Beginners Guide to Processing 18650 Cells | Cell Database


Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
18650 packs without fuses ?????
#1
is it posible to build 18650 packs without fuses ? , without busbars....just nickel stripe and spot welder machine ?... just like batterys from ebikes ! . this packs dont have small fuses and works fine ! . i am waiting for your answers
Reply


#2
(09-07-2017, 08:02 PM)paraskevas Wrote: is it posible to build 18650 packs without fuses ? , without busbars....just nickel stripe and spot welder machine ?... just like batterys from ebikes ! . this packs dont have small fuses and works fine ! . i am waiting for your answers
How many batteries are you planning on melting?
BlueSwordM and paraskevas like this post
Cell progress: 2016/10/17:
180cells@2.0
600cells@2.1-2.6a
70cells@2.7a+

Projects:
Mobile PowerBox
8Kw Powerwall
Insight Parallel PowerPak
1Kw PowerBlade
PowerRack (concept)
12v LED Sconce
Reply
#3
Sure, this is possible. Why wouldn't it? As with all fuses this is just a safety feature. You don't need them for your pack to function, you need them for safety in case it stops functioning properly and something goes wrong. If it makes sense to got without fusing totally depends on the circumstances. Age and condition of your cells, number of cells and so on.

I'm just rebuilding some powertool batteries with new LG HG2 cells. These packs weren't fused in their original condition when they were fitted with Samsung cells and I'm not fusing them now. But they only contain ten cells each in a 2P configuration. My little powerwall with used laptop cells however will be fused, 210 cells for a start in 30P configuration.
Reply
#4
Please post these threads in the correct section. This belongs in the Batteries/Cells section, not the project forum.
BlueSwordM and Korishan like this post
Reply
#5
(09-07-2017, 08:10 PM)Toochi84 Wrote:
(09-07-2017, 08:02 PM)paraskevas Wrote: is it posible to build 18650 packs without fuses ? , without busbars....just nickel stripe and spot welder machine ?... just like batterys from ebikes ! . this packs dont have small fuses and works fine ! . i am waiting for your answers
How many batteries are you planning on melting?

7500 cells 18650
Reply
#6
(09-07-2017, 08:38 PM)paraskevas Wrote:
(09-07-2017, 08:10 PM)Toochi84 Wrote:
(09-07-2017, 08:02 PM)paraskevas Wrote: is it posible to build 18650 packs without fuses ? , without busbars....just nickel stripe and spot welder machine ?... just like batterys from ebikes ! . this packs dont have small fuses and works fine ! . i am waiting for your answers
How many batteries are you planning on melting?

7500 cells 18650

I would definitely use fuses with that many cells. That's going to be a massive amount of short circuit current depending on your parallel configuration. It's not worth risking.
Reply
#7
(09-07-2017, 08:02 PM)paraskevas Wrote: is it posible to build 18650 packs without fuses ? , without busbars....just nickel stripe and spot welder machine ?... just like batterys from ebikes ! . this packs dont have small fuses and works fine ! . i am waiting for your answers

Yes, it is quite possible. Just like a car can be manufactured without airbags. The vehicle will work just fine. It will carry its passengers from point to point as intended. However, if the vehicle ends up in an accident, will the passengers be safe?

That's what fuses are for. IF something goes wrong, they protect all cells involved, and the user (or the users home, car, bike, life, etc....)

At least, that's what the viewpoint of the majority here believe/think (I am pretty certain, anyways; as fuses are a big topic)
Proceed with caution. Knowledge is Power! Literally! Cool 
Knowledge is Power; Absolute Knowledge is Absolutely Shocking!
Dollar Shave Club. Best Razor I've ever used
Certified 18650 Cell Reclamation Technician
Reply
#8
If you put your 7500 cells in series for a nice little ~28 kV pack, then yes, you can probably get away without using cell fuses. But since you are probably not doing that you should fuse your pack. For a 48V system with 14S configuration you will have over 500 cells in parallel. That will be a HUGE amount of current if something goes horribly wrong. Even if you further double the voltage this would still be a huge current.
Reply
#9
Yep. With that much energy, you need fallbacks.
The question is not if it's going to happen, but when it's going to happen.
The power of lithium ion is in our hands!
We'll show them what we're made of!
Reply
#10
Yes it works but... What type of cells?
For instance if you buy new cells they are generally not fused and i would say its not needed. For instance my whole LiFePo4 pack isnt fused between cells. They come like that from factory so I trust them

