Re-Build ande Re-Cell of Shimano Batteries

[Spiff]

There is very interesting information regarding batteries in the thread for E8000 Motor Repair:

STEPS E8000 Motor Service

In the end I put a thin washer under the C-Clip to reduce the axial play and I also replaced this bearing because it didn't spin as smoothly as the others, I lubricated everything well and for now, after 200 km, everything works as it did when it was new :) Hope it remains that way. I did the...

www.emtbforums.com

and forum member @fuikatasio has suggested not to mix topics and to open a new thread related only to batteries.

I am very interested in this, so I just followed his suggestion and here it is the new thread.

 

[johnf0246]

There is very interesting information regarding batteries in the thread for E8000 Motor Repair:

STEPS E8000 Motor Service

In the end I put a thin washer under the C-Clip to reduce the axial play and I also replaced this bearing because it didn't spin as smoothly as the others, I lubricated everything well and for now, after 200 km, everything works as it did when it was new :) Hope it remains that way. I did the...

www.emtbforums.com

and forum member FUIKATASIO has suggested not to mix topics and to open a new thread related only to batteries.

I am very interested in this, so I just followed his suggestion and here it is the new thread.

Spiff: is the Shimano Battery Rebuild info going to be posted in this new thread by FUIKATASIO?

 

[Planemo]

Interesting. Did it require some special connection with the BMS or did you just keep it fed with a slave voltage whilst you disconnected the power from the original cells?

 

[Spiff]

Spiff: is the Shimano Battery Rebuild info going to be posted in this new thread by FUIKATASIO?

I hope so.

 

[fuikatasio]

in process. Shimano battery restoration manual

 

[johnf0246]

in process. Shimano battery restoration manual
View attachment 103962

funk: are the front end and electronics showing from a different battery? I am curious how the black plastic case slides off the battery pack.

 

[lockin]

On TQ motor there is similar thread about battery cells replace and extending battery capacity. It work well for in-tube battery where there is no standard battery case but just battery packs group's together.

 

[fuikatasio]

Here I leave the tutorial that I created. I hope you can take advantage of it

 

[johnf0246]

Here I leave the tutorial that I created. I hope you can take advantage of it

Is anyone unable to download the pdf file for the battery restoration?

 

[irie]

Is anyone unable to download the pdf file for the battery restoration?

I just downloaded it no probs.

 

[Zimmerframe]

From @fuikatasio's PDF for anyone who can't download it - thanks and nice job ! :

 

[Spiff]

fuikatasio, thank you, you have done an amazing job!!

Shimano original batteries degrade very quickly, there are several reasons that could cause this, like:

• Bad quality cells.
• Full discharge of the batteries when shipping from Shimano factory to country distributors (To avoid safety hazards during shipping).
• Bad Design of BMS (HW or Firmware, not updatable) that damages batteries during the charge or discharge

So your re-cell could help to pinpoint the real issue. What happened to the batteries you did the re-cell, did they have less and slower degradation than the original Shimano ones?

 

[lockin]

@fuikatasio​

Question - since batteries are replaced and BMS stays the same then is the health battery percentage reset as well in application (apps that still show battery health like ST Unlocker etc.)

 

[fuikatasio]

@fuikatasio​

Question - since batteries are replaced and BMS stays the same then is the health battery percentage reset as well in application (apps that still show battery health like ST Unlocker etc.)

I can tell you that the battery before performing the cell restoration, on the handlebar display (in the Km BAT section) appeared 90%. Once the cells were changed, it appeared 100%.
Other tools like ST Unlocker I have not been able to use, because I do not have them.

 

[jimbob]

Many thanks for the excellent writeup. Have you tried it with an internal E8035 per chance?

 

[Spiff]

@fuikatasio you said that you use the Samsung 18650-35E, 3500mA cells. Where do you buy them, and is there a way to verify that they are Samsung original?

I am asking this because in China AliExpress it is possible to buy 18650-35E, 3500mA cells for 1,7€, but as there are many counterfait items in AliExpress may be they are not original. In Europe stores they cost around 5-6€.

Also, regarding the Battery Capacity, if the 40 Sony Murata Cells in 504WA Shimano Battery are 3500mA*h, the cell nominal voltage is 4,2V then the Battery Capacity should be:
40 * 3,5 Ah * 4,2V = 588W*h, may be I am missing something like efficiency or whatever.

Interestingly, if the cells were 3000mA*h, then the battery capacity would be:
40 * 3,0 Ah * 4,2V = 504W*h, which is the nominal capacity as stated by Shimano.

 

[fuikatasio]

@fuikatasio you said that you use the Samsung 18650-35E, 3500mA cells. Where do you buy them, and is there a way to verify that they are Samsung original?

I am asking this because in China AliExpress it is possible to buy 18650-35E, 3500mA cells for 1,7€, but as there are many counterfait items in AliExpress may be they are not original. In Europe stores they cost around 5-6€.

Also, regarding the Battery Capacity, if the 40 Sony Murata Cells in 504WA Shimano Battery are 3500mA*h, the cell nominal voltage is 4,2V then the Battery Capacity should be:
40 * 3,5 Ah * 4,2V = 588W*h, may be I am missing something like efficiency or whatever.

