Shimano BT-E8035 Integrated Battery Issue: very fast degrading and loss of range

[Deimos]

Thats exactly how i handle it still annoying

 

[Spiff]

Okay, so if it's software then maybe forget it, stop checking the battery "health" with aftermarket apps such as Stunlocker and just ride the bike?

Software issue does not mean that software is reporting an incorrect low Battery Health but in reality the cells and battery have a good health and the range is as good as new.


Sofware issue means that the firmware in BMS Microprocessor is defective and does an incorrect charge or cell balancing, thus irreversibly damaging the cells in the battery and causing the health degradation. As Shimano Software Designers are so non-smart (I am trying to be polite here), besides of the incorrect programming they made the BMS Firmware not upgradable, and after 2 - 3 years since this problem arised, they have not fixed it and looks like they will never fix it.

Instead of fixing the issue, Shimano has chosen the approach of masking it by:
- Eliminate the Battery Health diagnostic in newer versions of etube
- Make a software upgrade V4.1.8 for EP800 motor that fakes the Battery health reported by the battery to a better health.
- Not attending the Battery Health warranty claims

 

[lightning]

I don't doubt you are correct.
Nobody's answering my other question though.

Are you seeing an actual decrease in range coinciding with the reducing battery "health" on the app?

 

[Spiff]

I don't doubt you are correct.
Nobody's answering my other question though.

Are you seeing an actual decrease in range coinciding with the reducing battery "health" on the app?

Yes, I see a decrease in range. I keep the GPS track of all my rides together with the battery statistics and the range decreases similarly to the decrease of the battery health.

Besides that if I were to sell my battery, the buyer would ask for the current battery health, and the market value of the battery also decreases.

 

[Deimos]

I really Like the Shimano Steps system. Owned an e8000 an now Ep8 but next ebike will be from a other brand. Mainly because they handle problems the way they do it with the battery issue right now. Not very comsumer oriented.

 

[Spiff]

I really Like the Shimano Steps system. Owned an e8000 an now Ep8 but next ebike will be from a other brand. Mainly because they handle problems the way they do it with the battery issue right now. Not very comsumer oriented.

I also like Shimano Steps:

• Small display
• Waterproof and compatibility of the cabling.
• Integration of all the components.
• Documentation

But what I do not like in Shimano Steps is far more important:

• Battery Degradation and bad design with no FW update possibility
• Motor absolutely non repairable and spare parts are not sold by Shimano. Any minor issue or cheap part broken means to spend 1000€ in a new motor.
• Customer relationship and warranty Handling

Do I need to say that my next ebike will not have Shimano Steps...

 

[lightning]

No spares for the motor? That's bad, l didn't know that
l think you can get bearings though, because there's a company advertising bearing replacement.

Probably Bosch for me next time though.

 

[mad115]

Are the batteries actually degrading by the reported amount then?

Yes. Battery health % values are get from the application. As of March 2022.

 

[mad115]

I don't doubt you are correct.
Nobody's answering my other question though.

Are you seeing an actual decrease in range coinciding with the reducing battery "health" on the app?

Yes. Of course, I see a shorter range.
Since I often drive the same circuit (25 km uphill 1000 altitude meters and then back 20 km down),
I know the following: In the first months of ebike, I passed this circuit twice on one charge
(one day circuit, and then the next day again and only then charging).

Today (after 4500km and 50 recharging cycles), the battery is no longer enough for the second trip and I always have to recharge after one circuit.

 

[mad115]

in the case, that my ebike has still the same range on road, even though battery health shows anything, I'm not crying here and I'm just riding a bike in the mountains ..

 

[Pivot]

Fine and gr8, but your battery is BT-E8036 and this thread is about a different model. BT-E8035 drops down to 90% when you have 10 cycles.

Slightly off-topic… my E8036 battery dropped to 98% health after 10 cycles and 1190km… I can live with that.

