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Custom Bosch / Yamaha battery

Posted: Jun 12 2015 10:10am
by dusan
Hello,
Did anybody disassemble original Yamaha battery?
There are three connectors coming from battery, when fully charged 0V, 40V and 42V. Seems they are using 10s4p 2900 Li ion cells.
Could be possible to replace them?
Thanks.

Edit:
https://www.pedelecforum.de/forum/index ... ing.39480/

Re: Custom Bosch / Yamaha battery

Posted: Jun 12 2015 1:18pm
by Nobuo
the pack inside it will be highly probably spot welded, so you need to open and figures how the pack is mounted. Then you could take the BMS you will find connected inside to the pack and even use it in the new pack if you will dispose the cells.

As that cases are some times sealed, maybe you can't open and close again as it was before, so you maybe have to seal the pack again.

Be very careful opening the case, is too easy to short cells and conudctors if you use some like a screw driver

Re: Custom Bosch / Yamaha battery

Posted: Jun 12 2015 2:45pm
by dusan
Thank you Nobuo,
Can you please confirm my previous guesswork?
Are there really 10s4p 2900mah Li ion cells?
I'm using only Economy mode, so my current requirements are only up to 8 Amps. I additionally geared previous configuration with 42t rear sprocke, so 38t front and 42t rear within 29" wheels.
https://www.e-bikeshop.co.uk/Haibike-sD ... ne-RC-2015
I am very happy with bike at all but I can't achieve over 80km in XC terrain with Economy mode.
I was thinking to change 2900mah with Panasonic 3400mAh.
Also, why is there third connector pin with only 40V? To balance battery voltage drop? Actually I didn't notice voltage drop on output power.

Re: Custom Bosch / Yamaha battery

Posted: Jun 13 2015 5:23am
by Punx0r
Unfortunately you have experienced the normal marketing (lies) for ebike range specification ;) Your battery is of modest capacity and the 80Km range will be based on flat, smooth ground, low speed and very minimal assist from the motor (basically, nearly all pedalling).

Upgrading to 3500mAh cells might work. This would give you ~500Wh of capacity, which should increase your range by 25%. Would this be enough?

Re: Custom Bosch / Yamaha battery

Posted: Jun 16 2015 1:23pm
by dusan
Punx0r wrote:Unfortunately you have experienced the normal marketing (lies) for ebike range specification ;) Your battery is of modest capacity and the 80Km range will be based on flat, smooth ground, low speed and very minimal assist from the motor (basically, nearly all pedalling).

Upgrading to 3500mAh cells might work. This would give you ~500Wh of capacity, which should increase your range by 25%. Would this be enough?
yes, that would help
as i wrote, i don't need much current, just to increase capacity
I've understood, speak about assistance below 5Wh/km is nonsense.

Re: Custom Bosch / Yamaha battery

Posted: Jun 16 2015 3:33pm
by Punx0r
nkon.nl is a good EU supplier of genuine 18650 cells, they have several in the 3400-3500mAh range.

What is the maximum power (watts) or current (amps) draw of your bike?

Re: Custom Bosch / Yamaha battery

Posted: Jun 16 2015 4:37pm
by silentflight
That looks like a very nice bike. I've ridden a 2014 Bosch Haibike and thought it was great, just wish it wouldn't stop the assist when you ride even somewhat fast. I found myself "riding over the top of the motor" if that makes sense to you. Essentially 90% leg power and 10% motor power just above the speed cutoff. I still thought it was a great bike, and will consider buying one when I know that I can disable the speed limiter.

How much did you pay for your bike and where did you buy it? Would be interested if it were available at better than list prices.

I've thought about how I would handle the battery situation, as I ride long distances. I ride a large cargo bike and average 7.5 Wh/km with a hub motor. With a lighter bike like yours and a mid-drive motor running in its sweet spot for efficiency I might get 6 Wh/km, but not much below that. I obviously like to pedal. I think I would buy a second battery to start with if I were you, but I know they are expensive. I wouldn't replace the cells in the battery that came with it- for another option I might make a second 10S 18650 pack to connect to it in parallel and keep it on a rear rack or in a pannier bag with a wire running up to the original battery on the down tube. This would involve opening the battery to solder on wires to connect to it in parallel and a hope that the BMS would tolerate the extra amp hours during discharge. I would charge them separately. Good luck with whatever route you choose, and have a blast riding it.

Re: Custom Bosch / Yamaha battery

Posted: Jun 23 2015 4:35pm
by dusan
Thanks silent, it's great idea to have another battery in parallel but I ride XC. I am using Economy mode and I can tell, I usually support 50W, rest coming from motor. It's pretty enough after 38t / 42t upgrade. Yeah, I think to upgrade cells with more capacitive, 3500mAh or more. I will probably do it after battery warranty.
Max power should be around 700W, but I very unusually used it. I am riding up to 100% assistance, up to 250W, below 7 Amp.

