is there a prob in this battery diy plan with prebuid case?

they are not fuses, they are PTC's. they protect the cell against overheating,pressiure and other assorted damage that might result in a "RUD". its a safety valve that opens the inner cell to the outside air and breaks the electrical connection.
 
flippy said:
they are not fuses, they are PTC's. they protect the cell against overheating,pressiure and other assorted damage that might result in a "RUD". its a safety valve that opens the inner cell to the outside air and breaks the electrical connection.
Click to expand...

Will those pop in the case of an external short?
 
Dak77 said:
flippy said:
they are not fuses, they are PTC's. they protect the cell against overheating,pressiure and other assorted damage that might result in a "RUD". its a safety valve that opens the inner cell to the outside air and breaks the electrical connection.
Click to expand...

Will those pop in the case of an external short?
Click to expand...
Only if the cell itself wold explode. So generally no. But per cel fusing is stupid and should notbe done.
PTCs are like spinklers, airbags or body armour. A last resort and using it means you got WAY bigger problems.
 
So why are you planning to use vape pen cells instead of cells that match the application?


20pcs-3-7v-15Ah-Lithium-lipo-polymer-cell-1174170-3-7v-16Ah-17ah-for-diy-battery.jpg
 
batteries like the HE4 can handle more current then you would ever need without having pouches doing their "zwelgje" routine.
(aka: thats a cute little harmless cartoon dragon that gets larger, breathes fire and kils everyone around him when it gets angry)

cheap chinese pouches are never to be recommended, especially not to padawans....
 
Chalo said:
So why are you planning to use vape pen cells instead of cells that match the application?


20pcs-3-7v-15Ah-Lithium-lipo-polymer-cell-1174170-3-7v-16Ah-17ah-for-diy-battery.jpg
Click to expand...

chalo you are recommanding me rectangular cell instead of vtc4 sony exact? why exaclty? tx what are their cost and price, pros and cons
 
flippy said:
batteries like the HE4 can handle more current then you would ever need without having pouches doing their "zwelgje" routine.
(aka: thats a cute little harmless cartoon dragon that gets larger, breathes fire and kils everyone around him when it gets angry)

cheap chinese pouches are never to be recommended, especially not to padawans....
Click to expand...

hi Flippy, you are introducing the He4, never heard of it, my google search tell me those are 18650 cells. Is this what chalo was refering to? i mean his picture is rectangular.
 
99t4 said:
want to build said:
I know that is a lot of questions, i would apreciate if you could answer them all even if the answer is dont know.
Click to expand...
OK, I don't know, for all the questions except for your question #10:

want to build said:
10)Would you say that the point of suggesting me to read the link is to look at the image and not to suggest me going in the way of using fuse wire?
Click to expand...
No, the point suggesting you read the link was mainly for you to see the image (BTW, not that image you referred to with all the numbers, but the one before it) to see where the center pin meets the bottom anode (-) cap, in the center, where it is not recommended to solder, or even spotweld. As you seemed to be unsure of the reason to avoid heat-stressing that immediate area.

I mentioned the (not)fuses, as, since that article was written, there has arisen some controversy on whether those are even in fact fuses. Didn't want anyone reading this in the future to get the wrong idea either.
Click to expand...
Ok i draw a circle in blue . is this the spot you and goatman are talking about?
what is the problem there? is this center rod conductive or non conductive?
does it have a structural purpose or conductivity purpose. can you clarify? tx
 

Attachments

  • centre.png
    centre.png
    59 KB · Views: 597
want to build said:
Chalo said:
So why are you planning to use vape pen cells instead of cells that match the application?


20pcs-3-7v-15Ah-Lithium-lipo-polymer-cell-1174170-3-7v-16Ah-17ah-for-diy-battery.jpg
Click to expand...

chalo you are recommanding me rectangular cell instead of vtc4 sony exact? why exaclty? tx what are their cost and price, pros and cons
Click to expand...

The point is, why build a pack with 52 cells when you could build an equally capable pack with 13 cells? Less work, fewer points of failure.
 
please stop with the "points of failliure" BS. its simply not true. especally not when you consider the short lifespan of pouches without a good compression housing.
 
Chalo said:
want to build said:
Chalo said:
So why are you planning to use vape pen cells instead of cells that match the application?