 

[lightning]

l'm going to stop even checking the "health" of my battery, so long as l get at least 30 miles of range out of it.

When new l could get around 35 miles.

 

[surfperch61385]

I wrote here back in November. My motor had overheating issues, power fade and power to the drive unit would cut in and out. On top of all that my range would decrease by something like 1/10th of a mile every time I took it out. Finally got shimano to replace the battery, problem solved.

 

[jimbob]

I wrote here back in November. My motor had overheating issues, power fade and power to the drive unit would cut in and out. On top of all that my range would decrease by something like 1/10th of a mile every time I took it out. Finally got shimano to replace the battery, problem solved.

May I ask how you went about getting the replacement agreed? And was that in the UK?

 

[surfperch61385]

May I ask how you went about getting the replacement agreed? And was that in the UK?

Im in the US. Took 8 months dealing with a qualified mechanic. He finally gave me the number and name of the shimano rep he had been dealing with and told me I should try telling him what ive been dealing with. I called the shimano rep and explained everything in detail, he agreed that it was most likely a bad battery.

 

[lightning]

l didn't have so much trouble, l sent my battery back to the shop because the status was 77% after 60 charge cycles.

l had to answer a couple of questions such as how often was the bike used. A new battery was sent after about two months.

 

[Deimos]

I wrote here back in November. My motor had overheating issues, power fade and power to the drive unit would cut in and out. On top of all that my range would decrease by something like 1/10th of a mile every time I took it out. Finally got shimano to replace the battery, problem solved.

I have a similar problem with my motor ATM.
Did they warranty the motor too or was it your battery that caused the motor problem?

 

[joxelitor]

Do I need to say that my next ebike will not have Shimano Steps...

Hope that happens soon, really. You will stop loosing years of life blaming Shimano all over the internet.

You know! I had problems with my motor, had to repair it by myselfm but it´s now 1600 Km of playfullness and joy if ride...and much much less posting about Shimano in this and other forums

Hope your karma gets a bearings swap, you deserve it We too

 

[Zimmerframe]

Hope that happens soon, really. You will stop loosing years of life blaming Shimano all over the internet.

Hope your karma gets a bearings swap, you deserve it We too

Really ??? You waste your life taking the time to complain about someone saying they've had poor experience with Shimano ??

Your own first message :

"Hola Muy buenas
Espero que nos podamos poner en contacto, yo te queria pedir ayuda sobre el mantenimiento del motor shimano e8000, y tu quizas quieras que te pueda ofrecer mis conocimientos sobre la restauracion de celdas en la bateria bt8010.
Un saludo"

"Hello Very good I hope we can get in touch, I wanted to ask you for help on the maintenance of the shimano e8000 engine, and you may want me to offer you my knowledge on the restoration of cells in the bt8010 battery. All the best"

Not exactly arriving to point out all the positives of the Shimano motor and battery ??

Your own motor experience :

"Mine was donde with only 3500Km, and after 100km more had to replace all bearings, not only the ones on the pedal shaft, it was not a problem of water ingress or bad quality of the bearings (NSK)"

You seem like a talented guy, but not everyone wants to buy from Shimano if there slogan is :

"SHIMANO, Gives you hours of fun on the bike and hours of fun rebuilding your motors and batteries because we'll do anything possible to make our warranty figures look good"

For the battery issues, you have the skills and equipment to fix these things yourself :

"It´s only possible with laboratory mesaruments directly on the battery using a dc load and datalogger.
Fortunately i have both, the lab and a new battery so in the next months i plan to start using it and tracking capacity on the lab vs life indicated on the Shimano Display"

Not everyone does and in reality, no one should have to ?

 

[Spiff]

Hope that happens soon, really. You will stop loosing years of life blaming Shimano all over the internet.