Re: Custom Bosch / Yamaha battery

Posted: Jun 23 2015 6:36pm
by Syonyk
Without opening the pack, you can't tell what the configuration is. It will be 10S almost certainly, but the parallel configuration will depend on the cells used. It could be 4P, it could be 5P with 2200mah cells (which, if I had to guess, I'd say is more likely - most commercial packs use the cheap cells, which are usually lower capacity).

Most packs can be rebuilt with higher capacity, but it's a somewhat involved project, involving spot welders, soldering irons, and a non-trivial bit of skill.

One thing to be aware of is that at least some of the higher capacity 18650s are not 4.2v cells - they're fully charged at 4.35v, which means if you charge to 4.2 per cell, you're not getting the full rated capacity. If you're coming from 2200mah cells, it's still a nice improvement in capacity, but check the discharge curves to see how much you're actually getting at 4.2v/cell.

Re: Custom Bosch / Yamaha battery

Posted: Jun 24 2015 5:56am
by Malloot
Syonyk wrote:Without opening the pack, you can't tell what the configuration is. It will be 10S almost certainly, but the parallel configuration will depend on the cells used. It could be 4P, it could be 5P with 2200mah cells (which, if I had to guess, I'd say is more likely - most commercial packs use the cheap cells, which are usually lower capacity).

Most packs can be rebuilt with higher capacity, but it's a somewhat involved project, involving spot welders, soldering irons, and a non-trivial bit of skill.

One thing to be aware of is that at least some of the higher capacity 18650s are not 4.2v cells - they're fully charged at 4.35v, which means if you charge to 4.2 per cell, you're not getting the full rated capacity. If you're coming from 2200mah cells, it's still a nice improvement in capacity, but check the discharge curves to see how much you're actually getting at 4.2v/cell.
Not all 3500 or 3200 cells are 4.35V
http://www.dampfakkus.de/akkutest.php?id=577
http://www.dampfakkus.de/akkutest.php?id=537

I have opened Bosch packs they are 4p 2900 cells from Samsung, i am guessing that Yamaha uses the same cells. Both brands do not seem to want to go bigger size physically because of marketing and cleaner looks. Problem is that many customers do want bigger packs for higher range. Bosch actually makes high speed versions up to 45kmh support. Its a shame Yamaha doesn't do that as i like there systems support from 0 rpm more.

BTW i removed the speed sensor from one of the Yamaha bikes in the shop, unlike Bosch it still works and I was hoping to get unlimited support. However I was surprised to find support still stops at roughly 25kmh, no idea how they figure the speed out because the cadence is not a give away...

The best bet you have on increasing you range is just buying another pack and taking it with you, i would be hesitant to risk destroying your expensive pack and removing warranty of 500 charge cycle's. It might be expensive but thats the problem of buying the brand stuff, they overcharge you for that shit. LG MH1 cells alone would give you 1kwh for about 300 dollar but then you'd have to make the pack yourself

Re: Custom Bosch / Yamaha battery

Posted: Jun 24 2015 8:19am
by Syonyk
If it is a 4p pack using 2900mah cells, there's really not much additional capacity you can cram in. Going from 2200mah cells to 3200-3500mah cells is a significant upgrade, but going from 2900mah to 3200-3500 is probably not worth the effort.

Re: Custom Bosch / Yamaha battery

Posted: Sep 24 2015 2:56pm
by dusan
Now I am not sure.
Yamaha battery is 500g heavier and warranty cycles are 700, two times more than Bosch.
There actually could be 10s5p configuration as 10 cells with 50g are 500g over.
Then it could really make a sense to buff it with 3500mAh cells. But I still worrying about warranty, I would probably need to buy spare one for service / warranty purposes.
So far I have 3.000km done, there is some capacity loosed but still fine. I guess, I could charge it around 50 times.

Re: Custom Bosch / Yamaha battery

Posted: Dec 04 2015 1:27pm
by dusan
Regarding speed limit, there is a cheap solution
https://youtu.be/K8yF6mzg2aw
I didn't try since I'm riding mostly XC and don't feel need to ride faster but for road it could be definitely first approach I would try.

I looked at battery, because warranty said 1 year or 700 cycles and still over 50% original capacity, waiting for 50% of capacity is wasting of weight and time for me. I will probably go for another pack and experiment with current one. Looks like well assembled and after unsoldering PBC, cells could be replaced.

After around 4.000km, battery has started to be weak at 15% of remaining capacity. I did maybe around 100 cycles.

Re: Custom Bosch / Yamaha battery

Posted: Jan 15 2016 2:47pm
by dusan
So, it seems, my problem was solved by neoprene cover for battery and charging at room temp.

Re: Custom Bosch / Yamaha battery

Posted: Jan 15 2016 4:58pm
by spinningmagnets
Thank you for posting this, please take many pictures of all the details...

Re: Custom Bosch / Yamaha battery

Posted: Mar 27 2017 3:52am
by mwerme
Dusan, did you by any chance take any additional pictures of the external connectors and how they connect inside the battery pack? Trying to use an identical pack to power a different e-bike but need to know which connectors to use.

Re: Custom Bosch / Yamaha battery

Posted: May 10 2017 9:15am
by tumich
Did anybody try to make 'custom additional battery' compatible with Bosch CX?