20pcs-3-7v-15Ah-Lithium-lipo-polymer-cell-1174170-3-7v-16Ah-17ah-for-diy-battery.jpg
Click to expand...

chalo you are recommanding me rectangular cell instead of vtc4 sony exact? why exaclty? tx what are their cost and price, pros and cons
Click to expand...

The point is, why build a pack with 52 cells when you could build an equally capable pack with 13 cells? Less work, fewer points of failure.
Click to expand...
HI chalo, i m an open person always willing to learn. the truth is that i did not know they exist. could you paste the spec of the cell you talk about , their price and a short pros and cons of using them instead on 18650 and then I will try to bring back the questions of what is the problem with the rod in 18650 cause it is still :) a mystery for me ;) . You are welcome to share your info , please use facts and data so we can see what you mean .
I wonder what you consider point of failure, do you mean more welding so like more chances to do a bad weld?
 
want to build said:
[could you paste the spec of the cell you talk about , their price and a short pros and cons of using them instead on 18650
Click to expand...

I'm not recommending any specific cell; there are at least dozens of cells to choose from in the capacity range you want. Use a search engine on "lithium ion 10Ah cell" or whatever capacity you have in mind. The goal is to find prismatic, pouch, or larger cylindrical cells that will give you the Ah capacity you want in a single cell, so you don't have to weld bunches of them together in parallel.

I wonder what you consider point of failure, do you mean more welding so like more chances to do a bad weld?
Click to expand...
Yes, more welds means more places to have a bad electrical or mechanical connection. But that's only one of the problems with using a relatively large pack built up from vape pen cells.

The 13S battery I use has no welds in it at all. The cells have threaded studs, and I attached small copper bus bars to them to put the cells in series.

If you weld the cells, you not only heat damage them to some degree, but your pack's performance can be limited by the connecting strips (especially with high current cells like VTC4).
 
want to build said:
... what is the problem with the rod in 18650 cause it is still :) a mystery for me ;) .
Click to expand...
The anode rod comes in contact with the center of the can end thus any soldering or spot welding should preferably be done off-center closer to bottom can edge than at the center. Whereas the protective (explosion proof) cathode cap more easily dissipates any excess soldering or spot welding heat due in part to an inexperienced novice builder with less than desirable equipment prolonging the weld time.
 
want to build said:
... what is the problem with the rod in 18650 cause it is still :) a mystery for me ;) .
Click to expand...
The anode rod comes in contact with the center of the can end thus any soldering or spot welding should preferably be done off-center closer to the can edge than at the center. Whereas the protective (explosion proof) cathode cap more easily dissipates any excess soldering or spot welding heat. Due in part to an inexperienced novice builder with less than desirable equipment prolonging the solder or spot weld time and cell damage.
 
eMark said:
want to build said:
... what is the problem with the rod in 18650 cause it is still :) a mystery for me ;) .
Click to expand...
The anode rod comes in contact with the center of the can end thus any soldering or spot welding should preferably be done off-center closer to the can edge than at the center. Whereas the protective (explosion proof) cathode cap more easily dissipates any excess soldering or spot welding heat. Due in part to an inexperienced novice builder with less than desirable equipment prolonging the solder or spot weld time and cell damage.
Click to expand...

are you sayin the center pin on my 28 april picture is an anode?
if yes since the bottom part of the cell is an anode to, what is the problem with welding on top on it?
 
flippy said:
batteries like the HE4 can handle more current then you would ever need without having pouches doing their "zwelgje" routine.
(aka: thats a cute little harmless cartoon dragon that gets larger, breathes fire and kils everyone around him when it gets angry)

cheap chinese pouches are never to be recommended, especially not to padawans....
Click to expand...

guys, i would like to ear your shoot on why the cells shown by chalo are not advised for inexperiences welder because he does make a point in saying i is more simple but i have to have the other side of the medal too.
is it because vtc4 have protection device pouches have not?
Chalo you can also tell the negative of the pouches you recommand to have a global view about them pros cons
 
I don't know anything about those specific cells, except that they're in the Ah capacity range you were discussing. One of my batteries uses PHEV2 format prismatic cells with threaded studs. The other one uses a pouch cell pack from a Mercedes-Benz. I'd put the reliability and safety of either one above any pack made of vape pen or flashlight cells.
 
