Shimano Battery Life Poll

jimbob

Active member
Aug 3, 2020
520
432
East UK
I thought that the warranty was for 80% at 500 cycles or 60% at 1000, so would expect them to honour your claim based on the above?

Out of interest, have you actualy noticed a drop in capacity?
 

aajiikoo

Member
Jan 29, 2020
14
14
Finland
I thought that the warranty was for 80% at 500 cycles or 60% at 1000, so would expect them to honour your claim based on the above?
If that's the case then I guess I'll have to make a warranty claim now after the racing season is over. Last time I checked my older battery had the capacity of 78% after 70+ cycles and the newer battery had 88% after 20+ cycles. The range have been getting noticeable lower when riding with the older battery.
 

Milan

Member
Sep 9, 2020
91
34
Czech Republic
I thought that the warranty was for 80% at 500 cycles or 60% at 1000, so would expect them to honour your claim based on the above?

Out of interest, have you actualy noticed a drop in capacity?
I go biking with a friend of mine and he rides a Ghost with 375 wh (8000, health 99%), when we finish our rides ups and downs of 30 kms or so I do not have any spare miles to go. This 20% loss is apparent. I checked back with some other dealers and both said my battery must be faulty and do not understand why Shimano is arguing with me.
 

jimbob

Active member
Aug 3, 2020
520
432
East UK
I go biking with a friend of mine and he rides a Ghost with 375 wh (8000, health 99%), when we finish our rides ups and downs of 30 kms or so I do not have any spare miles to go. This 20% loss is apparent. I checked back with some other dealers and both said my battery must be faulty and do not understand why Shimano is arguing with me.
Based on this thread, I would guess they are keen to not have a significant number of batteries needing replacement. Whether it's a software or real issue, the result for them is the same, and batteries are not a cheap thing to replace.
 

Milan

Member
Sep 9, 2020
91
34
Czech Republic
Based on this thread, I would guess they are keen to not have a significant number of batteries needing replacement. Whether it's a software or real issue, the result for them is the same, and batteries are not a cheap thing to replace.
You may have a laugh, guess what Shimano said to me: go biking another 2000 km and if you loose another 20% we will replace it! :))) Perfect customer treatment in white gloves :) I won't let it go like this.
 

jimbob

Active member
Aug 3, 2020
520
432
East UK
You may have a laugh, guess what Shimano said to me: go biking another 2000 km and if you loose another 20% we will replace it! :))) Perfect customer treatment in white gloves :) I won't let it go like this.
Not the best customer service!

Ive just tried to find the official line on the warranty, and I'm sure they have changed it. On the UK FAQs, it only mentions 1000cycles, and on the US equivelant nothing abiut cycles, only that is will degrade ~5% per year.



You could try taking it back to where you purchased it from and saying it's not fit for purpose?
 

Milan

Member
Sep 9, 2020
91
34
Czech Republic
Not the best customer service!

Ive just tried to find the official line on the warranty, and I'm sure they have changed it. On the UK FAQs, it only mentions 1000cycles, and on the US equivelant nothing abiut cycles, only that is will degrade ~5% per year.



You could try taking it back to where you purchased it from and saying it's not fit for purpose?
This is what I did, Merida, Czech Republic and they only contacted Shimano, Czech Republic, no diagnostics, your battery is fine. I am taking my bike today to another dealer who will run Shimano diagnostics. They can also run a performance test. Will see what comes up tomorrow, will keep you posted.
 

E-Bandit

Member
Sep 1, 2020
30
6
Australia
I also contacted shimano and only got a response to fully discharge the battery and recharge and check the status, I done this with the same result as before, I have contacted them again and wait and see, I don’t think I have really seen a drop in performance other than the health status showing 78 percent ,
 

urastus

⚡The Whippet⚡
May 4, 2020
1,548
995
Tasmania
Hi all,
just filed a warranty claim with Shimano.

1) # of charging cycles 46
2) remaining capacity 81%
3) E6002 charger
4) Battery BT-E8035 504wh
5) 2190 km

Basically, I currently loose 1% of battery capacity on every 100 km. A Shimano tech said it was ok and closed the claim. I will reopen this claim next week as all my friends run the same shimano 7000 or 8000 and their battery health is 97 to 99% with more or less the same mileage. After reading all comments here and contacting all sorts of dealers, I am more than certain that there is something fishy about BT-E8035 504 wh!!! It is simple: some pieces are fine, some are not. Whatever the charger or conditions. I wish I was the lucky one to win the right piece if I ever get to win this battle! My customer expectation is that I should be now having a battery with the health of 98% to min. 93%. This would also be in line with what Shimano claims and advertizes.
Hi Milan. How have you done 2200km on only 46 charging cycles? And, do you ever fully charge the battery?
 