BUT
2nd hand cells in powerwalls I dont trust and therefore fuse.
For smaller projects i generally dont fuse either. Like ATV batteries and other. it goes heck alot faster just to spot them together or solder them. No issue so far...
mormor1971 and BlueSwordM like this post
Follow me! >> YouTube / Forum system setup / My webpage  Diy Tech & Repairs

Current: 10kW Mpp Hybrid | 4kW PIP4048 | 2x PCM60x | 83kWh LiFePo4 | 10kWh 14s 18650 |  66*260W Poly
Upcomming: 14S 18650~30kWh | Automatic trip breakers, and alot more
Reply


Who read this thread?
57 User(s) read this thread:
André Coutinho (11-17-2017, 03:06 AM), Herbi (09-11-2017, 04:57 PM), zombielinux (09-11-2017, 01:02 PM), SimonW (09-08-2017, 07:31 AM), floydR (09-11-2017, 02:18 AM), NZ55 (09-07-2017, 09:58 PM), Ivo Staelens (09-09-2017, 05:48 AM), jrandomb (09-08-2017, 12:12 AM), Geek (09-11-2017, 05:21 AM), shuai (09-09-2017, 09:52 PM), ivnz (09-15-2017, 05:25 AM), paraskevas (09-15-2017, 06:25 AM), Travis Watson (09-08-2017, 02:25 PM), DarkRaven (09-08-2017, 07:25 AM), v850tw (09-08-2017, 03:12 AM), yasko (11-16-2017, 09:49 PM), Sameera Rodrigo (10-07-2017, 04:19 PM), rev0 (10-03-2017, 10:35 PM), accoelho (10-05-2017, 11:45 AM), dougm352 (09-28-2017, 06:59 PM), slimf (10-13-2017, 11:56 AM), mormor1971 (09-25-2017, 09:50 AM), WallBender (09-17-2017, 05:05 AM), jesse.rizzo (09-17-2017, 02:50 PM), zag2me (09-11-2017, 09:22 PM), JeffP (09-08-2017, 08:15 AM), John Andrew (09-07-2017, 10:12 PM), mayson14 (09-11-2017, 11:11 PM), KtB (09-09-2017, 07:34 AM), Nitroghost (09-09-2017, 12:04 AM), wim (09-08-2017, 02:56 PM), jdeadman (09-08-2017, 12:41 PM), flight4900 (09-08-2017, 01:24 PM), JGaspar (09-22-2017, 02:43 AM), Darmok (09-18-2017, 01:37 AM), whisperbot (09-08-2017, 07:45 PM), PAF (09-09-2017, 06:37 PM), A + A (09-08-2017, 06:57 AM), Korishan (09-08-2017, 10:47 AM), Majorphill (09-09-2017, 02:29 AM), Toochi84 (09-07-2017, 09:16 PM), mike (09-08-2017, 12:26 PM), frnandu (09-10-2017, 01:22 AM), Brian Drury (09-09-2017, 06:40 PM), BlueSwordM (09-08-2017, 11:31 AM), rainbowwarrior38 (09-08-2017, 10:39 AM), Emmanuel Ory (09-10-2017, 09:54 AM), Stefaan De Ridder (09-08-2017, 07:18 AM), Hanssing (09-08-2017, 07:13 PM), fcbrand (09-10-2017, 10:28 PM), jesusangel (09-07-2017, 09:31 PM), Dan Lim (09-07-2017, 10:10 PM), watts-on (09-08-2017, 10:22 AM), neilmc (09-08-2017, 11:25 AM), kktuo (09-08-2017, 06:46 AM), typ49 (09-08-2017, 08:44 AM), daromer (09-08-2017, 06:30 AM)

Forum Jump:


Users browsing this thread: 1 Guest(s)