Battery packs in Ruk sacks or back packs for Bafang M620 with X1 controller.

[technotony007]

Hi,

After going through the usual expensive route of trying source use different types of Fake chinese sourced ah batteries. The ebike i use seems to drain them pretty quickly. It had wrecked two BMS's , to which i had to remove them and then it cooked the both batterys , as they got unsafely hot. I am thinking about building and a large square 52V 50ah with 21700 cells, sized battery for my Vapour ebike. My plan is put this put this in a ruksack or backpack. I have seen another system that that does this also, this is the Paradox Kinetics system.

We queries to start off this Thread is :

1. has anyone else done this before ?
2. what precautions did they take , in case of failures ?
3. what size of batteries did they use ?

I am using the Bafang M620 G510 unit , which has been upgraded with The X1 controller , and has larger 60 A power cables fitted to it.

if anyone out there uses this X1 controller on their bafang unit , please can you let me know which size and type of battery consturction they use also ?

Any help , thoughts , contributions in ideas to this would be greatly Appreciated.

 

[amberwolf]

1. has anyone else done this before ?

If you mean backpack/rucksack/non-hard-mounted batteries, sure. There's a number of threads and posts about them; here's one possible search using the archived version of ES

ES 1.0 Graveyard - Search

looking just for "backpack batter*" in the first post or title of a thread.

2. what precautions did they take , in case of failures ?
3. what size of batteries did they use ?

Some take no precautions, just shoving them in the backpack, some have elaborate padding/etc., some have special cable or connector setups to prevent disconnection or allow it to happen more easily.

All sorts of batteries have been used, from RC packs to cylindrical to prismatic, premade and DIY.

Hi,

After going through the usual expensive route of trying source use different types of Fake chinese sourced ah batteries. The ebike i use seems to drain them pretty quickly. It had wrecked two BMS's , to which i had to remove them and then it cooked the both batterys , as they got unsafely hot.

Sounds like the bike uses more current and capacity than the batteries can handle. See below.

I am using the Bafang M620 G510 unit , which has been upgraded with The X1 controller , and has larger 60 A power cables fitted to it.

if anyone out there uses this X1 controller on their bafang unit , please can you let me know which size and type of battery consturction they use also ?

How much current can the controller demand, maximum, both peak and continuous? Not how much the cables can handle, but the actual measured current it draws under your worst-case riding conditions.

Your battery must be able to easily handle this, so it's construction and size must accomodate this.

What is your Wh/mile (or Wh/km) capacity usage, under worst-case riding conditions?

I recommend sizing it so that the cells in the pack are not stressed in any way, either by demand of current, or by how much capacity they have vs how much you need to use, worst-case, so that they are never discharged too far, and do not have to be fully charged to supply all the capacity you need.

 

[technotony007]

Thanks Amberwolf , appreciate your comments. , i m not sure what my Wh/mile would be due to the batterys i had and there unreliable Ah rating.They both were 52v 20Ah , that i thought would of been good enough. I was contenplating using 14s , 18p version with these.....



I also thought about a specailist battery builder. who i could buy one off the UK.....

do you or anyone else know of someone reliable ?

regards

Tony

 

[seanchad]

I've just had Jimmy from ebikebatteries.co.uk build me a 52v pack using Samsung 50s cells for my cyc x1 Stealth which uses the x6 controller.

 

[99t4]

I was contenplating using 14s , 18p version with these.....
View attachment 336350

252 21700 cells in a backpack? That you are going to wear on your back while riding?

 

[amberwolf]

252 21700 cells in a backpack? That you are going to wear on your back while riding?

At an average of 60g / cell, that's 15120g, 15.1kg, or 33.3lbs. Add a few more kg for backpack itself, casing, padding, interconnects, wires; call it 20kg at the high end?

Pretty hefty, but I guess if you have a good back and legs it's not too bad. When I was young I probably carried that much in books or other stuff riding around; I just tried not to hit any bumps. I couldn't even put such a backpack on these days, though.