Interestingly, if the cells were 3000mA*h, then the battery capacity would be:
40 * 3,0 Ah * 4,2V = 504W*h, which is the nominal capacity as stated by Shimano.

the cells that I have used are original, purchased at nkon.nl
I do not recommend buying cells in China at all, as a general rule they are not original.
In nkon you also have restored cells, they are cells that have not passed the quality certificate, in terms of nickel welding.
But they are cells that have not had any charge cycle.

Samsung INR18650-35E 3450mAh - 8A - restaurado - 18650 - Li-ion - Pilas recargables | NKON

.

www.nkon.nl

Review the multiplication of the exact value in watts, I think you are taking the nominal voltage wrongly.
Its correct value is 3.6v
40 * 3,5 Ah * 3,6 = 504W*h
The advice I give you is that you buy the cells. Then you can someone who can place them for you.
So they will deceive us

 

[Spiff]

the cells that I have used are original, purchased at nkon.nl
I do not recommend buying cells in China at all, as a general rule they are not original.
In nkon you also have restored cells, they are cells that have not passed the quality certificate, in terms of nickel welding.
But they are cells that have not had any charge cycle.

Samsung INR18650-35E 3450mAh - 8A - restaurado - 18650 - Li-ion - Pilas recargables | NKON

.

www.nkon.nl

Review the multiplication of the exact value in watts, I think you are taking the nominal voltage wrongly.
Its correct value is 3.6v
40 * 3,5 Ah * 3,6 = 504W*h
The advice I give you is that you buy the cells. Then you can someone who can place them for you.
So they will deceive us

@fuikatasio Thanks, you are right, 3,6V is the Nominal Voltage and 4,2V is the Maximum Voltage that drops quickly to 3,6V

Actually I do not need to re-cell my batteries, one is at 88% and the other is at 100%. But I am planning in advance in case I have to re-cell the one that is at 88%. But I will do it by myself.

Can you please tell us how does the battery you re-celled degrade over time?, I mean, how many charge cycles did it take to start the degradation and how quick does it progress over time?. This would be interesting to understand why the original Shimano battery degrade so quickly

 

[fuikatasio]

@fuikatasio Thanks, you are right, 3,6V is the Nominal Voltage and 4,2V is the Maximum Voltage that drops quickly to 3,6V

Actually I do not need to re-cell my batteries, one is at 88% and the other is at 100%. But I am planning in advance in case I have to re-cell the one that is at 88%. But I will do it by myself.

Can you please tell us how does the battery you re-celled degrade over time?, I mean, how many charge cycles did it take to start the degradation and how quick does it progress over time?. This would be interesting to understand why the original Shimano battery degrade so quickly

These are things I do not understand. Being 3500mah sony murata cells, they degrade very quickly. I have replaced the cells when the battery was at 90%. The new battery with Samsung cells, I cannot assess its condition, since I have not used the ebike much in the last year

 

[Spiff]

@fuikatasio in your very nice document you say that Shimano Battery uses Sony Murata Cells of 3500mA*h, but by checking the battery Part Number in attached picture, the cells are Sony Murata US18650NC1, and I searched for the specifications, and looks like these cells are 2900mA*h, not 3500mA*h.

If this is true, then when doing the re-cell and using 3450mA*h Samsung 18650-35E cells, then the battery capacity increases by 19%, so the final capacity would be 504*1,19 = 600W*h.

As you are the expert, Can you please check if I am wrong

 

[fuikatasio]

@fuikatasio in your very nice document you say that Shimano Battery uses Sony Murata Cells of 3500mA*h, but by checking the battery Part Number in attached picture, the cells are Sony Murata US18650NC1, and I searched for the specifications, and looks like these cells are 2900mA*h, not 3500mA*h.

If this is true, then when doing the re-cell and using 3450mA*h Samsung 18650-35E cells, then the battery capacity increases by 19%, so the final capacity would be 504*1,19 = 600W*h.

As you are the expert, Can you please check if I am wrong

View attachment 106887 View attachment 106888

I see you are very interested in the subject, I'm glad.
I will clarify several things. I have already discarded several shimano batteries, 430w and 504w bt-e8010 battery.
It may be that the photo, which I have placed, was one of the 430w batteries.
To calculate the total watts of a battery, it is very simple.
504w-----> P = V x I = 36v x (4x3.5) = 504w
418w-----> P = V x I = 36v x (4x2.9) = 418w
630w-----> P = V x I = 36v x (5x3.5) = 630w

 

[Spiff]

@fuikatasio thank you for the clear explanation, I knew it was too good to be true, now my hopes went down the drain (In spanish: Mi gozo en un pozo, ja ja.).

Yes, I am interested in the subject and thanks to you I know how to do it. I have two batteries, a new 630W BT-E8016 and a 4,5 years old BT-E8010 FW 1.0.1.0 which is still performing well and degradation is only at 88% (With E8000 FW 4.8.0, not the newer 4.9.0 that improves the degradatation number).

