options for powering board with 18650 cells.

[delta_19]

so i want to make a 18650 battery pack for my board because lipo pouches are evil, EVIL!!

so far i have two plans

plan 1: make a battery pack with or with out a bms and run that charging with a hobby charger if i go bms-less or laptop charger if i get a bms.

plan 2: buy 6 of these https://www.fasttech.com/products/1009/10002233/1290003, upgrade the wiring to 10AWG and then i can pop out each cell in groups of 4 and throw them in a nitecore d4/i4 for charging.

plan 2 would take longer to charge but i could pop out any cell at any moment and make sure its healthy and happy.

 

[Grizzl-E]

Assuming your board pulls a typical amperage, those little cell holders will melt within a couple miles. The springs and internal connections are usually ~ 28 gauge equivalent. No way your powering an eboard on those.

 

[delta_19]

would something like this work, https://www.fasttech.com/products/1009/10002233/1290005

ot is there just nothing on the market for this much current?

 

[dirtbikr]

Hi!

I am actually creating what you are looking for right now. I wanted to easily be able to pop cells in and out if needed so I didn't have to disassemble an entire pack if one went south (I am building a 14S7P battery backpack for an AFT ebike kit). I have designed a bus bar out of 14AWG copper wiring with seven springs soldered to it (that I wound using a drill). My friend is almost finished with designing the holder, then we are going to print it out (3D printer). I am planning on putting the batteries in the holder and using zip ties to hold the two sides together, then stitch these 7P packs into a camelback. I will post pictures of what I have so far when I get home from work. I have to make another ~190 springs, so I could show you my method and the outcome and you can decide from there. I don't know if you have access to a 3D printer, but it makes the whole battery holder idea much more feasible.

Eric

 

[delta_19]

Ok I talked to a friend that vapes and he suggested that I just buy some vape 18650 sleds, there made for vapes that draw 20A so with the air running over them it should be no problem.


http://www.brimstonevapeco.com/product-p/slim-dual-18650.htm

this should have no problem, its made for sub-ohm dripper builds, and drippers get hawt.

 

[Grizzl-E]

What voltage and amperage are you running or planning to run?

 

[delta_19]

What voltage and amperage are you running or planning to run?

22.2 and 60A or less seeing as how that's the most the vesc can pull.

 

[Grizzl-E]

So minimum 3 parallel if you choose some high amperage cells. If you have access to a 3D printer and could make up some bussbars for the ends, you could make up a nice thin compression or magnet type of pack. Still kinda tough to remove them all to charge. It's pretty easy to wire up a balance plug for such a small pack. And would allow you to still charge with a hobby charger, so economical.

 

[dirtbikr]

Here is the bussbar concept. I am making a jig to get the spring spacing constant, then the batteries will be in a 3D printed compression style holder.

 

[999zip999]

It's always best to use the best cells you can get Samsung 25r or something. 60a do enough in parallel so the pack can easily handle it. Do not run at it's limits. It wouldn't last. With small space build a traditional pack. You would be able to fit in more in parallel better to handle 60amps.
4p minimum.

 

[delta_19]

It's always best to use the best cells you can get Samsung 25r or something. 60a do enough in parallel so the pack can easily handle it. Do not run at it's limits. It wouldn't last. With small space build a traditional pack. You would be able to fit in more in parallel better to handle 60amps.
4p minimum.

Yep the cells I have now are 24 samsung 25r5 just enough for a 6s4p battery.

to give everyone an idea of what im doing and thinking.

im gonna take 12 of those battery sleds and wire them up in pairs with 10AWG solid copper or wet noodle so i have 6 1s4p packs. doing this because max draw of the sammys is 20A and I dont want them pulling there max all the time so 4p will keep it to 15 amp. so now i have at max 15A being pulled from each cell and in to the contacts and in to the wire, and none of the the contacts are touching each other so i know for sure its 15A per contact.

 

[999zip999]

Buy or make some gaskets for the pos. side. Bounce protection. That's the fire ball side. So a little cush on that end. So what is a heavy simple high amp spring. High tension. Screw down ? Maybe dense rubber between a fold. Plus rubber baby bumpers with duct tape on top, simple light. Or Mega wrap. Keep the cowboy in the saddle.