 

[E-HP]

At an average of 60g / cell, that's 15120g, 15.1kg, or 33.3lbs. Add a few more kg for backpack itself, casing, padding, interconnects, wires; call it 20kg at the high end?

Pretty hefty, but I guess if you have a good back and legs it's not too bad. When I was young I probably carried that much in books or other stuff riding around; I just tried not to hit any bumps. I couldn't even put such a backpack on these days, though.

Besides those health benefits for your back and legs, it's a great deterrent from taking those leisurely rides, quick outings and short errands; plus no worries about getting the battery stolen when parked.

 

[amberwolf]

Thanks Amberwolf , appreciate your comments. , i m not sure what my Wh/mile would be due to the batterys i had and there unreliable Ah rating.They both were 52v 20Ah , that i thought would of been good enough. I was contenplating using 14s , 18p version with these.....

Is your bike this?

KirbEbike VAPOUR – Bournemouth Performance Electric Bikes

www.bpeb.co.uk

Motor: Bafang M620 MID-DRIVE 48V/1000W with Colour LCD
Battery: 48V/14Ah LG MJ1 battery
PAS: Torque + speed sensor
Controller: 48V Intelligent brushless controller
Display: BAFANG LCD
Top Speed: below 60Km/h
Range: >50KM
Max Load: 100Kg
Weight: 23Kg
but upgraded to this
"Bafang M620 G510 unit , which has been upgraded with The X1 controller"?
Is this the controller?

Archon X1 Controller

Archon X1 Introducing a breakthrough in mid-drive motor technology. Watt Wagons launches the Archon X1 controller for the Bafang Ultra. Developed in Germany, the Archon X1 pushes the Bafang Ultra to a world beating performance standard. Upgrade Today! 2 Year WarrantyOn the controller only Up to...

wattwagons.com

Knowing what you have will help you figure out what you need to run it.

Note that the X1 page has conflicting information. It shows that it can supply twice the power than the built in controller but it says it has lower power draw and higher range, which are impossible to all have at the same time, so I don't trust anything it says on that page. Whoever wrote it probably either doesn't understand how things work and translated the actual information into marketing speak, or simply lied to gain sales, but it leaves none of the information useful/trustworthy.

Since it doesn't list it's actual current draw, then to know what battery you would need to support it , you would need to measure the actual current draw from your battery under your worst-case conditions.

Regarding Wh/mile, what range did you get from the original 14Ah battery on the X1 controller under your present riding conditions?

Alernately you can measure that based on watts used over time if you track that, or you can use a wattmeter or coulometer between battery and controller if the display of the system doesn't already track this info (which would be correct regardless of your actual battery capacity listing accuracy as it would all be measured in the controller/display system).

Such a device will also let you measure watts and amps and other data which will let you both know what to get to power it successfully and to troubleshoot problems later on when necessary.

 

[technotony007]

It is a version of my bike , but mine was sourced from Ali express , with better parts. As I found the Kirbebike Vapour to expensive to honest. So i sourced it myself. I sent my motor and had the X1 controller installed in Germany , by the guys at Innotrace.

I only seemed to get 10 to 15 miles out of the one batterys on average.

my current thoughts is going to built a 52v 24ah battery built with samsung 40t 21700 cells , with a 35 a bms.


am hoping to get better millage with this.

 

[technotony007]

I've just had Jimmy from ebikebatteries.co.uk build me a 52v pack using Samsung 50s cells for my cyc x1 Stealth which uses the x6 controller.

Thanks for that , i will give him a try. is he reasonable in costs, and are 18650 or 21700 ?

 

[E-HP]

my current thoughts is going to built a 52v 24ah battery built with samsung 40t 21700 cells , with a 35 a bms.

You can fit 70 cells of Samsung 50E's in that triangle, so that's 24.5Ah and 50A.

 

[seanchad]

He's not cheap but well recommend, speak to him about your needs and he will make a suggestion. I just asked him what he would suggest and came back with a quote. He does all his interconnects with copper.

