Shimano Battery Life Poll

[electricbogaloo]

Of course, the fact that now pretty much every ride is taking the battery from 100% - 0% probably isn't helping?

No, definately not. Doing deep discharges should only be avoided and only be done when you have to cover the distance in a certain assist mode.

It's very noticeable that none of my Bosch equipped friends are experiencing similar problems in the cold though, or at least to nothing like the same extent.

What's weird is that to some extent Bosch-Users must experience the same behaviour in principal. All lithium-ion batteries work like that and as far as I know they use similar cells.

Battery has never been below 20%

That's good.

and normally charged up to 80 - 90 % and 100 just prior to a longer run.

That's not ideal. Lower storage soc is beneficial to battery health. High storage soc lets it degrade faster, especially under high temperatures. But empty soc is worst. So it's a bit tricky but storing it around 30% @ 10-15 degrees depending how much energy the bms drains should be ideal.

 

[Growmac]

No, definately not. Doing deep discharges should only be avoided and only be done when you have to cover the distance in a certain assist mode.

I tend to use Eco as much as possible, but I bought the bike to ride it. Nobody would say that a mobile phone battery being 'dead' (<80% capacity and processor throttling to prevent cutout) in 3 months would be acceptable, and the batteries in these bikes are much, much more expensive.

 

[electricbogaloo]

Well in my family my father ruin batteries of phones, notebooks or campervans all the time because they have that petrolhead attitude of thinking if its running empty its fine. Just charge it up the next day when you need it.

Not every battery dies completely but usually my notebook batteries while being older usually last longer then theirs.

You can emtpy it for sure if you immediately charge it. If it sits around like that for a longer time it will degrade faster and can die off completely if it's cold or you do it all the time.

 

[nosenada]

From my experience with four different e8035 batteries the rapid decline in battery health is not a matter of battery abuse or misuse.

All four of my batteries have declined in almost exactly the same fashion regardless if I stored them at 40-60% or charge them to 100% after riding. All of the batteries declined to either 90% or 89% around 10 cycles, 87% at 20 cycles, and 85% or 84% at 30 cycles. So far I have only reached 40 cycles on one battery and it dropped to 82%.

Two of my batteries were replaced under warranty (at 85% and 82% health) and I no longer have them.

None of these batteries are or were over 6 months old and declined between 13 to 18%!

My wife's e8010 battery by contrast is about 1 year old, at 14 cycles, and at 98% health which seems more reasonable.

 

[TG1971]

From my experience with four different e8035 batteries the rapid decline in battery health is not a matter of battery abuse or misuse.

All four of my batteries have declined in almost exactly the same fashion regardless if I stored them at 40-60% or charge them to 100% after riding. All of the batteries declined to either 90% or 89% around 10 cycles, 87% at 20 cycles, and 85% or 84% at 30 cycles. So far I have only reached 40 cycles on one battery and it dropped to 82%.

Two of my batteries were replaced under warranty (at 85% and 82% health) and I no longer have them.

None of these batteries are or were over 6 months old and declined between 13 to 18%!

My wife's e8010 battery by contrast is about 1 year old, at 14 cycles, and at 98% health which seems more reasonable.

I’m sure it’s weight related I noticed same my battery is 87% after 26 charge cycles my wife is at 99% after 29 cycles, she has had her bike a month longer but we have done same rides stored and charged batteries in same place only difference is she rides in all modes and I ride in eco and I am 12kg heavier.

 

[nosenada]

I’m sure it’s weight related I noticed same my battery is 87% after 26 charge cycles my wife is at 99% after 29 cycles, she has had her bike a month longer but we have done same rides stored and charged batteries in same place only difference is she rides in all modes and I ride in eco and I am 12kg heavier.

Or you have the same defective cells and/or BMS that the e8035 has in your e8010 battery and your wife and my wife does not.

 

[TG1971]

Or you have the same defective cells and/or BMS that the e8035 has in your e8010 battery and your wife and my wife does not.

Maybe ?

 

[Growmac]

You can emtpy it for sure if you immediately charge it. If it sits around like that for a longer time it will degrade faster and can die off completely if it's cold or you do it all the time.

I keep it indoors in the warm when not riding.
I never, ever let it sit empty.
Whenever I can I take it back up to about 60% and only top off just before I ride. If not practical then it'll be charged to 100% (why do the chargers not let you select a charge state?).
I keep it in the car and not on the rack if driving.
I ride mostly eco.
I pedal hard.
I use at least 80% of the battery, and not infrequently 100%, most rides because I bought an ebike to enable large rides! It's interesting that a number of people describe identical degradation though. TG1971 above precisely describes the pattern my battery followed.

 

[Dave_B]

This is mine.
Ignore the distance, it’s a new motor

 

[Dave_B]

It’s an 8035 battery.

 

[TG1971]

This is mine.
Ignore the distance, it’s a new motor

View attachment 47307

How much do you weight if you don’t mind me asking ?

 

[Dave_B]

85KG

 

[TG1971]

I’ve said this already on here but I’m sure it’s the weight of the rider I’m same weight as you ish and my battery now 86% after 28 cycles my wife 70kg in riding gear same mileage same rides as me but the battery health is 99%.

 

[jimbob]

Are they the same battery?

All the E8035 batteries on here have shown exactly the same pattern.

 

[TG1971]

Are they the same battery?