urastus

⚡The Whippet⚡
May 4, 2020
1,548
995
Tasmania
I have a doozy - for a while now I've been charging to roughly 60%. I keep a record but I only go by the battery bars left on the display, the rest is a guesstimate. Eg, if I have one bar left I try to accurately guesstimate what percentage that is, 10 or 15 etc. always rounded to 5%. I'm always in the ballpark with my charging etc. My system is if I guesstimate that I have 15% (one bar showing) I need to add another 45% to get to 60%. I've figured out that 1% pretty much correlates to 255 seconds - that seems to work for up to 80%. I have the slow charger. Anyway I did my one monthly full charge to balance out cells, did a ride and had 3 bars showing. I had done a fair bit of riding with those 3 bars showing so guesstimated that I had 45% and needed 15% charge to top it up to 60%. So I set the charger for 1hr 4mins (15 x 255 seconds). It showed as fully charged! It's the only time that the system has done something totally random like that. I checked my timer and the times were correct. Even if it was bang on 60% it should not be showing fully charged (60% + 15% = 75% = 4 bars still). Any ideas?
 
Last edited:

Milan

Member
Sep 9, 2020
91
34
Czech Republic
Hi Milan. How have you done 2200km on only 46 charging cycles? And, do you ever fully charge the battery?
The previous owner charged it as he pleased (as told by Shimano), i.e. charge it anytime you can, since you need to ride soon again (34 cycles). The remaining 12 cycles are mine which mounts to around 650 km. Those were charged from the last bar to five full + LED light on the charger off (as I was told again that's the only time when it is fully complete and finished). Two cycles of those 12 were a complete discharge and a complete charge as I was told this would remedy the battery health....as somebody already noted in this thread. On Saturday we are going to test same 504 shimano batteries. His saying healthy, mine saying unhealthy :) Let's see how far we can get and whether this is just a software bug....
 

E-Bandit

Member
Sep 1, 2020
30
6
Australia
The previous owner charged it as he pleased (as told by Shimano), i.e. charge it anytime you can, since you need to ride soon again (34 cycles). The remaining 12 cycles are mine which mounts to around 650 km. Those were charged from the last bar to five full + LED light on the charger off (as I was told again that's the only time when it is fully complete and finished). Two cycles of those 12 were a complete discharge and a complete charge as I was told this would remedy the battery health....as somebody already noted in this thread. On Saturday we are going to test same 504 shimano batteries. His saying healthy, mine saying unhealthy :) Let's see how far we can get and whether this is just a software bug....

Interested to see the outcome of this test :)
 

urastus

⚡The Whippet⚡
May 4, 2020
1,548
995
Tasmania
The previous owner charged it as he pleased (as told by Shimano), i.e. charge it anytime you can, since you need to ride soon again (34 cycles). The remaining 12 cycles are mine which mounts to around 650 km. Those were charged from the last bar to five full + LED light on the charger off (as I was told again that's the only time when it is fully complete and finished). Two cycles of those 12 were a complete discharge and a complete charge as I was told this would remedy the battery health....as somebody already noted in this thread. On Saturday we are going to test same 504 shimano batteries. His saying healthy, mine saying unhealthy :) Let's see how far we can get and whether this is just a software bug....
Yes, that makes sense. I should have done some quick math - 46 charges for 2200km sounds phenomenal, but it isn't. It sounds as though you have a routine for charging, supposedly our batteries are happiest between 30 and 60%. This is just something to consider. I charge as needed. Most of the time for me, a 20km steep ride on eco leaves me close to that first bar transition (20%) from 60%. The occasional ride I do with a friend in trail mode I charge more; and a full balance charge once a month or so. I charge back up to 60% after a ride. The beauty of this is, if I don't get another ride in for a few days, the battery is sitting at a comfortable charge for storage.
 

jimbob

Active member
Aug 3, 2020
520
432
East UK
I think the way it counts a charge cycle is for a full discharge, so if you have two rides which use 50% each, and charge in between, thats still only counted as a single cycle.
 

Milan

Member
Sep 9, 2020
91
34
Czech Republic
Just finished the comparison of the two 504 wh Shimano batteries, one being external, mine internal BT-E8035. As I reached the end of the readings, I learnt that the silly Biker #2 had changed the parameters of assistance but forgot to also save them! Nonetheless, it is now very clear that the drop in capacity is not a software bug. We went biking side by side and employed simultaneously all modes available including OFF too. While Bob (Biker #2) was at the end left with two bars and 33% Battery State (had stronger motor and was a little more consuming power with assistance), I had 1% and could go only for another 3 kms or so in ECO blinking mode (with a weaker motor and less favourable assistance). It is clear that I am some 30 kgs heavier and it could create an estimated difference of 15 km in the range. It is a pity we did not have the same model of battery to make it even more accurate. But such are our bikes.