Cost me £700 including charger and delivery

14s3p Samsung 50s, max continuous discharge 90a

 

[technotony007]

He's not cheap but well recommend, speak to him about your needs and he will make a suggestion. I just asked him what he would suggest and came back with a quote. He does all his interconnects with copper.

Cost me £700 including charger and delivery

14s3p Samsung 50s, max continuous discharge 90a

Thanks for the Tip , I will chat with him to see his opinion on the best option is.

 

[technotony007]

You can fit 70 cells of Samsung 50E's in that triangle, so that's 24.5Ah and 50A.

Thanks for that , that sounds like a good option too.

 

[technotony007]

wha

He's not cheap but well recommend, speak to him about your needs and he will make a suggestion. I just asked him what he would suggest and came back with a quote. He does all his interconnects with copper.

Cost me £700 including charger and delivery

14s3p Samsung 50s, max continuous discharge

what sort of range are you getting with that ?

 

[seanchad]

wha


what sort of range are you getting with that ?

Sorry I don't have enough time with it yet to give you a decent estimate plus it very much depends on too many factors for it to mean much to anyone else.

You could have a different motor, be half my size on a light weight bike living in a mostly flat area and with a different style of riding. I'm enjoying full unrestricted throttle too much at the minute!

 

[technotony007]

Been emailing a few UK battery builders , they have quoted :

£550 for 14s6p Samsung 21700 40t , 24AH

and

Samsung INR21700-50S cells to achieve 45Ah capacity and 270A of continuous discharge current - will come in at around £1,600.00

the second one , uses copper instead of nickle between the Cells

 

[greenno]

A buddy of mine has a Kirby “vapour”, in fact two friends of mine do.
They came with the standard battery which we removed and built a size specific pack to fit inside the main triangle and in fact is held in place with a moose trek m/t zippered bag. Works perfect.
They have the stock M620 motor limeted to 1500w, 30a max current.
They each have a 34ahr battery as well as a 24ahr battery in two separate bags which they swap out depending on the ride.

Another friend has the same bike as me an EXESS HP E180.
Both have the M620 motors as well as the Archon X1 controllers.
Mine is the standard 1500w, 30a max and his is the 2200w 50a version.
These also have the 34ahr and 24ahr packs as well fitting inside the main triangles.

I built all 4 of these 52v 30a/50a packs using Sanyo GA 18650 cells rated for 3.45ahr and 10a discharge.

Each cell group has a minimum of (10) series connections between them with each jumper rated at 7a per jumper.
Even with the full 30a draw only 3a max would be flowing across the cells and being rated at 10a they don’t suffer from any heating issues. Even maxing out the higher wattage unit only draws around 6a per cell so still have a bit of cushion.
All cell connections are spot welded with a Kweld unit and BMS wiring is done with #10 awg wiring ( tin coating ) and soldered directly to the nickel between the cells to limit any excessive heat transfer.
The charge wires are fitted with a XT60 female plug and the motor gets a XT90 female plug as well.

After all connections are completed and the BMS is plugged in the final testing is completed.
I then cut out heavy duty insulating paper to cover both sides of the battery and then wrap completely with 1/4” foam board using some gorilla tape to seal all openings.I then place the battery’s inside the bags and secure to the bike cutting a small hole along the bottom rear of the bag to route the motor plug up inside the bag where it’s then plugged into the battery. This keeps everything secure and safe

All battery’s are designed to fit comfortably inside the triangle area so as not to interfere with any shock movement or adjustment that’s needed.

IMO the 18650 cells work better for me instead of the 21700 cells as the nickel belt 4cross cell connections only come in the 18650 style.

Been making battery’s for about 3 years or so and being a retired electrical contractor I have the background to do this safely and efficientl.

Have not had ONE issue with these packs and have probably done 30 or so.

My water/backpack allready weighs in at around 16lbs with all the shite I carry on rides.
So carrying around another spare battery was never really an option.