All the E8035 batteries on here have shown exactly the same pattern.

Same full suspension bikes, hers small, mine large, same e8010 battery and e8000 motor

 

[rikioh]

Could this be some kind of Battery Firmware Bug on the 8035 Battery? Cause i don't think they use other Cells in other Batterys...

 

[Spiff]

Could this be some kind of Battery Firmware Bug on the 8035 Battery? Cause i don't think they use other Cells in other Batterys...

My last theory isthat the internal battery could overheat because of it being in a closed tube in the frame. External batteries have better behaviour and they have very good cooling outside the frame.

 

[jimbob]

My last theory isthat the internal battery could overheat because of it being in a closed tube in the frame. External batteries have better behaviour and they have very good cooling outside the frame.

Are the external batteries housed in plastic? The internal ones are ali, so will have a good heatsink even though in the frame. I've also not noticed the battery being hot after a ride.

Doesn't mean it's not an issue though.

 

[jimbob]

Could this be some kind of Battery Firmware Bug on the 8035 Battery? Cause i don't think they use other Cells in other Batterys...

Somthing I'm planning to test out. I've got a new battery on order so will test the capacity difference between that and my old one by measuring the power required to charge from flat. It should at least give an indication if the reported degradation is real or not.

 

[Spiff]

Are the external batteries housed in plastic? The internal ones are ali, so will have a good heatsink even though in the frame. I've also not noticed the battery being hot after a ride.

Doesn't mean it's not an issue though.

The majority of failing batteries are internal ones, external behave much better, mine is stellar, 98% after 42 cycles and 3800Km. And I do not think Shimano is using different cells or BMS, it is just a different repack.

Some bike manufacturers may improve cooling of the internal battery by having air inlets that force air through battery sides but others may have a closed box that is not letting the air cool the batteries.

 

[TG1971]

The degradation must be real as most of us on here are losing range as the % goes down

 

[TG1971]

The majority of failing batteries are internal ones, external behave much better, mine is stellar, 98% after 42 cycles and 3800Km. And I do not think Shimano is using different cells or BMS, it is just a different repack.

Some bike manufacturers may improve cooling of the internal battery by having air inlets that force air through battery sides but others may have a closed box that is not letting the air cool the batteries.

My external is not doing so good as previous posts

 

[Spiff]

My external is not doing so good as previous posts

OK, so my theory is not valid in your case.

 

[jimbob]

The degradation must be real as most of us on here are losing range as the % goes down

I would agree it seems to be the case, but would be good to confirm. Mainly for the E8035 battery where they all seem to show exactly the same pattern, which points to it being possible that its firmware. The external batteries seem so show different rates of degradation which would be more in line with some batteries failing faster than others.

ETA; Just trying to get some facts rather than speculation!

 

[TG1971]

OK, so my theory is not valid in your case.

It doesn’t seem to be, mine and wife’s bike are the same, charged the same, stored batteries same, same rides, mine 86% now after 27 cycles the wife’s is 99% only difference is weight, put wife’s battery on my bike and range back to what I got when bike new in august use my battery and range well down

 

[jimbob]

It doesn’t seem to be, mine and wife’s bike are the same, charged the same, stored batteries same, same rides, mine 86% now after 27 cycles the wife’s is 99% only difference is weight, put wife’s battery on my bike and range back to what I got when bike new in august use my battery and range well down

Do they both show the same number of discharge cycles? That could show if weight was a factor as there would be more cycles on one than the other if more power was being used due to increased weight.

 

[Spiff]

It doesn’t seem to be, mine and wife’s bike are the same, charged the same, stored batteries same, same rides, mine 86% now after 27 cycles the wife’s is 99% only difference is weight, put wife’s battery on my bike and range back to what I got when bike new in august use my battery and range well down

Well, in this case with same bike, motor, battery, the only different parameter between both batteries is the rider. I suppose that your wife is thinner than you, so could it be that you use more juice from the battery and deep discharge it? Deep discharge and storing the battery with low charge level could degrade it more rapidly. I am sorry if you already posted this information, but I could not find it.

 

[TG1971]

Do they both show the same number of discharge cycles? That could show if weight was a factor as there would be more cycles on one than the other if more power was being used due to increased weight.

the wife’s bike has more cycles 29 for hers 27 mine due to having it 3 weeks longer

 

[electricbogaloo]

Well, in this case with same bike, motor, battery, the only different parameter between both batteries is the rider. I suppose that your wife is thinner than you, so could it be that you use more juice from the battery and deep discharge it? Deep discharge and storing the battery with low charge level could degrade it more rapidly. I am sorry if you already posted this information, but I could not find it.

Yes a heavier rider will stress the battery more and discharge it faster to a level were it ages faster. Also the integrated batteries will get warmer than an external one, even if it's aluminium.

 

[TG1971]

Yes a heavier rider will stress the battery more and discharge it faster to a level were it ages faster. Also the integrated batteries will get warmer than an external one, even if it's aluminium.

I am 13kg heavier than my wife so do use more battery on the same ride, we do charge back to 70% as soon as finished on ride or 100% if going back out next day, I think 14% degradation is unacceptable after 27 cycles of battery but company I bought it off think it is and won’t warranty it, we bought them to do big natural rides I guess they will be getting shorter ha ha I may get another but I don’t spend £600 if battery is not going to last, thanks your input ?