yet another solderless DIY battery pack via NIB's

Batteries, Chargers, and Battery Management Systems.
Post Reply
cwah   10 GW

10 GW
Posts: 4130
Joined: Jul 24 2011 5:42am
Location: Between paris and london

Re: yet another solderless DIY battery pack via NIB's

Post by cwah » Jan 03 2015 7:46am

Thanks thst's great.

Are you not using cells bracket anymore? How do you hold cells in place and make sure chaffing aren't going to create short over time?
Help me find my stolen electric brompton: http://bit.ly/1a0vbBC and Bosch Sinus B3 http://bit.ly/1eV0WQz

User avatar
TheBeastie   1 MW

1 MW
Posts: 1753
Joined: Jul 28 2012 12:31am
Location: Melbourne Australia

Re: yet another solderless DIY battery pack via NIB's

Post by TheBeastie » Jan 03 2015 8:37am

cwah wrote:Thanks thst's great.

Are you not using cells bracket anymore? How do you hold cells in place and make sure chaffing aren't going to create short over time?
Yeah I am using cell holder brackets, I re-uploaded the pics smaller so you dont have to click on them to see them, you can see them yeah?
The cell holder brackets that came with my battery case are significantly smaller, they seem to be deliberately designed to have less gap between each cell so you can pack in more cells in a small area, but I left some of them too close to the window and they got too hot and half are deformed/melted so I had to go back to using the most common 18650 cell holder which are quite spacey.
I haven't been able to find any one who sells the more compact 18650s holders except the guy who sold me the case and he wants $20 US just for a couple of cell holders to replace the ones I accidentally melted and deformed.
Speed Kills Range, 10mph = 46 miles range, 20mph = 20 miles, 30mph = 8 miles rangehttps://goo.gl/1JNL53
Over Charging Kills ur battery bit.ly/1hzWKl4
Consider PAS as your only throttle https://goo.gl/Kg1F8F
Fuel-Cell is the ultimate battery coupled with 4th-gen Nuclear
https://goo.gl/TcKtHs https://goo.gl/ZhFFot https://goo.gl/gfa215
10 Square Miles of solar panels = 0.12GW average power! https://goo.gl/Ub1S39

cwah   10 GW

10 GW
Posts: 4130
Joined: Jul 24 2011 5:42am
Location: Between paris and london

Re: yet another solderless DIY battery pack via NIB's

Post by cwah » Jan 03 2015 9:20am

Oh I just saw them.

Why did you use aluminium foil rather than nickel sheet?
http://www.ebay.co.uk/itm/Common-Nickel ... 35c6db75d3

I suppose nickel sheet should be enough? You could fold them like this guy for parallelling row of cells:
Image

Actually, your pack construction could be the same as this guy, but you would use magnet instead of compression strap to hold cells together
Help me find my stolen electric brompton: http://bit.ly/1a0vbBC and Bosch Sinus B3 http://bit.ly/1eV0WQz

cwah   10 GW

10 GW
Posts: 4130
Joined: Jul 24 2011 5:42am
Location: Between paris and london

Re: yet another solderless DIY battery pack via NIB's

Post by cwah » Jan 03 2015 9:24am

Again, looking at this guy, he is using properly the cells bracket and his bus bars fit just perfectly inside the bracket:
Image

It's much safer as he doesn't need to be afraid of the bus bar (in your case nickel sheet) moving around as it's contained inside the bracket "rail".
Help me find my stolen electric brompton: http://bit.ly/1a0vbBC and Bosch Sinus B3 http://bit.ly/1eV0WQz

User avatar
TheBeastie   1 MW

1 MW
Posts: 1753
Joined: Jul 28 2012 12:31am
Location: Melbourne Australia

Re: yet another solderless DIY battery pack via NIB's

Post by TheBeastie » Jan 05 2015 2:10am

Here is another update where i have used copper foil with one side having adhesive layer.
I placed the nibs in the middle and wrapped the copper foil over, using this copper foil has a few upsides, firstly when its wrapped up you have less chance of a nib jumping, nib jumping has only ever happened to me when trying to pull them off though.
Also because its now one piece you can take off a set in one quick go instead of having to take nibs off individually.

Went for one bike ride with it like that and so far it seems to work fine.

As for why I have done this or that as you can tell from my DIY workmanship vs some of the other guys I haven't really put in proper planing into the build and often when I do it still all ends up looking like this anyway.