You should have enough real estate inside your frame for a properly designed pack to handle your needs.

With the higher wattage motor your previous battery were probably only designed to carry 25-30 a max that’s why the BMS’s failed.
And then when you bypassed those and went directly to the pack you cooked them.
Those packs are made with lesser capacity cells and not the proper one’s needed.

To design a pack to work correctly takes a bit of thought if you want it to successful.

 

[scianiac]

After using a backpack battery for awhile and recently switching to a frame mounted battery I would say it's always worth the effort to figure out how to frame mount the battery. The suspension works so much better when it has more weight to work against and your own body suspension works so much better while being more comfortable. I have possibly one of the worst frame designs (Santa Cruz V10.3) to fit batteries on and I figured it out and it was totally worth it.

 

[technotony007]

A buddy of mine has a Kirby “vapour”, in fact two friends of mine do.
They came with the standard battery which we removed and built a size specific pack to fit inside the main triangle and in fact is held in place with a moose trek m/t zippered bag. Works perfect.
They have the stock M620 motor limeted to 1500w, 30a max current.
They each have a 34ahr battery as well as a 24ahr battery in two separate bags which they swap out depending on the ride.

Another friend has the same bike as me an EXESS HP E180.
Both have the M620 motors as well as the Archon X1 controllers.
Mine is the standard 1500w, 30a max and his is the 2200w 50a version.
These also have the 34ahr and 24ahr packs as well fitting inside the main triangles.

I built all 4 of these 52v 30a/50a packs using Sanyo GA 18650 cells rated for 3.45ahr and 10a discharge.

Each cell group has a minimum of (10) series connections between them with each jumper rated at 7a per jumper.
Even with the full 30a draw only 3a max would be flowing across the cells and being rated at 10a they don’t suffer from any heating issues. Even maxing out the higher wattage unit only draws around 6a per cell so still have a bit of cushion.
All cell connections are spot welded with a Kweld unit and BMS wiring is done with #10 awg wiring ( tin coating ) and soldered directly to the nickel between the cells to limit any excessive heat transfer.
The charge wires are fitted with a XT60 female plug and the motor gets a XT90 female plug as well.

After all connections are completed and the BMS is plugged in the final testing is completed.
I then cut out heavy duty insulating paper to cover both sides of the battery and then wrap completely with 1/4” foam board using some gorilla tape to seal all openings.I then place the battery’s inside the bags and secure to the bike cutting a small hole along the bottom rear of the bag to route the motor plug up inside the bag where it’s then plugged into the battery. This keeps everything secure and safe

All battery’s are designed to fit comfortably inside the triangle area so as not to interfere with any shock movement or adjustment that’s needed.

IMO the 18650 cells work better for me instead of the 21700 cells as the nickel belt 4cross cell connections only come in the 18650 style.

Been making battery’s for about 3 years or so and being a retired electrical contractor I have the background to do this safely and efficientl.

Have not had ONE issue with these packs and have probably done 30 or so.

My water/backpack allready weighs in at around 16lbs with all the shite I carry on rides.
So carrying around another spare battery was never really an option.

You should have enough real estate inside your frame for a properly designed pack to handle your needs.

With the higher wattage motor your previous battery were probably only designed to carry 25-30 a max that’s why the BMS’s failed.
And then when you bypassed those and went directly to the pack you cooked them.
Those packs are made with lesser capacity cells and not the proper one’s needed.

To design a pack to work correctly takes a bit of thought if you want it to successful.

Hi ,
would be interested in making my a battery , suitable for the spec on my bike ?

 

[greenno]

Send me a PM Im in San Diego.

 

[calab]

A different type of frame bag called Additive Bag V2

ADDITIVE BAG V2

Die Fahrradtasche V2 passt in jedes Rahmendreieck mit Oberrohr, auch für E-Bikes und Fullys geeignet!

www.additive-bikes.com

might be good for lego-set LIPO battery to spread out inside bag.