Shimano Battery Life Poll

[Stuart569]

1) # of charging cycles See below
2) remaining capacity See below
3) which charger you use (fast (E6000) or slow (E6002) charger) Fast
4) Battery BT-E8010 504wh
5) 1065 miles
6) Original battery is 10 months old/ 2nd battery is 3 months old
7) Always stored inside the house

Confused by my data. My original battery, the one that shows 98% health and has the most cycles is the battery that dies when its on 2 bars and I would say I get less distance out of.

 

[nosenada]

It seems that there is something wrong with BT-E8035 batteries. So far I've had 2 of these batteries and both have dropped capacity exactly the same way: 100%>90% at 10 cycles and 90%>87% at 20 cycles. Currently I'm at 24 cycles so let's see what happens at 30 cycles...

I had the same degradation at about 10 cycles (100% > 90%) and 20 cycles (90% > 87%) on my two e8035 batteries.

At about 30 cycles both batteries dropped 87% > 85%.

At around 36 cycles my older battery went up to 85% > 87% then dropped from 87% > 84% at 38 cycles. It then dropped further 84% > 82% at 40 cycles. The eco reserve time on that battery is now basically non existent and it goes basically straight to off.

My newer battery dropped from 87% > 85% health at around 33 cycles.

Range is an issue now and the lack of the eco reserve time sucks.

I just received a call from my local shop that my replacement warranty batteries from Shimano just came in. My replacement batteries took almost two months to come in from the time Shimano agreed to replace them.

 

[Stuart569]

I had the same degradation at about 10 cycles (100% > 90%) and 20 cycles (90% > 87%) on my two e8035 batteries.

At about 30 cycles both batteries dropped 87% > 85%.

At around 36 cycles my older battery went up to 85% > 87% then dropped from 87% > 84% at 38 cycles. It then dropped further 84% > 82% at 40 cycles. The eco reserve time on that battery is now basically non existent and it goes basically straight to off.

My newer battery dropped from 87% > 85% health at around 33 cycles.

Range is an issue now and the lack of the eco reserve time sucks.

I just received a call from my local shop that my replacement warranty batteries from Shimano just came in. My replacement batteries took almost two months to come in from the time Shimano agreed to replace them.

So you got Shimano to replace both batteries? How did you go about this?

 

[nosenada]

So you got Shimano to replace both batteries? How did you go about this?

Yes, Shimano replaced both batteries although I am yet to pick them up as I just received the call that the batteries had come in.

I asked my LBS to warranty them. One of the batteries I purchased from the LBS as a special order and one of the batteries came with the bike which was a Commencal.

The LBS was not super familiar with ebikes or batteries so it took a little time to explain and patiently answer questions that may not be relevant.

The service ticket writer called up Shimano then sent me on my way as Shimano wanted to see more degradation. The batteries were at 90% (10 cycles and 2 months old) and 87% (23 cycles and 5 months old) at that time.

About a month later they dropped to 87% (20 cycles ) and 85% (33 cycles), I took them back in to the LBS and Shimano agreed to warranty them.

Overall I am happy with the outcome even though it took almost 3 months from the time I brought the issue up, to the time the batteries arrived. LBS was great to deal with and took the time to learn about the issue.

 

[Stuart569]

Yes, Shimano replaced both batteries although I am yet to pick them up as I just received the call that the batteries had come in.

I asked my LBS to warranty them. One of the batteries I purchased from the LBS as a special order and one of the batteries came with the bike which was a Commencal.

The LBS was not super familiar with ebikes or batteries so it took a little time to explain and patiently answer questions that may not be relevant.

The service ticket writer called up Shimano then sent me on my way as Shimano wanted to see more degradation. The batteries were at 90% (10 cycles and 2 months old) and 87% (23 cycles and 5 months old) at that time.

About a month later they dropped to 87% (20 cycles ) and 85% (33 cycles), I took them back in to the LBS and Shimano agreed to warranty them.

Overall I am happy with the outcome even though it took almost 3 months from the time I brought the issue up, to the time the batteries arrived. LBS was great to deal with and took the time to learn about the issue.

Brilliant thanks for the detailed response. How did they check the battery health? Laptop and DI2 interface? Do they get any more data from the battery like individual cell readouts or readouts from a set of cells similar to DIY type battery management systems? It's likely that one or more vattery cells are going faulty which is causing these issues. It would be nice to know if the laptop gave more info for post warranty repairs.