After 3 weeks of solid work on fabricating my metal battery box this is what I ended up with until I gave up.
images.jpg
My Batterybox, JK!
images.jpg (6.89 KiB) Viewed 4493 times

I am interested in using copper foil or aluminium foil as both of my purchase sources offer it incredibly thin so it can easily contour/mold/shaped to the battery flat contact surface. If you go for a tougher thickness then it can be more up to luck that you get a good flat even contact. The nickle sheet I bought was pretty thin but not nearly as thin as the copper or aluminium foil.

Also you can see with the nickle piece right next to the end copper strip that I cut to shape with a stanley knife the the nickle sheeting that was protruding over the cell holder plastic parts that get in the way to help make a more uniform contouring fit. I might try make a proper stencil and make a more perfect cut sometime, which would resemble the parts like this but just be thinner. http://www.aliexpress.com/item/0-2mm-Pu ... 19821.html
Attachments
IMAG0221_1.jpg
IMAG0221_1.jpg (72.67 KiB) Viewed 4495 times
Speed Kills Range, 10mph = 46 miles range, 20mph = 20 miles, 30mph = 8 miles rangehttps://goo.gl/1JNL53
Over Charging Kills ur battery bit.ly/1hzWKl4
Consider PAS as your only throttle https://goo.gl/Kg1F8F
Fuel-Cell is the ultimate battery coupled with 4th-gen Nuclear
https://goo.gl/TcKtHs https://goo.gl/ZhFFot https://goo.gl/gfa215
10 Square Miles of solar panels = 0.12GW average power! https://goo.gl/Ub1S39

cwah   10 GW

10 GW
Posts: 4130
Joined: Jul 24 2011 5:42am
Location: Between paris and london

Re: yet another solderless DIY battery pack via NIB's

Post by cwah » Jan 05 2015 6:42pm

Hey that looks much better like this. It has better use of the cell brackets design.

Are you using these 12x2mm N50 magnets?
http://www.ebay.com/itm/Disc-10pcs-12mm ... 1e97b5d2dc

Would these be secure enough?
Help me find my stolen electric brompton: http://bit.ly/1a0vbBC and Bosch Sinus B3 http://bit.ly/1eV0WQz

User avatar
TheBeastie   1 MW

1 MW
Posts: 1753
Joined: Jul 28 2012 12:31am
Location: Melbourne Australia

Re: yet another solderless DIY battery pack via NIB's

Post by TheBeastie » Jan 06 2015 12:10am

cwah wrote:Hey that looks much better like this. It has better use of the cell brackets design.

Are you using these 12x2mm N50 magnets?
http://www.ebay.com/itm/Disc-10pcs-12mm ... 1e97b5d2dc

Would these be secure enough?
I have ended up with all sorts of sizes now as my design has changed.
12x2mm are the best all rounder size if your not sure if you want pure contact or not.
In the copper wrap I am using 12mmx3mm that extra mil seems to give good magnetic strength.
If I was going for a design with just pure 1 nib per contact where the foil touches battery contact first I think I still prefer 12x3mm, I am thinking 12x2.5mm might be the best middle ground between good strength and not excess weight or chunkyness.

But 12mm is only really good for the negative terminal, I am going 10mmx2mm for a lot of the postitive terminals, 12mm seems too wide and you can feel the magnetic strength pulling from other magnets because it can't attach it self to the full contact battery surface because its the smaller positive terminal so 10mm (maybe even 9mm) is much better for positive.
Speed Kills Range, 10mph = 46 miles range, 20mph = 20 miles, 30mph = 8 miles rangehttps://goo.gl/1JNL53
Over Charging Kills ur battery bit.ly/1hzWKl4
Consider PAS as your only throttle https://goo.gl/Kg1F8F
Fuel-Cell is the ultimate battery coupled with 4th-gen Nuclear
https://goo.gl/TcKtHs https://goo.gl/ZhFFot https://goo.gl/gfa215
10 Square Miles of solar panels = 0.12GW average power! https://goo.gl/Ub1S39

cwah   10 GW

10 GW
Posts: 4130
Joined: Jul 24 2011 5:42am
Location: Between paris and london

Re: yet another solderless DIY battery pack via NIB's

Post by cwah » Jan 06 2015 7:47am

Wouldn't that be better to have the same size for both? Maybe 9mm wide and 3mm thick on all?