But at some point my battery will increase the degratation and I am not willing to buy the newer BT-E8010 with "improved" FW 3.0.0.0 that degrades quicker than ever to 90% after 10 cycles. And after 3 years, Shimano has not fixed it, instead, they decided to hide the problem by changing diagnostics, documentation, and released new motor FW that substitutes the bad degradation number for a better one.

So now I am gettings my ducks in a row to be ready for when I have to replace the cells. I already purchased a very nice spot welder in Ali Express, for only 72€, it includes 10.000mAh internal battery, charger, solder pens. I already tested it and works well.

 

[robbydobs]

Thanks for posting this. I noticed a few things from the spec sheet

- the capacity drops significantly under load. e.g. capacity at 5A is only 2720mah rather than 3500mah.
I guess the e8000 on Boost / Turbo is about 500 watts -> 4A per cell.

- the capacity also drops very quickly after 50 cycles to 3000mah ish....

- The voltage drops in cold weather, but the effect on the overall capacity seems small. I guess it's just confusing the BMS which presumably relies on voltage...

I might have misinterpreted all the above as I'm no expert on all this, so feel free to correct me!

Info from here...

https://www.imrbatteries.com/content/sony_us18650vc7.pdf

What cells do other manufacturers use that don't have the capacity loss problem??

 

[richk]

Thanks for posting this. I noticed a few things from the spec sheet

- the capacity drops significantly under load. e.g. capacity at 5A is only 2720mah rather than 3500mah.
I guess the e8000 on Boost / Turbo is about 500 watts -> 4A per cell.

- the capacity also drops very quickly after 50 cycles to 3000mah ish....
View attachment 109325

- The voltage drops in cold weather, but the effect on the overall capacity seems small. I guess it's just confusing the BMS which presumably relies on voltage...

View attachment 109327
I might have misinterpreted all the above as I'm no expert on all this, so feel free to correct me!

Info from here...

https://www.imrbatteries.com/content/sony_us18650vc7.pdf

What cells do other manufacturers use that don't have the capacity loss problem??

The "capacity at 5A is only 2720mah" is probably just a mistake in the datasheet. The discharge diagrams on page 4 goes up to 8A which is still close to 3500 mAh.

In this review the 5A discharge test was not as good, but still around 3200 mAh.

Test of Sony US18650VC7 3400mAh (Green)

After bricking my BT-E6010 I was considering to upgrade to the larger capacity BT-E8010 battery, but I found out that it uses higher capacity cells which tend to have shorter service life and/or worse high current discharge characteristics. Batteries like many things are a balance of different parameters and compromises tuned for the given use-case (high capacity, high current, long life and low self-discharge).

Most Shimano battery packs use the lower capacity Sony US18650NC1 or similar cells around 2.9Ah. My BT-E6010 with these cells still had 90% of its capacity after 7 years (380 Wh at 2.5A discharge out of the 418Wh).

Shimano might have chosen the higher capacity cells for the top of the line BT-E8010 battery packs even if they knew they will fail sooner. I'm not sure if the BMS of the BT-E8010 would work well with the lower capacity cells, but for the sake of longevity it might be a better choice.

 

[SEBA]

is it possible to change bt 8020 capacity without changing the casing ?

 

[joxelitor]

Shimano might have chosen the higher capacity cells for the top of the line BT-E8010 battery packs even if they knew they will fail sooner. I'm not sure if the BMS of the BT-E8010 would work well with the lower capacity cells, but for the sake of longevity it might be a better choice.

It´s not Shimano, it´s Sony

Shimano batteries are manufactured by Sony Wuxi (china division) so, Sony-Murata cells is a logic selection.
Information is reliable, the source is the UN 38.3 test report for transportation safety

 

[Aguinier]

@fuikatasio : this is simply genius, thank you very much for this very detailed insight.
I still have a question related to the process. I was wondering what was the risk during the removal of the nickel plate, is it a short circuit ? Is it more than that? I also do not understand exactly what do we have to be careful about?

Thank you for your lights!

 

[fuikatasio]

@fuikatasio : this is simply genius, thank you very much for this very detailed insight.
I still have a question related to the process. I was wondering what was the risk during the removal of the nickel plate, is it a short circuit ? Is it more than that? I also do not understand exactly what do we have to be careful about?

Thank you for your lights!

Very simple, the nickel strips are welded in areas. When removing the nickel from one of those areas with pliers, you can never touch the nearby area. I assure you that you are going to get a good scare

 

[joxelitor]

@fuikatasio : this is simply genius, thank you very much for this very detailed insight.
I still have a question related to the process. I was wondering what was the risk during the removal of the nickel plate, is it a short circuit ? Is it more than that? I also do not understand exactly what do we have to be careful about?

Thank you for your lights!

You can accidentally make a short with nickel fragments scattered around the workbench.
The tip of the pliers tends to break in this type of work. You don't want metal fragments falling on a LiIon battery

There is another risk, which is not usually discussed: breaking the battery case.
Depending on the penetration of the spot weld, you can tear some of the material out of the cell container and that's a big problem if your face/eyes and hands are right on top of that "bomb".