB Forums
Battery Management - EMTB Forums

...and here's some external resources explaining the factors that influence cycle life, capacity degradation and power density over time...

How to Prolong Lithium-based Batteries - Battery University
Three Ways That Lithium Dendrites Grow

 

[MattyB]

Realistically expect capacity to lower by 20% after 400-500 full cycles. 5% as said above sounds normal. Sounds like you done at least 120 battery cycles... at a guess.

I think 400-500 cycles with only 20% capacity loss is probably optimistic unless you are very diligent at storing between 30-70% charge and your ambient temperatures are low. I would expect more like 250-300 cycles before replacement is needed.

 

[Zimmerframe]

My Kenevo's now on 298km's. 12 charge cycles. @Ron how many charge cycles are you showing ?

Fully charged Blevo shows 488wh, but heath still shows as 100%, so as @khorn has said, he thinks they've changed that so it just always says 100% ....

The average is increasing slightly as I try and stretch out range with eco 20/20 and trail 45/45. It was 24km's per cycle, it's now almost upto 24.8km's per cycle.

I'm pretty sure my battery is defective though and am trying to prove this (to spesh and myself).

I did 15k's (600m) yesterday on a mix of modes when I bumped into two other guys on normal bikes. Blevo said I had 8km's left in Trail. So I rode with those guys for another 23k/800m but mainly had to use Eco on steeper climbs and the power off anywhere it wasn't majorly difficult, but still ran flat 5k from home and at the lowest point on the ride

 

[Simoto123]

Hi, i Just checked my battery health on blevo.
I have 495 w/h and 98%, that’s with 1900 miles And 53 charges. This battery was new only a few weeks ago! I have a standard daily route of almost exactly the average per charge. I arrive home with 10/15 percent remaining. wind direction seems to make the difference. I haven’t noticed any degradation yet.
My settings are 35/100, 70/100, 100/100. I rarely use trail or turbo tending towards using gears rather than extra assistance. No rush eh?

 

[Simoto123]

For extra info I haven’t used my trailwatts with this battery as much lately. I save it for longer days. When I do use it the remainder is normally 40 ish percent over the same route. A hidden benefit of the trailwatts is that the “fresh battery feel” will last that mileage. Requiring no turbo or trail use at all. Trail days out with some shuttling works out very similar to be honest.
I am pretty light at 70 kg, bike is a 18 sworks Levo.

 

[TrailwattsUK]

For extra info I haven’t used my trailwatts with this battery as much lately. I save it for longer days. When I do use it the remainder is normally 40 ish percent over the same route. A hidden benefit of the trailwatts is that the “fresh battery feel” will last that mileage. Requiring no turbo or trail use at all. Trail days out with some shuttling works out very similar to be honest.
I am pretty light at 70 kg, bike is a 18 sworks Levo.

Great to hear ?

 

[davarello]

One factor you can control is the depth of discharge - using up 80% or more of the capacity every ride will reduce the capacity a lot quicker than staying in the top two thirds - so to maximise battery life either ride less distance , use less assistance or just get bigger battery like I'm planning to do !

No doubt the capacity on my bike has dropped over a year, but I'm still getting home with the same power left, so I must just be getting fitter.

 

[wepn]

One factor you can control is the depth of discharge - using up 80% or more of the capacity every ride will reduce the capacity a lot quicker than staying in the top two thirds..

Absolutely also it's isn't necessary to always charge to 100% if you don't need the full range or if you do charge to 100% do so before you ride not after. Not sure when balancing starts with this BMS but probably at 100%. Ideally left or stored at 40% up to 50% SOC.[WRONG] the Manual says 30% to 39%

Another option to increase cell longevity at the expense of double charge time is to use the 2A Travel Charger but that doesn't seem to be available any more.

 

[rsilvers]

A 700Wh battery that has degraded to 70% is still about as much capacity as a new 500Wh.

 

[rsilvers]

The Giant charger can do a 60% storage charge. Can the Turbo Levo charger stop at less than 100% capacity?

 

[wepn]

A 700Wh battery that has degraded to 70% is still about as much capacity as a new 500Wh.

True but still 700 grams heavier.

The Giant charger can do a 60% storage charge. Can the Turbo Levo charger stop at less than 100% capacity?

It can if you stop it yourself but absolutely right excellent point Specialized needs this. I can already do this with a Cycle Satiator but apparently that would void my warranty ironically by extending the pack longevity.

 

[rsilvers]

$12 at Amazon. I will get it.

 

[MattyB]

One factor you can control is the depth of discharge - using up 80% or more of the capacity every ride will reduce the capacity a lot quicker than staying in the top two thirds - so to maximise battery life either ride less distance , use less assistance or just get bigger battery like I'm planning to do !

That's true in absolute terms for a Li chemistry battery without a BMS. However, I've talked to representatives from Bosch and Shimano at shows in the last year; both confirmed the BMS cut-off point at "0% charge" are well above the levels that damage will occur (generally considered to be anything below ~3.1V/cell). For that reason I would not worry about "deep" discharging; prolonged storage at elevated SOC is likely to be a much more significant effect that reduces capacity and cycle life if you charge to full after every ride, especially in hotter climates.