After all, it needs the same magnet strength whether its positive or negative terminal
Help me find my stolen electric brompton: http://bit.ly/1a0vbBC and Bosch Sinus B3 http://bit.ly/1eV0WQz

wiredsim   1 W

1 W
Posts: 51
Joined: Nov 02 2008 5:05pm
Location: Holland, MI

Re: yet another solderless DIY battery pack via NIB's

Post by wiredsim » Jan 07 2015 10:35am

The problem with the smaller magnets for me is it pulls towards the side of the cell when on the positive terminal, the draw towards the side of the cell is higher then the downward forward towards the smaller positive terminal? Anyway what seems to be ideal is a magnet that just fits into the bracket and that doesn't allow it much lateral movement. I have similar copper foil, but it's narrower, just wide enough to fit between the bracket edges, it's extremely thin and is adhesive backed, I'm thinking of using that with real N50 12mm cells to see what kind of resistance it offers, I like how you have it wrapped over the cells however. I've only used the copper foil for charging as of yet.

I found that the nickel sheets I purchased that were pre-formed were just too thick. I also found that my brackets warp considerably and that is enough of a problem that I am using those brackets for a Snath like pressure pack rather then NIB's. I suspect the 3x1's or larger would be better then the 2x1's I purchased.

User avatar
TheBeastie   1 MW

1 MW
Posts: 1753
Joined: Jul 28 2012 12:31am
Location: Melbourne Australia

Re: yet another solderless DIY battery pack via NIB's

Post by TheBeastie » Jan 08 2015 7:17am

wiredsim wrote:
I found that the nickel sheets I purchased that were pre-formed were just too thick
OK cool, yeah there was a demon inside me that wanted to buy and try those, now my demon is happy to see it would of been a failure, or maybe your failure :twisted: .
I kept looking at those pre-formed cuts and worried they would be too thick or just some how not fit, also all the holes and openings in them weren't ideal for maximum metal contact with nibs, all up I just felt it was too catered to spot welds and wouldn't be worth it now I got so many other choices.
Speed Kills Range, 10mph = 46 miles range, 20mph = 20 miles, 30mph = 8 miles rangehttps://goo.gl/1JNL53
Over Charging Kills ur battery bit.ly/1hzWKl4
Consider PAS as your only throttle https://goo.gl/Kg1F8F
Fuel-Cell is the ultimate battery coupled with 4th-gen Nuclear
https://goo.gl/TcKtHs https://goo.gl/ZhFFot https://goo.gl/gfa215
10 Square Miles of solar panels = 0.12GW average power! https://goo.gl/Ub1S39

User avatar
TheBeastie   1 MW

1 MW
Posts: 1753
Joined: Jul 28 2012 12:31am
Location: Melbourne Australia

Re: yet another solderless DIY battery pack via NIB's

Post by TheBeastie » Jan 17 2015 3:47pm

I have got my nib pack up in running in the plastic bike case that I bought.
It looks a lot better now then what I had the triangle frame bag.

I kind of cut a hole and placed a removable LCD display that shows individual cell voltages, I still might remake it into a nicer one but it looks kind of funky.

To fit the nib pack in the case I had to use just one 12x3mm on each negative terminal, anything more and it wouldn't fit in the case (like having 2 nibs per connection) its mostly copper foil with a few being aluminium foil (about 8 layers per connection) as I ran out of copper foil.

I discarded the cell holders that came with the case as they easily deformed from any kind of heat like my hot glue gun more on this issue on this thread here... http://www.endless-sphere.com/forums/vi ... 71#p993064
As shown in that specific post I decided to use rubber tubing as my cell holders this way I have less obstacles in the way of each connection as terminal nib connection 'contour' was a big issue with my pack.

I am happy with the performance but who knows maybe in the future I might go back to direct nickle connections if I graph out my cell voltage data over time and don't like what I see on my current setup. As I have said contour with the terminals has somewhat caused me to run in circles when testing with different materials.

Anyway here is a few photos and a vid of my pack on the bike.