 

[nosenada]

Brilliant thanks for the detailed response. How did they check the battery health? Laptop and DI2 interface? Do they get any more data from the battery like individual cell readouts or readouts from a set of cells similar to DIY type battery management systems? It's likely that one or more vattery cells are going faulty which is causing these issues. It would be nice to know if the laptop gave more info for post warranty repairs.

I checked the battery health with my pce02 interface which is one of the official diagnostics device Shimano sells to bike shops. I brought copies of the report it generates for both batteries to the LBS.

The pce02 interface using Shimano's eTube software only provides the overall battery health which is named in the report "Battery remaining capacity". No per cell readouts are provided.

 

[Sherman]

Don't think that derestriction has that big of an effect. Steep uphills with poor traction are what strains on the battery the most and there it's difficult to reach more than 25 km/h

Speed and increased air resistance is a major factor in power consumption. 25->32km/h requires ~100W more power.

 

[Stuart569]

I checked the battery health with my pce02 interface which is one of the official diagnostics device Shimano sells to bike shops. I brought copies of the report it generates for both batteries to the LBS.

The pce02 interface using Shimano's eTube software only provides the overall battery health which is named in the report "Battery remaining capacity". No per cell readouts are provided.

Agh okay fair enough. So basically they're not keen on warranty replacements until around the 85% mark. Does anyone know how long a warranty we get on the batteries?

 

[nosenada]

Agh okay fair enough. So basically they're not keen on warranty replacements until around the 85% mark.

Maybe it is hard to say. My guess it is a mix of cycle count, age, and battery health. Also, the country you are in. I am in the United States.

My batteries had degraded a significant amount after a very low amount of cycles and being only a few months old.

If your battery is at 85% health at month 23 of the 24 month warranty and at 250 cycles you may get a different response.

Official warranty is 2 years or 1000 cycles at 60% health. While I would expect 60% health maybe at 1000 cycles I sure hope my battery is way above 60% health after 2 years.

 

[Stuart569]

Maybe it is hard to say. My guess it is a mix of cycle count, age, and battery health. Also, the country you are in. I am in the United States.

My batteries had degraded a significant amount after a very low amount of cycles and being only a few months old.

If your battery is at 85% health at month 23 of the 24 month warranty and at 250 cycles you may get a different response.

Official warranty is 2 years or 1000 cycles at 60% health. While I would expect 60% health maybe at 1000 cycles I sure hope my battery is way above 60% health after 2 years.

I just found the 60% at 1000 cycles bit on the Shimano website. Assuming linear degradation that would be 0.04% per charge cycle.

 

[RickBullotta]

FWIW, they refused to warranty my battery at 93% after 40-some cycles...

 

[Stuart569]

FWIW, they refused to warranty my battery at 93% after 40-some cycles...

I guess you should try again nearer the 85% mark then... It worked for @nosenada. I'll be doing the same

 

[nosenada]

I guess you should try again nearer the 85% mark then... It worked for @nosenada. I'll be doing the same

Note also that part of my warranty claim involved a e6002 (slow charger) that I believe, and argued, was damaging the battery as it would not slow down its charging rate when the SoC was above 80%. The charge rate of my e6002 charger above 80% was faster than the e6000 (fast charger).

That said best of luck on your warranty claim.

 

[aajiikoo]

I received a warranty replacement battery from Shimano after my battery was at 87% after 20 cycles and less than 2 months of use. But as I said earlier this new battery has dropped capacity exactly the same way.

 

[Stuart569]

I received a warranty replacement battery from Shimano after my battery was at 87% after 20 cycles and less than 2 months of use. But as I said earlier this new battery has dropped capacity exactly the same way.

That's pants. I wonder how the health calculation works though as I said before my battery showing as healthier seems to last longer than the one showing almost 100% health.

 

[OldGoatMTB]

I'm at 6 cycles and still 100%.

 

[nosenada]

I received a warranty replacement battery from Shimano after my battery was at 87% after 20 cycles and less than 2 months of use. But as I said earlier this new battery has dropped capacity exactly the same way.

That is terrible that your new battery is also declining in health.

