Shimano Battery Life Poll

OldGoatMTB

E*POWAH Master
Mar 24, 2020
423
253
27284
My battery says n100% after 9 cycles. Wondering if it's like the gas gauge that stays on full for 80 miles and then drops to 3/4 tank. Or like the iPhone battery meter.
 

nosenada

Member
Nov 26, 2019
50
29
California
Update on my two warranty replacement e8035 batteries I picked up less than a month ago.

Battery 1 - 7 cycles and 100% health.

Battery 2 - 4 cycles and 91% health. (I have only had it for 20 days!)

Both always stored inside between 40% and 70% charge, only charged immediately before my rides, and only charged with the e6000 fast charger.

I noticed on probably my second ride on Battery 2 that it seemed to have slightly less range than Battery 1, but did not check the battery health then.

Looks like I will make another warranty claim on Battery 2.
 

nosenada

Member
Nov 26, 2019
50
29
California
Now the other warranty replacement battery e8035 shows 11 cycles and 90% health. (I just received it a little over a month ago.) The other battery is still at 91% health at 7 cycles.

My wife's battery has a e8010 battery and it still shows 100% health at 9 cycles. It is almost 5 months old.

I think something is wrong with Shimano's e8035 batteries.
 
Last edited:

aajiikoo

Member
Jan 29, 2020
14
14
Finland
And now my E8035 battery is at 41 charge cycles:
- 10 cycles: 100>90%
- 20 cycles: 90>87%
- 30 cycles: 87>85%
- 40 cycles: 85>82%

But I still have a decent range of ~35km (mostly in trail mode, 100% assist setting) so at the moment I'm not sure if this degradation is for real. I guess I'll find out that soon as I'm going to start using the other fresh battery because there is the first enduro race of the season next week.
 

aajiikoo

Member
Jan 29, 2020
14
14
Finland
Ok, so yesterday I had a ride with the new battery and to me it looks more and more like this battery degradation is a software issue. The range I got from this new battery was very similar to what I get from the old 82% battery: ~1000m of climbing and ~35km on 100% assist setting.
 

RocketMagnet

Well-known member
Dec 16, 2018
166
134
UK
I've had my E8010 for about 15 months. I ran the battery to exhaustion soon after I got the bike on a specific series of loops, I ran the same a couple of days ago and got very similar result just staying in Eco 95% (it was warmer than my first test though). So personally I'm not seeing any significant real world drop off in capacity but it must be occurring, presumably it wont be linear with the rate of loss slowing. I've not done lots of cycles though (30-50 cycles possibly) as I don't ride my E-bike exclusively and ride my normal bike more.

A major impactor is rate of discharge... I rarely if ever use Boost and mainly stay in Eco and some trail so perhaps it's helping a bit?
I also reduced the assist level for Boost and Trail. I always store the bike indoors and fully charge the next day not right after i get in from a cold ride. I've had periods where I didn't ride the Ebike and I didn't store the battery correctly.. I left it fully charged so i'm actually surprised i'm not seeing much apparent degradation... possibly it was ambient dragging down my initial test.

Not all battery's are equal however and there could be some failed cells causing rapid capacity loss people are seeing?... The battery software will be managing this. Also as far as I can tell determining an actual "Capacity" isn't that accurate. IME you just get a feel for how much your asking of the assist.. and use the battery indicators as a rough guide.

If you derestrict then there is the increased potential to damage and reduce the battery capacity so in this instance it's kind of your own fault and you just have to accept reduced battery life.

Something I've always done is if a Li Ion battery ever switches off due to low charge I never try and power it back up as you can eat into the safety reserve power used by the battery to maintain itself. I doubt it that much of an issue on a 504MWh battery though :)
 

RickBullotta

E*POWAH Elite World Champion
Jun 5, 2019
1,743
1,488
USA
I'd love to know if there are any battery experts watching this thread who can suggest a more accurate way to verify true battery capacity and compare it to the values returned by the Shimano software/firmware so that we can try to assess what is real.
 

ceejays88

New Member
May 28, 2020
18
4
Wirral
this is slightly different to what you are asking but someone might be able to shed some light on this....

I have 2 (Different) bikes with the same 8010 battery in them so I ran a test on both batteries on 1 bike. (I only use 1 charger as the 2nd charger came with an EU plug)
test bike: Vitus e-sommet (standard model) e7000
Battery 1-
4 cycles
100% charge and health
51km in eco on my standard route (very little climbing about 200m), no wind but it was quite warm
Battery 2-
5 cycles
100% charge and health
72km in eco on my standard route in the pretty much the same conditions, warm and no/little wind

I knew something was "different" after the first 10km when I would usually see a dropped bar on the battery to indicate 80% but the other battery took until 15km to drop.

Got them both on the table and plugged one in, lights came on to show its charging... great.
Next day I plugged in the 2nd battery and I noticed that the lights on thi battery were much brighter than the other one!

Am I looking at a faulty battery ?‍♂️
 

KeithR

Well-known member
Jul 1, 2020
679
610
Blyth, Northumberland
Now the other warranty replacement battery e8035 shows 11 cycles and 90% health. (I just received it a little over a month ago.) The other battery is still at 91% health at 7 cycles.

My wife's battery has a e8010 battery and it still shows 100% health at 9 cycles. It is almost 5 months old.

I think something is wrong with Shimano's e8035 batteries.
Probably a silly question - but have you tried a battery reset?
 

nosenada

Member
Nov 26, 2019
50
29
California
Probably a silly question - but have you tried a battery reset?