The conclusion is: I consider my battery faulty and will have to send it to be diagnosed after the season is over. If your warranty is close to the end, hurry to file your claim. Let me know what you think. Thanks.

readings.jpg


trip.jpg


milan-stunlocker.jpg


bob-stunlocker.PNG
 
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jimbob

Active member
Aug 3, 2020
520
432
East UK
Unfortunately there are so many variables there it makes it difficult to confirm either way I'd suggest.

I do find it hard to understand how shimano have managed to make batteries which are dropping capacity quite so much if it is real.
 

daddyo

Member
Sep 15, 2019
49
21
Brno, Czech Republic
I am the Silly Biker Nr.2 who rode with Milan. I think the test was a good comparison of batteries. The assistence level on my Ghost was set exactly to the same values as his. The screenprint was done before setting assistence levels to show battery health. We rode together, using exactly the same modes. When his battery died , I still had 32% left. The range in Eco shown was 41 km ( I do know it is a very rough estimate only) Our weight difference is 29 kg but I think I had cca 4 kg worth of weight in the backpack. So all up 25 kg difference. I do think his battery is not that "healthy" considering how young the battery is. I guess he does get cca 15-20 less range than he should.
 

Fabiobi

Member
Sep 17, 2020
2
0
Piacenza
Hello Rick
Herewith my data. Also in Italy, the situation is not very different

1) 42 cycles
2) 84%
3) EC-E6002 Charger for 28 cycles (@94%) than EC-E8004 and capacity drops quickly
4) Battery BT-E8010 - 504Wh
5) 2100 km
6) 16 months
7) Always stored inside the house.
Climbing capacity decrease from 1400 m+ to 1100 m+ I’m 188cm/105 kg.
 

Spiff

Active member
Feb 27, 2019
447
262
Earth
I believe that the bad battery health is related to the battery "version", which is the letter at the end of the battery type.

My battery is two years old and its health is 98% and it has no version letter, I mean, it is BT-E8010. But I know that newer batteries are revisions B and C, ie, BT-E8010C.

I suggest we complement the battery data that we have provided by adding the battery version letter. And may be we can relate the bad battery health to one of the versions, that may have cells from a different supplier that are more prone to fail.
 
Last edited:

Milan

Member
Sep 9, 2020
91
34
Czech Republic
I believe that the bad battery health is related to the battery "version", which is the letter at the end of the battery type.

My battery is two years old and its health is 98% and it has no version letter, I mean, it is BT-E8010. But I know that newer batteries are revisions B and C, ie, BT-E8010C.

I suggest we complement the battery data that we have provided by adding the battery version letter. And may be we can relate the bad battery health to one of the versions, that may have cells from a different supplier that are more prone to fail.
You are definately right, it would be nice to nail that issue down. It may as well be purely related to certain models of batteries. Mine has got no letters either: BT-E8035 and its health is 80% only one year old.
 

jimbob

Active member
Aug 3, 2020
520
432
East UK
You are definately right, it would be nice to nail that issue down. It may as well be purely related to certain models of batteries. Mine has got no letters either: BT-E8035 and its health is 80% only one year old.

May I ask how many charge cycles do you have on it?
 
Apr 18, 2020
182
80
germany
Update

1) # of charging cycles 23
2) remaining capacity 99%
3) I use E6000 charger exclusively
4) Battery BT-E8010 504wh
6) 14 months old / ~1500 km

1) # of charging cycles 31
2) remaining capacity 98%
3) I use E6000 charger exclusively
4) Battery BT-E8010 504wh
6) 17 months old / ~2000 km

note: the second percent degradation happened more rapidly than the first. Due to travelling with a campervan I had to store the battery a few days fully charged (which I normally avoid and only fully charge right before I go riding). Maybe this led to the faster degradation.

BT e-8010 #1
18 months old - 1,342km - 29 cycles
99%
BC e-6000 charger
Always charged to 50% on return from ride, stored in fridge in a sealed bag over summer (so never gets much ambient exposure over 25degC). Only gets charged to 100% immediately before riding (to minimise time in this less than ideal state).

BT e-8010 #2
Brand new (mfg in Singapore Sep 2019) - charged to 100%, once, just out of the box, and then ridden down to 50% charge for storage - so <1 cycle
100% on the Emax app

I learnt from my previous bafang battery that extended high states of charge, particularly over summer with temps >25degC, damage batteries..

How is your battery health now? Would be interesting to see if your batteries degrade slower due to the storing in the fridge and only charging them to 100% before the ride.

I am the Silly Biker Nr.2 who rode with Milan. I think the test was a good comparison of batteries. The assistence level on my Ghost was set exactly to the same values as his. The screenprint was done before setting assistence levels to show battery health. We rode together, using exactly the same modes. When his battery died , I still had 32% left. The range in Eco shown was 41 km ( I do know it is a very rough estimate only) Our weight difference is 29 kg but I think I had cca 4 kg worth of weight in the backpack. So all up 25 kg difference. I do think his battery is not that "healthy" considering how young the battery is. I guess he does get cca 15-20 less range than he should.