How long ago did you receive the replacement? Do you use boost mode a lot?

I wonder if the new batteries I just picked up are of new stock with the issue corrected or if I am going to have the same problem.

I have a new theory that the e8035 batteries may be declining in health rapidly because they are not able to dissipate heat as well as the e8010 which are externally mounted allowing airflow around the battery.

Even though my e8035 battery sits in my aluminium frame there is at least 5mm of dead air surrounding it between the battery and the frame. On the bottom there is a rubber protector that likely also prevents heat from escaping.

Last night I measured the temperature of my brand new battery 30 min after my ride ended and it was still at 85deg F. The outside temp at the time was 68deg F. That was a ride that was mostly in trail mode.

 

[RickBullotta]

That is terrible that your new battery is also declining in health.

How long ago did you receive the replacement? Do you use boost mode a lot?

I wonder if the new batteries I just picked up are of new stock with the issue corrected or if I am going to have the same problem.

I have a new theory that the e8035 batteries may be declining in health rapidly because they are not able to dissipate heat as well as the e8010 which are externally mounted allowing airflow around the battery.

Even though my e8035 battery sits in my aluminium frame there is at least 5mm of dead air surrounding it between the battery and the frame. On the bottom there is a rubber protector that likely also prevents heat from escaping.

Last night I measured the temperature of my brand new battery 30 min after my ride ended and it was still at 85deg F. The outside temp at the time was 68deg F. That was a ride that was mostly in trail mode.

My E8010 batteries are declining fast also. And I don't think the issue has been "corrected" - I think Shimano is just trying to put off warranty claims as long as they can and then providing a new, but same, battery. There was a charger change, which may be an attempt at a "fix". I wish Shimano would be transparent about this. The support person I spoke with seemed to feel bad that he had to tell me they wouldn't warranty it, like he'd heard my story more than a few times...

 

[nosenada]

My E8010 batteries are declining fast also.

Do you use boost mode a lot for long sustained climbs?

My other theory is lots of boost mode is really hard on the battery, which sucks because its a great way to get in fast laps.

 

[RickBullotta]

Do you use boost mode a lot for long sustained climbs?

My other theory is lots of boost mode is really hard on the battery, which sucks because its a great way to get in fast laps.

Almost never. 60% Eco, 40% Trail, less than 1% Boost would be my estimate. I've set mine up so that Trail peaks at the same assistance/power as Boost, but is modulated better. Even for races, I've found Trail is preferable as the bike handles better.

 

[electricbogaloo]

Do you use boost mode a lot for long sustained climbs?

My other theory is lots of boost mode is really hard on the battery, which sucks because its a great way to get in fast laps.

Boost means your emptying the battery faster and the number one thing that makes a battery age is when it sits around completely empty. If you do Boost-runs ideally you wouldn't drain them to the last drop every ride especially if you have two batteries and don't need their capacity at once. I would even it out and use up battery 1 until 2 blocks are still showing and then use the next one until two blocks. Ofc there won't happen much if you empty your battery once or twice in a while but if you empty them on every ride and then let them sit around for a few hours or overnight emptied that could lead to them aging faster.

 

[Stuart569]

8mm

Boost means your emptying the battery faster and the number one thing that makes a battery age is when it sits around completely empty. If you do Boost-runs ideally you wouldn't drain them to the last drop every ride especially if you have two batteries and don't need their capacity at once. I would even it out and use up battery 1 until 2 blocks are still showing and then use the next one until two blocks. Ofc there won't happen much if you empty your battery once or twice in a while but if you empty them on every ride and then let them sit around for a few hours or overnight emptied that could lead to them aging faster.

Is it though? The batteries have a cut off point. Why would that point be at a level that is detrimental to the health of the battery? Yes leaving a battery either empty of full for extended periods is bad practice but I don't belive that using it until it cuts off is...

 

[electricbogaloo]

Because of weight and cost. Sure you could put enough cells in there for 700Wh and let users only use 400 of them but what's the point? It would cost the manufacturer more money, add weight only for longer battery life? Shimanos bms could be more conservative but it could also mean that the shimano cells aren't as good as the bosch cells or the motor is not efficient as the old CX (which is probably true due to the gearbox sheme).

 

[Marc_250]

I've seen the E8010 battery as cheap as £399 (although now out of stock there) so at a point where simply routinely replacing them annually etc is possible.

