Nice dogman... giving me some ideas there. What about a thin, dense strong plywood? Trying to keep weight down, but am also envisioning a stained/varnished wood pack all of a sudden... not exactly stealthy, but sure would look pretty! :lol:
18650 battery holder
- Thread starter leamcorp
- Start date
MitchJi
10 MW
Hi,
I don't think plywood will work. My father spent several hours once (he was a skilled woodworker) trying to cut dovetail joints with a router in plywood. Talk about splintering :lol:
I think you could use similar tools, use thinner material and get much better results with some kind of plastic (cover it with stained/varnished wood if you want).
If someone comes up with a design that has wide appeal I bet we could have a bunch made affordably.
pwbset said:
I don't think plywood will work. My father spent several hours once (he was a skilled woodworker) trying to cut dovetail joints with a router in plywood. Talk about splintering :lol:
I think you could use similar tools, use thinner material and get much better results with some kind of plastic (cover it with stained/varnished wood if you want).
If someone comes up with a design that has wide appeal I bet we could have a bunch made affordably.
dogman dan
1 PW
Poplar wood would be the best for light weight, no spinters, and strength where it's thin, 3/4 thick stock should work, I just used a 1.5 inch pine because I knew I would be drilling fast and inaccurate. Just knocking out something better than a scrawled sketch to see how it might work. Some kind of plastic lumber should work fine too. The nice thing about wood, or similar material is the ease of working with it, ability to put in a screw wherever needed , etc. You don't need to get a big manufacturer to make em for you. Router templates could be passed around cheap. If spring clips could be found or made that could go on something 1/4 inch thick, I think you could use them. Maybe you could even sandwich a piece of metal between two wood or plastic sheets and clip to the metal, getting an automatic paralell connection? I guess that would get heavy though.
Excellent job.
I never had a 123 cell, how big are they compare to (C or D)? I imagine they are much bigger than 18650 cell.
I'll be making a mold in silicone on Monday. Probably 4 lathed 18650 cell size aluminum rods thats bit longer for clip/spring. Since 18650 is fairly close to A battery, multi-cell holder would be better???
For A123, if they are much bigger, then its probably better with 1 or 2 cell block??? since bulk/space requirement isn't as critical as 18650 since you only need so many for a typical pack.
As for what to do with clip/spring. I've been playing with the spring and I don't think its a big problem to insert each screw into the spring. I've use #2 machine screw and it went right in. The trick is to use a #2 wide washer as screw is inserted (mid point) so that it doesn't come out at opposite end.. Its still time consuming task but not too bad for larger cells.
I never had a 123 cell, how big are they compare to (C or D)? I imagine they are much bigger than 18650 cell.
I'll be making a mold in silicone on Monday. Probably 4 lathed 18650 cell size aluminum rods thats bit longer for clip/spring. Since 18650 is fairly close to A battery, multi-cell holder would be better???
For A123, if they are much bigger, then its probably better with 1 or 2 cell block??? since bulk/space requirement isn't as critical as 18650 since you only need so many for a typical pack.
As for what to do with clip/spring. I've been playing with the spring and I don't think its a big problem to insert each screw into the spring. I've use #2 machine screw and it went right in. The trick is to use a #2 wide washer as screw is inserted (mid point) so that it doesn't come out at opposite end.. Its still time consuming task but not too bad for larger cells.
liveforphysics
100 TW
I have lots of flashlight experience with ultrafire Li-Ion "2400mAh" 18650 batteries (actually measure between 1700-2000, yes, 15% variation in capacity). I'm actually sitting next to a box with about 20 of them in it. They are only good for about 1-1.5c sustained draw, and they have so much internal resistance that a lot of the battery energy is wasted if you plan to do more than just trickle power from them. I would strongly consider using other types of cells for an E-bike application, unless you are just looking for a few hundred watt system.
marty
10 MW
Turboferret 18650 Battery Holders
http://www.turboferret.co.uk/Index.shtm
http://www.turboferret.co.uk/Index.shtm
Here's the datasheet for the M1 cells:
http://a123systems.textdriven.com/product/pdf/1/ANR26650M1_Datasheet_AUGUST_2008.pdf
http://a123systems.textdriven.com/product/pdf/1/ANR26650M1_Datasheet_AUGUST_2008.pdf
slayer
1 kW
hi guys,
here is where i am at in my builds i took the springs from the a 123 and reversed them to be able to use a pop rivet for 2 spring takes less than a minutes to do the 6 that are on top of the pack... i have 1 quarter inch 20 threads per inch rods makes it very solid and put them side by side in 12 volts or 24 volts each side of the bike so that way i can alternate in summer and winter for easy 12 volts 46 ah or 48 volts 11.6 ah ...i will be cutting the rods to proper size and add the wiring for balancing.