More weight means more cycles for the battery which in turn also means that it degrades faster.
 
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nosenada

Member
Nov 26, 2019
50
29
California
My set of warranty batteries (e8035) are declining in health in the same fashion as my original batteries.

Such a low cycle count and rapid degradation in health is not normal and to me indicates a defective design.

I tried to warranty my previously warrantied batteries and now Shimano is saying they need to be at 60% health or lower to qualify for a replacement.

I am disappointed with Shimano's response given this type of rapid decline falls far outside the norm. I expect my batteries to age, but not this fast. I'm hoping that Shimano acknowledges that its e8035 model batteries are defective.

-------------------------------------------------------------------------------------------------------

Original Battery that came with bike:

90% health; 10 cycles

87% heath; 23 cycles (at 87% Shimano agreed to warranty)

85% health; 32 cycles

84% health; 38 cycles

82% health; 40 cycles (exchanged for new warranty battery, took about two months as back ordered)

Original Battery Purchased from LBS:

90% health; 10 cycles

87% health; 20 cycles (either at 90% or 87% Shimano agreed to warranty)

85% health; 30 cycles (exchanged for new warranty battery, took about two months as back ordered)

--------------------------------------------------------------------------------------------------------

Warranty Battery 1

91% health; 4 cycles and - only 20 days old! (Shimano said they wanted more degradation)

89% health; 11 cycles

87% health; 20 cycles (Shimano refused to warranty said it has to be at 60% health)

Warranty Battery 2

90% health; 11 cycles (Shimano said they wanted more degradation)

90% health; 14 cycles

87% health; 21 cycles (Shimano refused to warranty said it has to be at 60% health)
 

steve_sordy

Wedding Crasher
Nov 5, 2018
8,936
9,281
Lincolnshire, UK
When I get in from a ride, I charge the battery for about an hour. This takes the 378Whr battery up to between 70%-80%. The bike is then left until either the night before or the morning of the next ride for a final charge that might take anywhere from 1.5 to 2.5 hours. The time between rides is usually 2-3 days, but may be up to a week, but very seldom more. Irrespective of whether it takes 1.5hrs or 2.5 hrs, whenever I switch off the charger I have received a full charge (only as indicated by declared range), so I guess something else is going on in the last hour (cell balancing?)
 

Milan

Member
Sep 9, 2020
91
34
Czech Republic
My set of warranty batteries (e8035) are declining in health in the same fashion as my original batteries.

Such a low cycle count and rapid degradation in health is not normal and to me indicates a defective design.

I tried to warranty my previously warrantied batteries and now Shimano is saying they need to be at 60% health or lower to qualify for a replacement.

I am disappointed with Shimano's response given this type of rapid decline falls far outside the norm. I expect my batteries to age, but not this fast. I'm hoping that Shimano acknowledges that its e8035 model batteries are defective.

-------------------------------------------------------------------------------------------------------

Original Battery that came with bike:

90% health; 10 cycles

87% heath; 23 cycles (at 87% Shimano agreed to warranty)

85% health; 32 cycles

84% health; 38 cycles

82% health; 40 cycles (exchanged for new warranty battery, took about two months as back ordered)

Original Battery Purchased from LBS:

90% health; 10 cycles

87% health; 20 cycles (either at 90% or 87% Shimano agreed to warranty)

85% health; 30 cycles (exchanged for new warranty battery, took about two months as back ordered)

--------------------------------------------------------------------------------------------------------

Warranty Battery 1

91% health; 4 cycles and - only 20 days old! (Shimano said they wanted more degradation)

89% health; 11 cycles

87% health; 20 cycles (Shimano refused to warranty said it has to be at 60% health)

Warranty Battery 2

90% health; 11 cycles (Shimano said they wanted more degradation)

90% health; 14 cycles

87% health; 21 cycles (Shimano refused to warranty said it has to be at 60% health)
You are definitely right that e8035 are defective and poor design. I have just been told that Shimano will agree to warranty as soon as my battery health is 79%. I, however, doubt that they will do this over and over again. This thread clearly shows that e8035 is a defective design. If you read any study on li-on batteries, they are considered 'dead' as soon as they go down below 80%. I have spoken to a number of retailers and they themselves did with some other ones too, so it now counts 5 who say that there is really something wrong with this model. And admitted that those who shout most are those who get a new one :) I know that this sounds naive but it would be worth going for some collective claim to make this thing clear once and forever with Shimano. Sure, all of that people say here in the thread about how they treat their batteries nice, charge them 80-85% and how healthy they have them, it is all perfect and in line with the best practice, BUT they do not have the e8035.
 

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