That said I'm hoping as others that the aftermarket delivers some better options but not seen anything yet. Would gladly pay more than retail for a better quality/more capable replacement/refurb.

 

[Ozone08]

I have no idea how but iv done 1200 plus km in 5 months on my decoy and my battery reads 99% (0 cycles)

Im using the default TY charger (slow) and generally charge when i get down to 2 bars.

 

[OldGoatMTB]

I have no idea how but iv done 1200 plus km in 5 months on my decoy and my battery reads 99% (0 cycles)

Im using the default TY charger (slow) and generally charge when i get down to 2 bars.

View attachment 30282

That just seems wrong, at the number of cycles is basicly a measure of how much energy has been transferred into the battery divided by the capacity of the battery. In other words, if charged from 0 to 100 ten times that's 10 cycles. charged form 50 to 100 four times is 2 cycles. It shouldn't say 0 cycles unless it hadn't been charged.

 

[aajiikoo]

That is terrible that your new battery is also declining in health.

How long ago did you receive the replacement? Do you use boost mode a lot?

I wonder if the new batteries I just picked up are of new stock with the issue corrected or if I am going to have the same problem.

I have a new theory that the e8035 batteries may be declining in health rapidly because they are not able to dissipate heat as well as the e8010 which are externally mounted allowing airflow around the battery.

Even though my e8035 battery sits in my aluminium frame there is at least 5mm of dead air surrounding it between the battery and the frame. On the bottom there is a rubber protector that likely also prevents heat from escaping.

Last night I measured the temperature of my brand new battery 30 min after my ride ended and it was still at 85deg F. The outside temp at the time was 68deg F. That was a ride that was mostly in trail mode.

I received the replacement battery last February. I don't think that the heat dissipation is the problem because so far I've been riding my bike mostly in temperatures below 0C and the battery is cold after riding. I let it warm up to room temperature before I charge it. I have used boost mode very rarely, 90% of my riding is in trail mode and the rest in Eco mode.

It would be interesting to know how the battery health calculation works because the battery capacity degradation seems a bit odd:
- exactly at 10 cycles: 100>90%
- exactly at 20 cycles: 90>87%
- exactly at 30 cycles: 87>85%
Because of this pattern I'm wondering if the degradation is really happening or is this some kind of a software bug. A month ago I bought an extra battery but I haven't yet taken it into use but when I do, I'll test if the range is better with the fresh battery.

 

[R120]

I actually dont trust the shimano softwares evaluation of the battery health - I have had one E8010 for 2 years now, and aside from in the winter when the range drops, I can pretty much get the same distance out of it for my local riding - it must have had well over 250 charges during that time, a I ride my bikes every other day (but have two batteries). My other battery is about 20 months old, and same situation.

I will check on the app to see what it says, but I cant say I have noticed any significant drop of in range, other than when the bike was derestricted which I found cut the range by quite a bit, due to the motor always drawing power.

My regular quick blast is 12 miles and 1500ft of elevation, and pretty much every ride by the time I get home, having ridden fully in trail, it just tips into 4 bars, and always has done.

 

[R120]

So my 2 year old battery says 95% health and 45 cycles.

 

[nosenada]

I received the replacement battery last February. I don't think that the heat dissipation is the problem because so far I've been riding my bike mostly in temperatures below 0C and the battery is cold after riding. I let it warm up to room temperature before I charge it. I have used boost mode very rarely, 90% of my riding is in trail mode and the rest in Eco mode.

It would be interesting to know how the battery health calculation works because the battery capacity degradation seems a bit odd:
- exactly at 10 cycles: 100>90%
- exactly at 20 cycles: 90>87%
- exactly at 30 cycles: 87>85%
Because of this pattern I'm wondering if the degradation is really happening or is this some kind of a software bug. A month ago I bought an extra battery but I haven't yet taken it into use but when I do, I'll test if the range is better with the fresh battery.

I do not think it is a software bug as both of my original batteries had a notable reduction in range. It was especially noticeable once it fell to 85% and the forced eco reserve at the end was almost non-existent.

I now have my two new warranty replacement batteries and I am hoping they do not degrade as fast. One of the batteries is at 5 cycles and is still at 100% health. Will see once it hits 10.