i dont know how to add a pic so i try with upload attachmentView attachment PICT0015a.JPG
here is where i am at in my builds i took the springs from the a 123 and reversed them to be able to use a pop rivet for 2 spring takes less than a minutes to do the 6 that are on top of the pack... i have 1 quarter inch 20 threads per inch rods makes it very solid and put them side by side in 12 volts or 24 volts each side of the bike so that way i can alternate in summer and winter for easy 12 volts 46 ah or 48 volts 11.6 ah ...i will be cutting the rods to proper size and add the wiring for balancing.
i dont know how to add a pic so i try with upload attachmentView attachment PICT0015a.JPG
slayer
1 kW
Oh and if you need some spent a123 i have a couple of them
MitchJi
10 MW
Hi,
If someone has a spare you might want to request a Dewalt Cell end plate or two. Maybe you could modify it one for easier spring attachment or clip attachment and use it for a mold.
I think for A123 the ideal would be to have a choice of 1, 2 and 4 cell holders. If that's too many I'd vote for 2 and 4.
Self-tapping screws might work with clips.
Is it possible to use clips to hold the springs?
Pop rivets are a great idea
What are they pop riveted to?
Copper plumbers tape?
Do you mind posting a closeup?
leamcorp said:
If someone has a spare you might want to request a Dewalt Cell end plate or two. Maybe you could modify it one for easier spring attachment or clip attachment and use it for a mold.
I think for A123 the ideal would be to have a choice of 1, 2 and 4 cell holders. If that's too many I'd vote for 2 and 4.
Self-tapping screws might work with clips.
Is it possible to use clips to hold the springs?
slayer said:
Pop rivets are a great idea
What are they pop riveted to?
Copper plumbers tape?
Do you mind posting a closeup?
slayer
1 kW
yes it copper tape from canadian tire , oups my phone camera is not so good for close up i hope this helps
slayer
1 kW
liveforphysics said:
I'm not sure what brand of battery is in Mr.Lau's battery (can't imagine he'll use good battery) but I had a good luck with 18650 packs. I don't usually pedal first and it typically draw 30-35amps. Might not be A123 but can't beat the cost factor
Pwbset pointed me to TurboFerret's thread and while its a same idea - different application. I want a massive numbers of 18650 (about 120 for 48v 20ah).
Here's another holder I did for a proof of concept. I think I'm going to go in this direction for 18650 and probably individual or dual block style for A123.
While this one only holds 2 (ran out of aluminum stock) I'm thinking 4 or 8 cells at a time with snap on dowels would make a good design. With this design, the batteries will be protected via adjoining block and the last block will have a face plate to complete the pack. Neat self contained pack - all you need to do is to put it in a bag/case.
Here's another holder I did for a proof of concept. I think I'm going to go in this direction for 18650 and probably individual or dual block style for A123.
While this one only holds 2 (ran out of aluminum stock) I'm thinking 4 or 8 cells at a time with snap on dowels would make a good design. With this design, the batteries will be protected via adjoining block and the last block will have a face plate to complete the pack. Neat self contained pack - all you need to do is to put it in a bag/case.
Attachments
marty
10 MW
Just a idea. A123 26650 batteries are 26mm x 65mm. Don't know what the 0 is?
Look at http://en.wikipedia.org/wiki/Battery_(electricity) See C cell batteries are 26mm x 50mm.
Buy C cell battery holder and modify by making it longer or shorter to accept A123 26650 batteries. Think that black plastic could be glued with glue for that type of plastic. Don't know what type of plastic it is?
Lots of C cell holders here http://www.batteryholders.com/C_cellholders.shtml
Also I know it is fun to build stuff but please stop trying to build your own 18650 battery holders. This guy got it all done http://www.turboferret.co.uk/Index.shtm Look like he is all set up to sell and ship. He take PayPal. At least buy one and take a good look at how he do. Copy? Improve?
Look at http://en.wikipedia.org/wiki/Battery_(electricity) See C cell batteries are 26mm x 50mm.
Buy C cell battery holder and modify by making it longer or shorter to accept A123 26650 batteries. Think that black plastic could be glued with glue for that type of plastic. Don't know what type of plastic it is?