You know! I had problems with my motor, had to repair it by myselfm but it´s now 1600 Km of playfullness and joy if ride...and much much less posting about Shimano in this and other forums

Hope your karma gets a bearings swap, you deserve it We too

I do not pay attention to what he says, he is just a grumpy person looking to create conflicts where they dont exist so I just ignore him, but looks like this infuriates him even more and chases me and my posts in forums, and he even digs up a three month old post just to explain how good and smart he is and how stupid I am.

 

[Milan]

Yes, I see a decrease in range. I keep the GPS track of all my rides together with the battery statistics and the range decreases similarly to the decrease of the battery health.

Besides that if I were to sell my battery, the buyer would ask for the current battery health, and the market value of the battery also decreases.

Spoken to a guy who has got two bikes with the same model of the battery, both the batteries have been degrading the same way: after 10 cycles drop to 90% health and losing range in line with the decreasing health. Used his warranty when below 80% but was refused. Mine was accepted below 80%. I got a new battery and when it dropped from 100% to 90%, after only those 10 cycles, I was asked to come and update the drive unit firmware (June 2022). After the update, health increased from 90% to 94% )) Most people I have talked about this issue confirm Spiff's version: it is the BMS that makes the cells degrade fast. I got in touch with a battery manufacturer who also recell depleted ones and he said you could get any kind of cells there are and the BMS will always degrade it since the firmware follows the same algorithm.

 

[AusE]

Spoken to a guy who has got two bikes with the same model of the battery, both the batteries have been degrading the same way: after 10 cycles drop to 90% health and losing range in line with the decreasing health. Used his warranty when below 80% but was refused. Mine was accepted below 80%. I got a new battery and when it dropped from 100% to 90%, after only those 10 cycles, I was asked to come and update the drive unit firmware (June 2022). After the update, health increased from 90% to 94% )) Most people I have talked about this issue confirm Spiff's version: it is the BMS that makes the cells degrade fast. I got in touch with a battery manufacturer who also recell depleted ones and he said you could get any kind of cells there are and the BMS will always degrade it since the firmware follows the same algorithm.

So is the BMS located in the battery?
If so I'm wondering if it would be possible to use internals from say a norco battery which are not shimano and put in the bt-8035 case.
Only theorising here as I have no idea if this would be possible.

 

[AusE]

the bms is in the batt case but it uses can bus encryption to lock there batts to there motors and displays so you cant recell the batts as if you cut power to the bms it looses its can bus programming and bricks it.

but a batt with a decent bms will not loose 10% of its capacity over 10 charge cycles so there software and bms are shit.

So how do norco and others that use shimano motors but other manufacturers batteries get around this. Also noticed that merida have a bike with a simple 750w battery which is interesting.

 

[Milan]

So is the BMS located in the battery?
If so I'm wondering if it would be possible to use internals from say a norco battery which are not shimano and put in the bt-8035 case.
Only theorising here as I have no idea if this would be possible.

Yes, it is. I was wondering the same way but the recell manufacturer and a guy who retrofits engines to old school bikes told me they would not mess around with the bms since Shimano and their proprietary system uses very "lively" communication between the battery and drive unit and they might end up having the unit damaged or blocked. I am not an expert, I cannot support it anyhow. My belief is that it is possible to replace the bms but you definitely have to know a lot about the Shimano combo. How it is coded/designed. On the other hand, the guy with the two degraded batteries promised to send me links for replacement batteries which are costly (eur 800), however, non-Shimano.

 

[jimbob]

My understanding is that the shimano battery BMS will indeed 'brick' itself if you remove power such as when trying to re-cell, but the battery doesn't need to communicate with the motor via can bus to work. To wake it up it reduces the resistance on one of the communication pins to the 0v line. That's how other manufacturers can use non shimano batteries.

So, in theory it is possible to replace the cells in a shimano battery, but you would also need a new bms. The problem would be finding one which would fit in the same space as the original.

