Shimano BT-E8035 Integrated Battery Issue: very fast degrading and loss of range
- Thread starter Milan
- Start date
robbydobs
Active member
Found this on the Shimano-TEC site...
Shimano just released 2nd generation internal and external batteries for Steps engines with new BMS BATTERY | SHIMANO BIKE-EU
Is that because of the physical mount or the the electrics?
There are new Battery mounts for internal and integrated batteries, but it is still not known if older motors will be compatible with new battery + Mount
BM-EN600 Mount for external battery
BM-EN800-A and BM-EN800-B Mounts for integrated battery
Last edited:
Shimano did not solve problems with degradation of 1st gen batterries so I hope there will be some compatibility between generations and it will give us more life time on batteries. On my 8010 battery I already had 92% after 13 cycles and just 1200km.
PennywiseTheDancingClown
Member
How do you charge to a particular percentage?
I have an EP8 with 630wh battery.... my charger just plugs in, shows a green light until its fully charged then the light goes out.
It's not charging to to a particular %.
When the battery is new, it should be 100% health.
Status is how much of the battery has been used since being charged.
My battery, for example, was 100% health when new. Meaning my range would show up as 100km on eco.
My battery is now at 92% Health, so when fully charged, it only has 92% of the range it had and only gives me 92km range when fully charged.
I'm basically down 8% on a fully charged battery thats been charged 25 times and covered 900km.
Think of it like your phone battery that dies quickly when it gets old, except the 8035 isn't old and its going flat faster than it should.
When the battery is new, it should be 100% health.
Status is how much of the battery has been used since being charged.
My battery, for example, was 100% health when new. Meaning my range would show up as 100km on eco.
My battery is now at 92% Health, so when fully charged, it only has 92% of the range it had and only gives me 92km range when fully charged.
I'm basically down 8% on a fully charged battery thats been charged 25 times and covered 900km.
Think of it like your phone battery that dies quickly when it gets old, except the 8035 isn't old and its going flat faster than it should.
I believe he he asking how to do a partial charge up to to 60 or 80% and not a Full Charge (Battery degrades quickier).
I am not aware of any method to do this, I do by periodically watching the battery and stopping the charge just when 5th LED starts blinking , which is at 80%
I am not aware of any method to do this, I do by periodically watching the battery and stopping the charge just when 5th LED starts blinking , which is at 80%
PennywiseTheDancingClown
Member
Mine doesnt show anything on the screen when charging... just the steps logo.
I have an external battery and I can see the battery LEDs and monitor the charge, but this thread is for the integrated battery, and in this case, I don't know how to monitor the charge. I am sorry for the confussion.
PennywiseTheDancingClown
Member
How is situation right now?
Can anyone confirm that Shitmano have released a new 504wh battery with different cells and bms.
I’ve had enough of this bullshit battery rode yesterday 32km almost all eco 750 ish elevation and was in the red with 3km range left.
Merida E160 9000 with e8000 motor nearing 5000km, love the bike but the battery is killing me
Battery is at 78% health after 77 charges
I’ve had enough of this bullshit battery rode yesterday 32km almost all eco 750 ish elevation and was in the red with 3km range left.
Merida E160 9000 with e8000 motor nearing 5000km, love the bike but the battery is killing me
Battery is at 78% health after 77 charges
Yes, Shitmano has released new batteries, but they are not compatible with older motors like E8000 or.EP8, only EP801 and EP600.
Thread 'Shimano 2nd Generation Batteries' Shimano 2nd Generation Batteries
Thread 'Shimano 2nd Generation Batteries' Shimano 2nd Generation Batteries
It's your lucky day! Shimano offers great support and still makes the battery you need. I ordered one on February 3 and had it in my hands on February 14.
Christ almighty!
Are you here to solve the problem or just mope about?
Buy the battery, sell the bike, or let it rot in your garage.
Pick one.
Christ almighty alright, I would love to solve the problem but unfortunately above my pay grade. Don’t see why it should be up to consumers to fix a Shimano problem. Especially when its only with 1 model of battery as well. Buying a battery every year shouldn’t even be on the cards
Pivot
E*POWAH Master
Sorry for the delay… interestingly, I have 96% battery health at 28 cycles and 2840km on the clock.
This indicates that my average range is 100km.
However, on full battery stored in a warm place the bike still indicates theoretical range of 170km in Eco mode. Riding in 0-5° C the battery range is definitely well below 100km… we will see in spring and summer.
Sidney Hiro
New Member
A minha e-bike ficou ruim com apenas 10 ciclos.
A autonomia no modo economico caiu para 89km com a carga completa.
E a saúde da bateria estava com 90%.
Falei com a Shimano e eles trocaram a bateria.
Mas nunca deram informações sobre o que aconteceu.
Em um ano já trocaram a bateria para mim 3 vezes.
E a cada 3 meses em média, eu tenho que verificar a saúde da bateria.