Lots of C cell holders here http://www.batteryholders.com/C_cellholders.shtml
Also I know it is fun to build stuff but please stop trying to build your own 18650 battery holders. This guy got it all done http://www.turboferret.co.uk/Index.shtm Look like he is all set up to sell and ship. He take PayPal. At least buy one and take a good look at how he do. Copy? Improve?
marty said:
All due respect I completely disagree with that statement. Turboferret's holders were meant for flashlights originally... not ebikes. His solution absolutely would not work for my needs and many here I think. It is an excellent solution, but I'm looking for a very large parallel 18650 holder not a 4s1p. 1s10p is my target.
marty
10 MW
pwbset said:
I am not a expert in electricity, parallel, series. Copy from http://www.turboferret.co.uk/4holder.php
Available in a variety of configurations depending on voltage requirements -
4S1P (4 cells in series) nominal pack voltage 14.4V £12
2S2P (2 pairs of cells in series in parallel) nominal pack voltage 7.2V £12
1S4P (4 cells in parallel) nominal pack voltage 3.7V £12
Sold with short flying leads to connect your own cables
Bare no wires, simply battery clips to solder as you wish £10.50
Couldn't you string a bunch of these together to do what you want?
marty said:
Marty, with all due respect and direction I didn't want to take.
Why? What is the point of your statement? I would like to know.
I think Turboferret's holder is great but it will not fit my requirement and most likely all other EV application.
This is an DIY hobby and thats part of the fun - to create something and contributing with each individual's unique ability. Ok, my first motivation was to save money but what I say still apply.
Also, Never mind the fact that it will not satisfy my "physical" requirement, the cost wise at today's conversion rate (1 British pound per US 1.44 dollar), i would have to pay $11.49 per Turbo's single holder. That would be $1378.80 for 120 holders. Thats without the cheap 18650 batteries, which was the sole reason why I wanted to make these.
Again, I'm not trying to break into this market (not enough money even if I wanted to), and if turbo needs help with casting/mass production, I would certainly help. But to make the quantity needed for EV application using gravity pour casting is not even economically possible - even at hobby level.
Again, there's no offense applied.
marty said:
You totally could yeah, but like leamcorp says it would be prohibitively expensive. I think that's going to be the crux of any "home made" solution is the sheer cost. Using 100s of 18650s with custom connectors really only makes sense for a one-off custom pack unless a major manufacturer gets involved. I'm back to thinking that copper strapping and a couple hundred springs is going to be the only way to go. It's really too bad that we can't get our hands on the konion 26650s or an even larger format konion like headway/PSI then we could just be dealing with the "legos" etc... problem solved. 18650s are a goofy size for ebike applications no doubt. Too bad these konions are such cool cells!
I think I'm getting close to a final version. Here's the latest,
This is 4 cell version but I'm going to make the 8 cell version also. The cell spacing is bit wide, so to save more space, I'm going to close the gap. Then I'll work on the actual holder dimension to make it small as possible. I want to make this so that it could be attached back to back and/or side to side.
One thing good about this design is that metal strip holding the clips can be used for soldering or to loop copper wiring so that you don't even have to solder (just need some hole). I think this design could also work for A123 or any other battery as well. But because of the size, I'll probably go with 2 cell size for those.
This is 4 cell version but I'm going to make the 8 cell version also. The cell spacing is bit wide, so to save more space, I'm going to close the gap. Then I'll work on the actual holder dimension to make it small as possible. I want to make this so that it could be attached back to back and/or side to side.
One thing good about this design is that metal strip holding the clips can be used for soldering or to loop copper wiring so that you don't even have to solder (just need some hole). I think this design could also work for A123 or any other battery as well. But because of the size, I'll probably go with 2 cell size for those.
Attachments
pwbset said:
Both side will look like tabbed side. I was trying different configurations. I'm trying to make serial/parallel configuration easy - so those metal strip could be metal or plastic.
Question, the way it is setup on the picture - parallel, right?
in order to do a serial connection - will reversing the battery orientation make it a serial where both + and - is touching the same metal strip? or do I have to make it so that its in chain configuration.
MitchJi
10 MW
Hi,
I think you should have the Cells connected in the holders in parallel and then connect the parallel sets of holders serially.
The whole point to holders is to be able to connect cells in parallel. If you want to connect individual cells serially (which doesn't work very well for Lithium) its very easy to do using tubes (like flashlights). No necessity to build custom holders.
Someone built a KMX trike with Lithium cells connected in serial groups in tubes and connected the tubes in parallel and the serial connection in the tubes worked well but that configuration didn't work well.
leamcorp said:
I think you should have the Cells connected in the holders in parallel and then connect the parallel sets of holders serially.
The whole point to holders is to be able to connect cells in parallel. If you want to connect individual cells serially (which doesn't work very well for Lithium) its very easy to do using tubes (like flashlights). No necessity to build custom holders.
Someone built a KMX trike with Lithium cells connected in serial groups in tubes and connected the tubes in parallel and the serial connection in the tubes worked well but that configuration didn't work well.
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