 

[Milan]

My understanding is that the shimano battery BMS will indeed 'brick' itself if you remove power such as when trying to re-cell, but the battery doesn't need to communicate with the motor via can bus to work. To wake it up it reduces the resistance on one of the communication pins to the 0v line. That's how other manufacturers can use non shimano batteries.

So, in theory it is possible to replace the cells in a shimano battery, but you would also need a new bms. The problem would be finding one which would fit in the same space as the original.

The manufacturer had no problem recelling it, he was not particularly happy about Shimano, but he implied issues when replacing the BMS. No problem recelling (costs a little bit less than a new/original one) but with the same BMS, it will follow the same degrading pattern.

 

[jimbob]

Have they done them before? I'm sure someone else on here tried it and found out it wasn't possible as the BMS would break when battery power was removed?

The issue could be from poor cells rather than the BMS though, and the actual issue of degradation may not be as bad as reported by the BMS, so a re-cell may be a good option.

I've been tracking the actual battery degradation over the last 100+ cycles and have been meaning to write the results up on here for a while. If I get a chance, I'll do it later.

 

[Milan]

Have they done them before? I'm sure someone else on here tried it and found out it wasn't possible as the BMS would break when battery power was removed?

The issue could be from poor cells rather than the BMS though, and the actual issue of degradation may not be as bad as reported by the BMS, so a re-cell may be a good option.

I've been tracking the actual battery degradation over the last 100+ cycles and have been meaning to write the results up on here for a while. If I get a chance, I'll do it later.

What you are saying contradicts to what the recelling guy told me. I am not saying that you may not be right. He told me whether you use Panasonic or Samsung cells, which most of them do, you will end up having the original BMS that follows a pattern. I have been tempted to try this one out but it would cost me 500 eur. And then I thought why do not I sell this crap soon enough before it is too late again Anybody here with a hands-on experience on Shimano BMS (replacing/updating/reworking/hacking) and this particular battery?

 

[Milan]

Shimano E-Bike Akku Reparatur – Fachgerechte Fehlerbehebung

Schnelle und kostengünstige Shimano E-Bike Akku Reparatur bei Liofit. Wir bieten Zelltausch, Elektronikreparaturen und verlängern die Lebensdauer Ihres Akkus.

www.liofit.com

that is the only company in the world that can recell some of these can bus bms boards but even if they can do it if power is cut to the bms it looses its programming and as you can see they wont do these batts.

like everything these days they expect you to just throw it in the bin and buy a new one and make it so hard to fix with software locks it makes it near impossible as well as not selling any parts to fix anything either like a bms or a controller or even bearings.

like giant they use the Yamaha motors but they make there own controllers bms and displays to lock them to there brand a normall yamaha controller will not work in a giant yamaha motor.

Yamaha Motor Parts - eBike Motor Centre (Performance Line Bearings)

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www.ebikemotorcentre.com

that controller uses uart coms and not can bus but they still wont sell the bms for those batts but there is a hack so you can use a normall bms with a coms chip in-between the batt and the motor.

Yamaha mid-drive motor dongle to use 3rd party batteries

Here, I share technical solutions that arised during the development of my solar-bike.

www.avdweb.nl

If this is so, we are all s......d with this particular model and the only thing you can do, is to use your warranty or a solicitor when they decline to offer a replacement.

 

[Milan]

i have a 400w bosch batt from 2014 that needs to be recelled but even tho liofit can do it postage to germany and back is not a option as it whould cost even more than one from bosch in the uk.

so it is not just shimano it is all of them and when you have no warranty at all it gets expensive fast but the 2 year warranty is not long enough esp with the price of these things hitting 10k plus it should be 5 years at least.

How many kms have you made with the bosch? Mine was replaced at 5400 km and the bike kept turning off randomly for the past 1000 km for no obvious reason. This amounts to 0.12 eur/km or so which is something for my Honda PCX which covers gas/km, yearly theft and crash insurance plus yearly checkups and planned repairs and replacements.