Re: Custom Bosch / Yamaha battery

Posted: May 10 2017 11:09am
by Voltron
Bosch pack internals fwiw..
bosch.jpg
bosch.jpg (71.74 KiB) Viewed 8106 times
packopen.jpg
packopen.jpg (56.18 KiB) Viewed 8106 times
boschbms.jpg
boschbms.jpg (53.87 KiB) Viewed 8106 times

Re: Custom Bosch / Yamaha battery

Posted: Jul 05 2017 3:16pm
by gamerpaddy
sorry for late post.
but i reverse engineered the yamaha battery a year ago.


in case you want to build your own.
Just get a Arduino compatible board and a few discrete components.

Add a 5V source, i usually use a LM2596HV dc dc converter for this. A USB powerbank or even running it from two or three Cells on the pack (VIN pin of the arduino) will work.

Optional: To monitor the voltage add a voltage divider set to a ratio of 7.401 (42v in 5v out) and connect it to the A0 pin of the Arduino.

Edit this code https://pastebin.com/34SdehGt
>Edit line 35 to match your voltage divider. calculate or test to find out ADC values.
>Change line 44 and 45 (the number 20) to a value you want. 20 means it averages the current voltage 20 times to smooth it out. 20 is 5 seconds.
>Remove line 50 if you dont want your indicator to stay at 10% even if its lower. this prevent turning the motor off when voltage drops driving up a hill.

After that, Flash it in Arduino IDE

Wire it up like this.
Image

Some people including me allready did it to the haibikes, works great. See german pedelecforum.
If its too much for you, a guy called Cosas in pedelecforum is selling modules based off my code that does exactly this, basically dongles you put on the Battery connector and can connect any ordinary 36V Battery onto it.


Havent done anything on Bosch so far, i dont have Bosch.

Re: Custom Bosch / Yamaha battery

Posted: Nov 24 2017 4:39am
by Daniel...
hi guys i have problem. i dont know wich wire from charger fits to wire in battery. i change destroyed connector but i dont check it. there is four connectors from battery : white/blue and red/black from charger: black/yellow and red/blue ....somebody helps wich one from battery fits to wich one from charger thanks

Re: Custom Bosch / Yamaha battery

Posted: Apr 28 2018 3:41am
by ulikus
gamerpaddy wrote:
Jul 05 2017 3:16pm
Havent done anything on Bosch so far, i dont have Bosch.
Hi! Got a Bosch Classic battery.
Want to make a replaceable BMS for it, but don't know where to start. (got programming knowledge and abit of EE-can wire and program arduino) just need to understand how to read data from battery )

Re: Custom Bosch / Yamaha battery

Posted: May 20 2018 9:06am
by Rumberopie
Hi!
I try this circuit but don't work!
can you tell me the exact components you used?
Thanks

Re: Custom Bosch / Yamaha battery

Posted: May 20 2018 1:25pm
by Joachim
the rackpack Yamaha 500wh battery is a hel of a job :shock: a no go for hobby builders trust me :wink:

Re: Custom Bosch / Yamaha battery

Posted: Dec 02 2018 10:47am
by attila
gamerpaddy wrote:
Jul 05 2017 3:16pm
sorry for late post.
but i reverse engineered the yamaha battery a year ago.


in case you want to build your own.
Just get a Arduino compatible board and a few discrete components.

Add a 5V source, i usually use a LM2596HV dc dc converter for this. A USB powerbank or even running it from two or three Cells on the pack (VIN pin of the arduino) will work.

Optional: To monitor the voltage add a voltage divider set to a ratio of 7.401 (42v in 5v out) and connect it to the A0 pin of the Arduino.

Edit this code https://pastebin.com/34SdehGt
>Edit line 35 to match your voltage divider. calculate or test to find out ADC values.
>Change line 44 and 45 (the number 20) to a value you want. 20 means it averages the current voltage 20 times to smooth it out. 20 is 5 seconds.
>Remove line 50 if you dont want your indicator to stay at 10% even if its lower. this prevent turning the motor off when voltage drops driving up a hill.

After that, Flash it in Arduino IDE

Wire it up like this.
Image

Some people including me allready did it to the haibikes, works great. See german pedelecforum.
If its too much for you, a guy called Cosas in pedelecforum is selling modules based off my code that does exactly this, basically dongles you put on the Battery connector and can connect any ordinary 36V Battery onto it.


Havent done anything on Bosch so far, i dont have Bosch.
Please help me with the Yamaha 500 wh battery. It has 3 pins connecting it to the engine, I do not understand why. I would like to build a bigger battery than the yamaha 500 wh without a bms, but I do not understand how to connect it.

Re: Custom Bosch / Yamaha battery

Posted: Mar 22 2019 12:52am
by Pwnlord187
If you bypass the discharge on your Yamaha battery pcb (cut the thick red/black wires going to the board from the discharge port, and solder them to the main leads of the pack, which are oval shaped solder pads on each end, the one closest to the port is positive) if you do this you won't be restricted by yamahas discharge limits, which are set to be overly conservative compared to how the cells can actually perform