Its kind of themed like the X-Files Season 2 Episode 3 "Blood", watch the first 5 minutes to understand.. :) http://www.dailymotion.com/video/x2688q ... 3-blood_tv
Attachments
01fa7d378be4904864a67fca2922728206277da260.jpg
01fa7d378be4904864a67fca2922728206277da260.jpg (203.73 KiB) Viewed 4280 times
Last edited by TheBeastie on Jan 20 2015 12:27pm, edited 1 time in total.
Speed Kills Range, 10mph = 46 miles range, 20mph = 20 miles, 30mph = 8 miles rangehttps://goo.gl/1JNL53
Over Charging Kills ur battery bit.ly/1hzWKl4
Consider PAS as your only throttle https://goo.gl/Kg1F8F
Fuel-Cell is the ultimate battery coupled with 4th-gen Nuclear
https://goo.gl/TcKtHs https://goo.gl/ZhFFot https://goo.gl/gfa215
10 Square Miles of solar panels = 0.12GW average power! https://goo.gl/Ub1S39

davidcandlelight   1 µW

1 µW
Posts: 2
Joined: Jan 13 2015 5:38am

Re: yet another solderless DIY battery pack via NIB's

Post by davidcandlelight » Jan 17 2015 11:54pm

I originally thought of building my solder-less pack with magnets, however, I went with springs.
I'd like to build a new one using magnets and then upgrade the older one to use them as well.
Which magnets do you recommend? I found this company near my home.
http://www.allmagnet.com/NdFeB-Magnet.html?CID=1

Are these NdFeB Magnet a good choice?
How big and thick should they be on the negative pole and how big on the positive one.
I am thinking of making them on the negative side bigger and flatter and on the positive side much smaller and thicker/stronger.

Also, I will put a thin copper sheet in between to make the contact. It will be narrowed somewhere at the positive side to form a simple fuse for each cell.
Has anyone experimented with such fuses before?
How thick should the copper sheet be and how narrow do I have to make it to burn out to protect the cell.
I could figure it out by try and error using a resistor and short-cutting one old cell.

What resistor should I use and after how many seconds should the connection burn out/fail?

Any suggestions thanks!

User avatar
hagerty1   100 mW

100 mW
Posts: 35
Joined: Nov 04 2014 6:12am

Re: yet another solderless DIY battery pack via NIB's

Post by hagerty1 » Jan 19 2015 7:43am

davidcandlelight wrote:I originally thought of building my solder-less pack with magnets, however, I went with springs.
I'd like to build a new one using magnets and then upgrade the older one to use them as well.
Which magnets do you recommend? I found this company near my home.
http://www.allmagnet.com/NdFeB-Magnet.html?CID=1

Are these NdFeB Magnet a good choice?
How big and thick should they be on the negative pole and how big on the positive one.
I am thinking of making them on the negative side bigger and flatter and on the positive side much smaller and thicker/stronger.

Also, I will put a thin copper sheet in between to make the contact. It will be narrowed somewhere at the positive side to form a simple fuse for each cell.
Has anyone experimented with such fuses before?
How thick should the copper sheet be and how narrow do I have to make it to burn out to protect the cell.
I could figure it out by try and error using a resistor and short-cutting one old cell.

What resistor should I use and after how many seconds should the connection burn out/fail?

Any suggestions thanks!
I have a good stock of very high power N-52 10 mm x 3 mm Neodymium, you won't find many available
P.M. if interested.
Rolliing Sytems since 1992
Since light travels faster than sound,
some people appear bright until you hear them speak.

User avatar
TheBeastie   1 MW

1 MW
Posts: 1753
Joined: Jul 28 2012 12:31am
Location: Melbourne Australia

Re: yet another solderless DIY battery pack via NIB's

Post by TheBeastie » Jan 25 2015 1:59pm

Here is an update to my 18650 nib pack.

I wired inside of my pack this wireless vibration activation alarm from fasttech.com

http://www.fasttech.com/products/0/1001 ... t-security
sku_352892_1.jpg
sku_352892_1.jpg (20.37 KiB) Viewed 4140 times
My pack, I pulled off the original casing the bits that matter inside are comparatively tiny.
Here is a video testing it wired into the opened battery pack. I hesitated on deliberately vibrating it as the alarm is really loud and its late at night atm.

Attachments
IMAG02244.jpg
IMAG02244.jpg (180.68 KiB) Viewed 4140 times
Speed Kills Range, 10mph = 46 miles range, 20mph = 20 miles, 30mph = 8 miles rangehttps://goo.gl/1JNL53
Over Charging Kills ur battery bit.ly/1hzWKl4
Consider PAS as your only throttle https://goo.gl/Kg1F8F
Fuel-Cell is the ultimate battery coupled with 4th-gen Nuclear
https://goo.gl/TcKtHs https://goo.gl/ZhFFot https://goo.gl/gfa215
10 Square Miles of solar panels = 0.12GW average power! https://goo.gl/Ub1S39

cwah   10 GW

10 GW
Posts: 4130
Joined: Jul 24 2011 5:42am
Location: Between paris and london

Re: yet another solderless DIY battery pack via NIB's

Post by cwah » Jan 25 2015 3:27pm

what is the gold stuff on top of the cells, and why are you adding that? Isn't the nickel sheet below already good enough?
Help me find my stolen electric brompton: http://bit.ly/1a0vbBC and Bosch Sinus B3 http://bit.ly/1eV0WQz

