Beginners Guide to Processing 18650 Cells | Cell Database


Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
Starting a new DC WALL in Mexico
#1
Hey guys, im starting a new pack for dc devices only, this is a 11.1 nominal pack, 3s and 33p (or 33p and 3s ???)
i got new samsung and lg cells from ebay, they are ebike battery packs that i disassembled.



since this are new cells i used the ***** hardware on the first pack to see how they worked, since i'm not ass good on soldering. my experience on the ***** is actually not that good, they are hard to get them all together, and after that i had to make sure all the cells had good contact with the caps, witch they did not, had to disassemble part of the pack twice to get it correctly done.

I installed a 26 gauge wire as a fuse for protection, these cells are 4.4 AH so that worked perfect, after that i used XT60 connectors for the final cables, i did place a cable for charging and another for discharge on the opposite side of the pack, charging side has a BMS.




TODO:

i orderd a dc step up to connect the battery to the diferent devices that i whant to connect, router, network switch, ubiquiti antena, small pc for survaillance, survaillance cameras... ill post more pics once i have all that connected and arranged.

please leave your comments ! thanks for reading 

my youtube: https://www.youtube.com/user/saulgonzalez76
Reply


#2
Welcome....

Nice idea...
Reply
#3
I like the idea of the pre made units, but very unsure of the added resistance.
It looks to me, that the tabs just touching the ends of the battery could cause problems with heat.

Just my thoughts.
Reply
#4
What i seen so far those packs actually doesnt save any time neither do they work that well. You need to press them together very tight and have no guarantee that they stay like that unless you force them to it.

Neither less welcome and will be fun to see your projects!
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
#5
(07-05-2017, 11:17 AM)daromer Wrote: What i seen so far those packs actually doesnt save any time neither do they work that well. You need to press them together very tight and have no guarantee that they stay like that unless you force them to it.

Neither less welcome and will be fun to see your projects!

Yes, you are correct, it acctually not a great product, my next packs will be made difrent.
Reply
#6
I'm actually going to make my packs using the similar contacts that are in the cell holders with the tabs. They are "very" tight connections and I haven't noticed much resistance (though I haven't fully tested this). It's gotta be better connection than the style you have there.

I did see their video on assembly and how they are made. I think the spring is too weak to make sure it has solid contact, the spring coil causes excessive resistance (and during a short may actually be a downfall as the fuse may not blow; I think). I like the bolting option, but it needs to be more friendly. It seems the assembly takes about the same time as soldering.

However, it's nice that there's someone here who has that setup and can share their experience with it Smile
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
#7
I now have an issue, not sure if this is normal, i ilstalled a 3s bms on the battery, now the voltage are:
bank 1: 4.23v
bank 2: 4.19v
bank 3: 4.09v

if i keep charging the bank one goes up to 4.25v, is this safe?, that's the bms stop charge limit. also, should i keep charging the battery until bank 3 its full ?

(07-06-2017, 03:02 PM)Korishan Wrote: I'm actually going to make my packs using the similar contacts that are in the cell holders with the tabs. They are "very" tight connections and I haven't noticed much resistance (though I haven't fully tested this). It's gotta be better connection than the style you have there.

I did see their video on assembly and how they are made. I think the spring is too weak to make sure it has solid contact, the spring coil causes excessive resistance (and during a short may actually be a downfall as the fuse may not blow; I think). I like the bolting option, but it needs to be more friendly. It seems the assembly takes about the same time as soldering.

However, it's nice that there's someone here who has that setup and can share their experience with it  Smile

hi, Korishan

i cancelled another order of *****, because if one cell goes bad i would have to disassemble the hole pack instead of just pulling out that cell, i will be making the pack with plastic holders instead.
Reply
#8
I would check the cells with a Good multimeter. There might be a calibration error with the bms or the cell voltages are just too high. ideally you don;t want a cell to be above 4.1 for better life
Reply
#9
Or u charge more than the bms can balance. One of the issues with cheaper ones with no feedback. If bms balance with 50mA as example ur not allowed to top charge with more either
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
#10
If cells are getting over 4.2V, do not keep charging the pack to bring the others up. This will shorten the lifespan of the over charged cells dramatically. If you can disconnect the cells that are over charged that would be best.
But it sounds like your bms is not functioning as intended. Test it out with 3 cells in series to see how it handles those.
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


Who read this thread?
57 User(s) read this thread:
Bert (Yesterday, 10:51 PM), Chicken (07-05-2017, 12:02 PM), Chiptosser (07-12-2017, 02:38 AM), AzJames (07-05-2017, 07:51 PM), Stefaan De Ridder (07-16-2017, 02:27 PM), kazbach (07-10-2017, 12:14 AM), ismaildoganw (07-09-2017, 07:25 PM), kot (07-06-2017, 06:53 PM), Taz D'vil (07-08-2017, 01:00 AM), DrkHrs13 (07-09-2017, 12:30 PM), IronSky (07-06-2017, 09:14 PM), Saul Gonzalez Villafranca (07-06-2017, 07:57 PM), Fredd (07-07-2017, 05:55 AM), burromanadero (07-05-2017, 03:41 AM), roel.nagels@telenet.be (07-06-2017, 06:00 PM), Pato Llaguno (09-13-2017, 05:41 PM), fixtec (09-04-2017, 01:10 PM), abhijithym (09-17-2017, 05:35 PM), jgalton (08-24-2017, 09:17 PM), AirDogU2 (09-21-2017, 07:56 PM), John Southern (08-28-2017, 10:21 AM), WildCard_25 (08-28-2017, 06:46 AM), al4sound (08-12-2017, 02:28 AM), Jimmy Home (07-22-2017, 08:01 AM), pruesel (09-17-2017, 09:35 AM), alildabldo (07-10-2017, 01:37 PM), Piotr Dziel (07-08-2017, 07:51 PM), MetalFang (07-11-2017, 08:32 PM), Hanssing (07-09-2017, 06:40 PM), Daggerzz (07-16-2017, 02:26 PM), egam (07-08-2017, 03:25 PM), Tristan Timmer (07-09-2017, 12:05 AM), Scepterr (07-07-2017, 04:15 AM), Wattsup (07-05-2017, 09:29 AM), PAF (07-09-2017, 02:49 PM), Korishan (07-09-2017, 03:37 PM), coolfx (07-09-2017, 10:36 AM), Majorphill (07-07-2017, 02:06 AM), VdVoort4 (07-05-2017, 11:04 AM), RudyLiPower (07-05-2017, 03:22 AM), BigBen (07-05-2017, 04:19 AM), mike (07-05-2017, 11:49 AM), Droid126 (07-05-2017, 01:58 AM), jdeadman (07-09-2017, 05:31 PM), jesusangel (07-10-2017, 05:13 AM), Dan Lim (07-05-2017, 04:08 AM), watts-on (07-06-2017, 08:36 PM), dinoN17 (07-11-2017, 08:29 AM), kktuo (07-12-2017, 04:45 PM), 1958 greyhound (07-09-2017, 11:00 AM), Jeremy Choy (07-05-2017, 03:11 PM), The-J-Man (07-09-2017, 10:32 AM), typ49 (07-10-2017, 07:16 AM), frnandu (07-09-2017, 06:50 PM), wim (07-09-2017, 02:41 PM), 2146 (07-05-2017, 01:47 PM), daromer (07-09-2017, 10:38 AM)

Forum Jump:


Users browsing this thread: 1 Guest(s)