Chalo said:
I don't know anything about those specific cells, except that they're in the Ah capacity range you were discussing. One of my batteries uses PHEV2 format prismatic cells with threaded studs. The other one uses a pouch cell pack from a Mercedes-Benz. I'd put the reliability and safety of either one above any pack made of vape pen or flashlight cells.
Click to expand...

hi can you link 2 or 3 shopping link of those cells so i have an idea of the cost? tx
 
want to build said:
Chalo said:
I don't know anything about those specific cells, except that they're in the Ah capacity range you were discussing. One of my batteries uses PHEV2 format prismatic cells with threaded studs. The other one uses a pouch cell pack from a Mercedes-Benz. I'd put the reliability and safety of either one above any pack made of vape pen or flashlight cells.
Click to expand...

hi can you link 2 or 3 shopping link of those cells so i have an idea of the cost? tx
Click to expand...

The PHEV2 cells came from an Endless Sphere user. https://endless-sphere.com/forums/viewtopic.php?f=9&t=93941

The Mercedes-Benz pack came from Battery Hookup, who haven't had them for a long time.

I don't think either of these options is still available. The point is that you have other options besides rinky-dink round cells that would work better for what you're doing, might be cheaper, and would definitely be easier to build with.
 
hi they were 25 usd for 1 rectangle , how many would it need to be similar to 13s 4p vtc4?

i looked at a site it seems cylindrical is abit safer https://batteryuniversity.com/learn/article/types_of_battery_cells
 
want to build said:
hi they were 25 usd for 1 rectangle , how many would it need to be similar to 13s 4p vtc4?
Click to expand...

One 25Ah PHEV2 cell is equivalent to 12 VTC4 cells, in terms of energy storage.

It has two screw terminals, rather than 24 terminals that must be welded.
 
Chalo said:
want to build said:
hi they were 25 usd for 1 rectangle , how many would it need to be similar to 13s 4p vtc4?
Click to expand...

One 25Ah PHEV2 cell is equivalent to 12 VTC4 cells, in terms of energy storage.

It has two screw terminals, rather than 24 terminals that must be welded.
Click to expand...

Hi im two noob to calculate the energy storage in 13s 4p ... i used to be able but gosh planning a battery construction takes took me so much time and still isn t settle
 
want to build said:
Chalo said:
want to build said:
hi they were 25 usd for 1 rectangle , how many would it need to be similar to 13s 4p vtc4?
Click to expand...

One 25Ah PHEV2 cell is equivalent to 12 VTC4 cells, in terms of energy storage.

It has two screw terminals, rather than 24 terminals that must be welded.
Click to expand...

Hi im two noob to calculate the energy storage in 13s 4p ... i used to be able but gosh planning a battery construction takes took me so much time and still isn t settle
Click to expand...

A VTC4 cell contains 2100 mAh at a nominal 3.7 volts. 2.1 * 3.7 = 7.77 watt-hours per cell.

A parallel group of four VTC4 cells contains 31.08 watt-hours. A 13S 4P pack contains 404 watt-hours.
 
Chalo said:
It has two screw terminals, rather than 24 terminals that must be welded.
Click to expand...

why do you keep making it sound like welding is a bad thing? pretty sure there are more welds in a car then bolts.
 
flippy said:
Chalo said:
It has two screw terminals, rather than 24 terminals that must be welded.
Click to expand...

why do you keep making it sound like welding is a bad thing? pretty sure there are more welds in a car then bolts.
Click to expand...

That's kind of a hassle when you have to replace a piece of of a car body, isn't it? Also, cars aren't packed full of thin plastic films and moist chemicals just on the other side of the sheet metal when it's welded.

Would you prefer that your electric motor were welded together? Those need less frequent service that batteries do, in my observation.
 
You must log in or register to reply here.

Similar threads

O
Lifepo4 cylinder 32650 cells simplified stationary design idea?
Replies
7
Views
166
jonescg
jonescg
W
DIY Arduino Battery Spot Welder et 48 v?
2
Replies
41
Views
2,446
john61ct
J
W
how many amps should i plan for a Diy battery and which nickel strips?
Replies
16
Views
2,177
want to build
W
M
How Can I Improve My Spot Welds When Building Battery
Replies
12
Views
1,877
d8veh
D
A
How to a DIY 18650 battery?
Replies
10
Views
3,678
Arbol
A
Back
Top