User avatar
TheBeastie   1 MW

1 MW
Posts: 1753
Joined: Jul 28 2012 12:31am
Location: Melbourne Australia

Re: yet another solderless DIY battery pack via NIB's

Post by TheBeastie » Jan 26 2015 7:37am

cwah wrote:what is the gold stuff on top of the cells, and why are you adding that? Isn't the nickel sheet below already good enough?
Mainly because the nickel I have at least had my hands on is stiffer and causes poor "contour" to the battery terminal points, or that at the same time I was using crap cell holders that got in the way, can't be bothered retesting.. Refer back to x-speed posts for the most technical point of view.
The copper foil I had was just sitting around and its very thin and contouring to the battery surface points.
It could be now that I have fully got rid of my cell holders the problems I have had with nickel sheets might of full gone away as the cell holders made it much more difficult to get good contour. I just haven't gone back to it because I am kind of interested in trying them all and at least what I have atm works well.

The nickel sheet I ordered from ebay was pretty thin as far as specifications go but the same thinness copper contours a lot more easily.

Here it is in the triangle frame. As you can see this battery box could be twice as big and fit just fine in my Trek DS 8.4 bike. I think its annoying they made the box so small, I think if it was a tad bigger for say 5P or even 6P it would be perfect. I can only assume it was designed for people who bought extremely small bike triangle frames.
I am more happy with it then my triangle frame bag from EM3, I can take my battery off more easily now then a frame bag believe it or not..
One of the reasons I have moved away from frame bag was the fact that from at least personal experience it draws more eyes looking at your bike if they can't see through the frame (I don't want to draw attention).
Attachments
IMAG02311.jpg
IMAG02311.jpg (104.3 KiB) Viewed 4116 times
Last edited by TheBeastie on Jun 07 2015 5:52am, edited 4 times in total.
Speed Kills Range, 10mph = 46 miles range, 20mph = 20 miles, 30mph = 8 miles rangehttps://goo.gl/1JNL53
Over Charging Kills ur battery bit.ly/1hzWKl4
Consider PAS as your only throttle https://goo.gl/Kg1F8F
Fuel-Cell is the ultimate battery coupled with 4th-gen Nuclear
https://goo.gl/TcKtHs https://goo.gl/ZhFFot https://goo.gl/gfa215
10 Square Miles of solar panels = 0.12GW average power! https://goo.gl/Ub1S39

cwah   10 GW

10 GW
Posts: 4130
Joined: Jul 24 2011 5:42am
Location: Between paris and london

Re: yet another solderless DIY battery pack via NIB's

Post by cwah » Feb 03 2015 8:22pm

Yes I'm mostly using these bottle battery but I'd have hoped to someday find one that can hold 100 cells!

I'm about to buy these magnet I'd use for both side:
http://www.ebay.co.uk/itm/50-100-200x-N ... 1e98a281c3

Any other advice before I hit the buy button?
Help me find my stolen electric brompton: http://bit.ly/1a0vbBC and Bosch Sinus B3 http://bit.ly/1eV0WQz

User avatar
TheBeastie   1 MW

1 MW
Posts: 1753
Joined: Jul 28 2012 12:31am
Location: Melbourne Australia

Re: yet another solderless DIY battery pack via NIB's

Post by TheBeastie » Feb 03 2015 9:12pm

cwah wrote:Yes I'm mostly using these bottle battery but I'd have hoped to someday find one that can hold 100 cells!

I'm about to buy these magnet I'd use for both side:
http://www.ebay.co.uk/itm/50-100-200x-N ... 1e98a281c3

Any other advice before I hit the buy button?
Depends on how your going to build it, if your going for direct contact of the sheet metal only as in only 1 nib per contact then I recommend 12mmx3mm. But alternately with 2mm if you don't like 2mm you can just double them together for 4mm and get the same effect.