Sábado 19/08/2023 levei novamente para a assistência Shimano.
Vamos ver se eles têm alguma solução para esse problema continuo e que pelo jeito está ocorrendo no mundo inteiro.
A autonomia no modo economico caiu para 89km com a carga completa.
E a saúde da bateria estava com 90%.
Falei com a Shimano e eles trocaram a bateria.
Mas nunca deram informações sobre o que aconteceu.
Em um ano já trocaram a bateria para mim 3 vezes.
E a cada 3 meses em média, eu tenho que verificar a saúde da bateria.
Sábado 19/08/2023 levei novamente para a assistência Shimano.
Vamos ver se eles têm alguma solução para esse problema continuo e que pelo jeito está ocorrendo no mundo inteiro.
ebikerlancs
Member
I see E8035 batteries are in the sales currently around the £350 mark. Have they improved at all? Was thinking of getting one to breathe some more life into my Canyon Neuron ON 8 which has degraded to about 70% health.
Will the new battery still do the old trick of going down to 90% health after a few charges?
Will the new battery still do the old trick of going down to 90% health after a few charges?
If anybody like me has stumbled across this thread in 2025+ (it's currently the top Google search result for bt-e8035) and is worrying about their battery, I advise you to read joxelitor's posts on page 5.
That's the only scientific evidence in the thread, the rest is anecdotal and the anecdotal evidence is inconclusive (some say their real-world km decrease matches the battery's reported degradation and some don't).
That's the only scientific evidence in the thread, the rest is anecdotal and the anecdotal evidence is inconclusive (some say their real-world km decrease matches the battery's reported degradation and some don't).
l've read through the thread and more than once have said "forget what the battery is telling you on the app, how much has your ACTUAL RANGE gone down"
But l have generally been ignored.
One of my Shimano batteries is showing "82%" on the app but l still get 30 miles out of it, the same as when it was new.
I bought a second battery and that's currently showing 100% "health" yet l don't get any more range from the bike than my old battery which is showing 82% health.
l wonder if it was always an app or BMS software issue rather than actual battery degradation. Even cheap Ebike batteries last longer than 20 charges before actually degrading, which is when the app said my Shimano battery had lost 10% capacity.
l've got a cheap folding Ebike and the range on that has gone down from 18 miles to around 14 miles.
But l've done 2,700 miles on it. That's a lot of charges at 15 miles per charge.
But l have generally been ignored.
One of my Shimano batteries is showing "82%" on the app but l still get 30 miles out of it, the same as when it was new.
I bought a second battery and that's currently showing 100% "health" yet l don't get any more range from the bike than my old battery which is showing 82% health.
l wonder if it was always an app or BMS software issue rather than actual battery degradation. Even cheap Ebike batteries last longer than 20 charges before actually degrading, which is when the app said my Shimano battery had lost 10% capacity.
l've got a cheap folding Ebike and the range on that has gone down from 18 miles to around 14 miles.
But l've done 2,700 miles on it. That's a lot of charges at 15 miles per charge.
I was losing sleep over some of the claims in this thread so I spent a few hours reading through the entire thread. The drama was entertaining to say the least. There's some good info but a lot of it gets buried under off-topic posts and arguments. Thank you for your posts, they were level-headed and helpful.
The underlying problem is this: The Shimano BT-E8035 and BT-E8010 batteries display faster-than-expected degradation when their diagnostic data is read using the STUnlocker app, and also in Shimano's offical etube app prior to a software update in 2022 that removed that statistic. Many users report the same behavior, a big initial drop in displayed battery health after around 10 cycles, going from 100% to 90%.
There's two competing explanations for this behavior:
A) The battery health is being reported incorrectly in the battery's diagnostic information. This would make it a software display issue rather than a real-world hardware issue. In this scenario, there's no corresponding real-world decrease in KM range of the battery. Points in favor of this explanation:
- Some users in the thread report that their real-world KM range is better than the reported battery health
- joxelitor's posts on page 5, testing the actual capacity of the battery in a home lab
- Shimano's official response that they investigated the issue and found that the battery health calculation is inaccurate and displays a lower value
- The oddly consistent and artificial/digital nature of the initial drop in battery health. As a software developer myself, the way users consistently see a drop to 90% battery health after 10 charges points to a software calculation issue. In a real-world hardware problem, these numbers wouldn't be so consistent and "perfect", I would expect to see a more linear degradation and more varied, analog numbers.
- Some users in the thread report that their real-world KM range matches the reported battery health
It is possible that explanation B is true and Shimano removed the value to cover up the problem and protect themselves from warranty claims, but IMO the evidence supports A. Especially joxelitor's testing, which is the only hard data in the thread.
Sorry for the long post, but I hope this helps some people finding this thread and worrying about their battery health.
Last edited:
Similar Threads
-
-
-
Sold 2022 Shimano BT-E8035 Battery $350 shipped- Started by Only_eMTBs
- Replies: 0
-
-