I do not know of a way to do a reset with a Shimano battery.

I have, every once and a while drained them completely, and recharged to 100% which generally resets the BMS remaining charge percent calculation on most lithium batteries.
 

Apr 18, 2020
117
32
germany
1) # of charging cycles 17
2) remaining capacity 100%
3) I use E6000 charger exclusively
4) Battery BT-E8010 504wh
6) 12 months old / ~ 900 miles

I store the battery between 15-20 degrees celcius in a dark chamber and try to only charge it to 100% when I need it and then only right before I leave for the ride. I also try to avoid to fully empty it if it's not needed and if it happens I charge it up as fast as possible.

When I store it longterm then at 30-40%. I ride almost exclusively in Eco/High mode with 90-100 rpm and Im fairly light (around 70kg with gear). Boost-mode feels to strong anyway with that weight.

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
 

jimbob

Active member
Aug 3, 2020
517
427
East UK
An interesting topic. I'm an engineer, so like geeky stuff like this. I plan to keep a record as I go for interest.

Not many cycles on mine yet, but for what its worth;

1) # of charging cycles 5
2) remaining capacity 100%
3) E6002 charger
4) Battery BT-E8035 504wh

It would be interesting to setup a simple discharge rig to measure the actual capacity. And not that difficult given the output seems to be a direct connection to the battery itself. I may have a quick look to see how much a cheap voltage datalogger is.
 
Apr 18, 2020
117
32
germany
Someone did that in this thread:


But I can't find it on mobile right now

Edit:

They talk about 460 to 510 Wh when the battery was completely empty. But you have to calculate the losses from the charger.
 
Last edited:

jimbob

Active member
Aug 3, 2020
517
427
East UK
Cant do a translation on my phone unfortunatly, but guessing they measured the power in tothe charger? Thats not a bad idea to give a rough comparison of battery health over time actualy. It wont give an accurate idea of actual capacity, but for degradation it would work. especialy when people are seeing >10% degradation reported.
 
Apr 18, 2020
117
32
germany
DiagrammUnbenannt.PNG


So here is what a few guys over there measured. They divided it through 1:17 to simulate the efficiency of the charger. This is not pinpoint accuracy but it gives some hints that not alle manufacturers operate with the same strategy. The batteries are either new, which means the measurement took place on the third charging cycle to get full capacity, or one year old or the charging cycle amount is mentioned. One source of error could be that the people treat their batteries differently. But the amount of batteries show at least some tendencies.

source:

 
Last edited:

Stanczech

Active member
Subscriber
I have had MERIDA eONE-SIXTY 900-E size XL since March 2019, my beloved wife has had eONE-SIXTY M#RIDA METALLIC CRIMSON (RED LIGHTNING) size M since July 2019.
We use only the Shimano EC-E6000 charger,
battery 2x Shimano BT-E8010, Li-ion 36V-14 Ah-504 Wh.
Sometimes I use a battery from M#rida, which my wife rides on. So my battery has less km than my Merida, and vice versa.

Merida battery:
now 8.045 km / 5,012 miles approx
battery health 91%
charging cycles 66.

M#erida battery:
now 5.906km / 3,679 miles approx
battery health 97%
charging cycles 42.

So far, so good(?) We'll see how it goes.

Photo when we just imported M#rida from the seller.
IMG_20190724_193314_upr.jpg
 
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thebarber

E*POWAH Elite
May 28, 2018
986
596
Norfeast
Here's a start.
brand fire new battery, surprised it was tit flat but hey ho
3hr30min later full.
I'll keep an eye on it.
20200820_155757.jpg
 

E-Bandit

Member
Sep 1, 2020
30
6
Australia
Hi Everyone,

I have two batteries, one i use for commuting to work and the other is used for weekends and trail riding,
the battery i commute on i only charge to 80Percent and use to 40percent then charge t again at work to 80 percent for the trip home, always kept inside house or office,

The shimano app on the iPad called E-Tube for tablet shows my battery at the following:
Battery BT-E8035
Charger EC-E6000(both at home and work)
Cycle Count : 73
Remaining Capacity : 78%

has done 3500 KM

should i be speaking to shimano or waiting for it do drop below 70 Percent as per there chart taking in cold wheather commuting in the morning can be around 1-2 degrees C.
 

jimbob

Active member
Aug 3, 2020
517
427
East UK
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... On my previous bike I had 2 BT-E8010 batteries and one was at 92% after 80 cycles and the other at 100% after 20 cycles. I've handled all of these batteries exactly the same way: usually I ride until the bike shuts down and then use the fast charger to charge it to 100% after the battery has cooled/warmed to room temperature. I don't store it at 100% for a long time because usually I ride almost every day.

Ive just hit 10cycles on an E8035, and dropped down to 90%. I would put money on this being a software issue rather than actual cell degradation given both the rapid nature which it has happened and that lots of others seem to have seen the same pattern.

I also dont seem to have seen any decrease in range, which supports the theory. Wait until 20cycles I guess!
 

Nickolp1974

Active member
Jul 30, 2019
235
174
Louth lincs
Out of interest, does the place of manufacturer make a difference?? I have 2 8010's one on mine at 86% 66 cycles made in Japan and packaged in China and the Mrs is a new bike so only 3 cycles 100% made in Singapore and packaged in China.
 

Milan

Member
Sep 9, 2020
91
34
Czech Republic
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.
 

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