I got a lot of spare nibs on my fridge now as my designed turned full circle, and I ended up with only 12mmx3mm on all negative terminals only and have all the 12mmx2mm sitting around.
Speed Kills Range, 10mph = 46 miles range, 20mph = 20 miles, 30mph = 8 miles rangehttps://goo.gl/1JNL53
Over Charging Kills ur battery bit.ly/1hzWKl4
Consider PAS as your only throttle https://goo.gl/Kg1F8F
Fuel-Cell is the ultimate battery coupled with 4th-gen Nuclear
https://goo.gl/TcKtHs https://goo.gl/ZhFFot https://goo.gl/gfa215
10 Square Miles of solar panels = 0.12GW average power! https://goo.gl/Ub1S39

User avatar
hagerty1   100 mW

100 mW
Posts: 35
Joined: Nov 04 2014 6:12am

Re: yet another solderless DIY battery pack via NIB's

Post by hagerty1 » Feb 04 2015 3:59pm

Watch your stack thickness if you buy 2 mm thick magnets and use cell holders. I have found that 3 mm thickness
is min for good stack. They are out there on E-Bay at a good price. 12 mm x 3 mm N-52 I just bought a few hundred with counter bore holes for another mount method they were around 14 cents U.S.
cwah wrote:Yes I'm mostly using these bottle battery but I'd have hoped to someday find one that can hold 100 cells!

I'm about to buy these magnet I'd use for both side:
http://www.ebay.co.uk/itm/50-100-200x-N ... 1e98a281c3

Any other advice before I hit the buy button?
Rolliing Sytems since 1992
Since light travels faster than sound,
some people appear bright until you hear them speak.

cwah   10 GW

10 GW
Posts: 4130
Joined: Jul 24 2011 5:42am
Location: Between paris and london

Re: yet another solderless DIY battery pack via NIB's

Post by cwah » Feb 04 2015 4:31pm

can you give good price link?

I was thinking 10mmx3mm
Help me find my stolen electric brompton: http://bit.ly/1a0vbBC and Bosch Sinus B3 http://bit.ly/1eV0WQz

rtz   1 mW

1 mW
Posts: 14
Joined: Nov 25 2013 12:32am
Location: Edmond, OK

Re: yet another solderless DIY battery pack via NIB's

Post by rtz » Feb 04 2015 7:15pm

Another source for powerful magnets. Some huge ones if need be for experimenting: http://unitednuclear.com/index.php?main ... Path=70_71

User avatar
hagerty1   100 mW

100 mW
Posts: 35
Joined: Nov 04 2014 6:12am

Re: yet another solderless DIY battery pack via NIB's

Post by hagerty1 » Feb 05 2015 8:10am

http://www.ebay.com/itm/50pcs-N50-Stron ... 2518.l4276 These are around 17 cents N50. 10 mm x 3 mm free ship

Or P.M. me one more time and I will try to hook you up with some of mine.
cwah wrote:can you give good price link?

I was thinking 10mmx3mm
Rolliing Sytems since 1992
Since light travels faster than sound,
some people appear bright until you hear them speak.

cwah   10 GW

10 GW
Posts: 4130
Joined: Jul 24 2011 5:42am
Location: Between paris and london

Re: yet another solderless DIY battery pack via NIB's

Post by cwah » Feb 05 2015 8:35am

Thanks but with a whole it's less strong than without hole I suppose?
Help me find my stolen electric brompton: http://bit.ly/1a0vbBC and Bosch Sinus B3 http://bit.ly/1eV0WQz

User avatar
hagerty1   100 mW

100 mW
Posts: 35
Joined: Nov 04 2014 6:12am

Re: yet another solderless DIY battery pack via NIB's

Post by hagerty1 » Feb 06 2015 1:04pm

No the pull force is almost identical. The hole just changes the flux of the field. Besides I'm sure you already know that you are WAY below what is known as saturation using a 10 mm x 3 mm N-50 or above so any additional grip is lost anyhow as the thickness of the metal can of the cell and the anode end assembly are far less than the minimum thickness of metal required to hit full saturation of these N-50+ Neo Mags.
cwah wrote:Thanks but with a whole it's less strong than without hole I suppose?
Rolliing Sytems since 1992
Since light travels faster than sound,
some people appear bright until you hear them speak.

cwah   10 GW

10 GW
Posts: 4130
Joined: Jul 24 2011 5:42am
Location: Between paris and london

Re: yet another solderless DIY battery pack via NIB's

Post by cwah » Feb 07 2015 9:28am

thanks I'm going to buy these magnets then
Help me find my stolen electric brompton: http://bit.ly/1a0vbBC and Bosch Sinus B3 http://bit.ly/1eV0WQz

Post Reply