 

[delta_19]

Buy or make some gaskets for the pos. side. Bounce protection. That's the fire ball side. So a little cush on that end. So what is a heavy simple high amp spring. High tension. Screw down ? Maybe dense rubber between a fold. Plus rubber baby bumpers with duct tape on top, simple light. Or Mega wrap. Keep the cowboy in the saddle.

i dont understand any of the jargon you just used, do you want me to put this in some sort of case to make sure the batteries stay in? because i was going to make an aluminium case with a sliding lid that was just touching the top of the cells so that they couldnt fall out, all sides covered in rubber of course.

but none of this is the point of this thread, the point is to discuses if it is at all possible to use 18650 sleds meant for vapes as a way to make a battery case for a 6s4p battery.

 

[999zip999]

Ok it's necessary to have a great contact. The problem with all cell in action is keeping a good contact. Always.
A gasket on the positive side. As the whole can is negative and only the button is negative. ? My battery has 810 cycles so far. Bulk charge and 0.040 balance.
This is why hoover boards catch fire. It's design. Design right.
The mega wrap is like old duct tape packs of old.
I demand a solid electric contact with your load demands. My 80amp controller ( limited by C.A. ) has 132 amp spikes.
Cell holders when bounced around can loose good contact in use.

 

[delta_19]

Ok it's necessary to have a great contact. The problem with all cell in action is keeping a good contact. Always.
A gasket on the positive side. As the whole can is negative and only the button is negative. ? My battery has 810 cycles so far. Bulk charge and 0.040 balance.
This is why hoover boards catch fire. It's design. Design right.
The mega wrap is like old duct tape packs of old.
I demand a solid electric contact with your load demands. My 80amp controller ( limited by C.A. ) has 132 amp spikes.
Cell holders when bounced around can loose good contact in use.

whoa your jumping ahead again, stop making plans for planes when we dont even have the wheel.

so im going to wire 12 of these pack in to a 6s4p config so that when i draw my max im still only pulling 15A a cell (cells in question being 25R5's) on the back side of the contacts is going to be 10AWG solid copper or wet noodle.
here are the contacts in question,
neg: http://www.keyelco.com/product.cfm/For-17-19-mm-Dia-Cell/209/product_id/875
pos: http://www.keyelco.com/product.cfm/For-17-19-mm-Dia-Cell/228/product_id/877

pos is .25mm thick and neg is .30mm

with constant airflow is this going to be suitable for a max draw of 15A?

i think it will be.

 

[Grizzl-E]

25r's won't get that hot running only 15a, so that should be fine in a closed battery case. However placing a bare aluminium sheet in contact with the cells is dangerous. Boards vibrate so much and if the only insulation from the aluminum is the cells shrink wrap cover you may end up wearing through and shorting.

I think 999 is trying to talk you into a traditional pack build. If you are committed to this idea though you should have some type of foam tape inside the aluminium cover. The printed sleds won't be perfectly identical in thickness so you need some slightly soft material to keep the cells from moving.

I wouldn't use any contacts held in by abs printed sleds running these amperages. And I should mention that I have actually done this. My 18650 cell tester is a printed sled for checking laptop cells. I would maybe try what you doing on a bike, but boards are such a rough environment for batteries even when properly welded. Shorts with high amperage cells are pretty scary to deal with.

 

[delta_19]

25r's won't get that hot running only 15a, so that should be fine in a closed battery case. However placing a bare aluminium sheet in contact with the cells is dangerous. Boards vibrate so much and if the only insulation from the aluminum is the cells shrink wrap cover you may end up wearing through and shorting.

I think 999 is trying to talk you into a traditional pack build. If you are committed to this idea though you should have some type of foam tape inside the aluminium cover. The printed sleds won't be perfectly identical in thickness so you need some slightly soft material to keep the cells from moving.

I wouldn't use any contacts held in by abs printed sleds running these amperages. And I should mention that I have actually done this. My 18650 cell tester is a printed sled for checking laptop cells. I would maybe try what you doing on a bike, but boards are such a rough environment for batteries even when properly welded. Shorts with high amperage cells are pretty scary to deal with.

i have a degree in electronics im not that stupid :lol: . the whole case on the inside is going to be insulated with rubber or foam and there will be foam on the cover to force the cells to stay in place.

 

[Grizzl-E]

Ok if you have a degree in electronics then you should know enough to calculate the resistance of the contacts in question and come up with a guess at how much heat they will produce.

Don't be so lazy

 

[delta_19]

Ok if you have a degree in electronics then you should know enough to calculate the resistance of the contacts in question and come up with a guess at how much heat they will produce.

Don't be so lazy

really, really you're gonna be like that?

no need to call me lazy for seeking a second opinion.

look if you dont want to help at all you dont have to keep posting, theres any unsubscribe button too.