18650 Battery Bank

Started by Jumbicat, July 05, 2016, 12:50:33 AM

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Jumbicat

Has anyone built a 18650 Cell battery bank that's designed around the Kid's spec's?
I bought a kid when they first came out and it's still sitting in the box along with (2) Grape Solar 250 watt Poly panels.
Looking into battery banks and thought I'd ask this group their thoughts before I call and bother Midnight's support.
Mark

dgd

Excuse my ignorance, but what is a 18650 cell battery bank?

Dgd
Classic 250, 150,  20 140w, 6 250w PVs, 2Kw turbine, MN ac Clipper, Epanel/MNdc, Trace SW3024E (1997), Century 1050Ah 24V FLA (1999). Arduino power monitoring and web server.  Off grid since 4/2000
West Auckland, New Zealand

TomW

#2
Quote from: dgd on July 05, 2016, 03:34:42 PM
Excuse my ignorance, but what is a 18650 cell battery bank?

Dgd

18650 type  Lithium Ion cells?

Gotta love the guess what I mean game .  ;D

Pretty sure he means those little AA or AAA size cells. Or not.

Tom
Do NOT mistake me for any kind of "expert".

( ͡° ͜ʖ ͡°)


24 Trina 310 watt modules, SMA SunnyBoy 7.7 KW Grid Tie inverter.

I thought that they were angels, but much to my surprise, We climbed aboard their starship and headed for the skies

russ_drinkwater

They are a super sized lithium ion battery 3.7 volts and around 3.4 amps.
I use them in torches and headlamps.
Also they are used in electric smoke pipes and the like.
Standalone. 20 Hyundai x 220 watts panels, 2 x classic 150's, Latronics 24 volt 3kw inverter, Whiz bang Jnr, 12 Rolls surrete  4KS 25P  batteries and WBJ.
Grid tie feed-in, 12.5 kw in 3 arrays generating 50 kws per day average. Solar river grid tie inverters

binkino

also known from laptop battery packs.
Open some old packs and get some 18650 for the e-cigarette :D
PV-OUTPUT: http://pvoutput.org/list.jsp?id=38617
Classic Lite 200 + Classic 200 + Easun ISolar-SMX-II-5.6KW + 12x240Wp + 12x255Wp + 2x10kWh LFP
http://a68k.de/Solar/Monitor_LC2.php

ClassicCrazy

Are you talking about using used LiPo 18650 cells ?
Can be dangerous and cause fires charging those if they get out of balance.
Go to Endless Sphere forums and look up battery technology section there.
https://endless-sphere.com/forums/viewforum.php?f=14&sid=5ebbb98d782b8d1a8a16daae3541edaf
Many discussions on building packs with those.
Not a good idea unless  you have proper balancing BMS system and a fire proof place to put the battery bank !

Larry
system 1
Classic 150 , 5s3p  Kyocera 135watt , 12s Soneil 2v 540amp lead crystal for 24v pack , Outback 3524 inverter
system 2
 5s 135w Kyocero , 3s3p 270w Kyocera  to Classic 150 ,   8s Kyocera 225w to Hawkes Bay Jakiper 48v 15kwh LiFePO4 , Outback VFX 3648 inverter
system 3
KID / Brat portable

Jumbicat

#6
Thanks Larry, I'll check out the discussion.
Mark
Edit: different style of battery. 18650's are a lot safer from what I've read.

ClassicCrazy

Quote from: Jumbicat on July 06, 2016, 03:55:59 AM
Thanks Larry, I'll check out the discussion.
Mark
Edit: different style of battery. 18650's are a lot safer from what I've read.

LiFePo4 are safer , LiPo will make fires much more easily from what I have read up on them.
Some of the ebike crowd on the Endless Sphere will post photo's of burned up walls in their garage or burned up bikes - usually caused because they bulk charge their battery packs instead of balance charging them. When they get an imbalance things can get very hot .
I have been using LiFePo4 Headway 10 AH lithium battery on my ebike for last 5 years and no problems, even though I have made some very poor mistakes at imbalance charging before I knew better.
There is a video on internet where a guy intentionally abuses different types of Lithium cells to see what happens and which ones burn up and which don't do that very easily.
If you want to use lithium batteries for solar - these days the choice seems to be CALB batteries . Maybe when and if Tesla really ever starts making their lithium storage packs and you can actually buy one for what they were advertising price as - that will be the better one but not on the market now .
Larry
Larry
system 1
Classic 150 , 5s3p  Kyocera 135watt , 12s Soneil 2v 540amp lead crystal for 24v pack , Outback 3524 inverter
system 2
 5s 135w Kyocero , 3s3p 270w Kyocera  to Classic 150 ,   8s Kyocera 225w to Hawkes Bay Jakiper 48v 15kwh LiFePO4 , Outback VFX 3648 inverter
system 3
KID / Brat portable

Jumbicat

#8
I'm not using "Fake" or factory rejects which are most likely the cause of most problems.  I'm harvesting cells from notebook batteries and or medical devices.  Each cell is being stressed test to find it's capacity.  Hopefully, I'll be able to build a pack that all cells are at least 2000mah.  It's going to take time to find, sort, test and re-test before fabrication starts.  I'll fuse each cell to be safe.

Not sure it's going to be worth the effort.  I'd buy a Tesla Powerwall but not ready to invest in required hardware to run one. They should be available in 2017. I understand 2016 is already sold.

I do like the CALB batteries.  Some projects I've been following have replaced the CALB bank with 18650 banks.  (Samba Project)  Too soon to find out if the change is worth it. There's a few folks that have built powerwalls using 18650 cells.  I hope they are forthcoming on any downside to using 18650 cells. Internet is nice, but need to understand some stuff on YouTube is complete utter bu**sh%t.

Mark

Edit: I might add that when researching solar charge controllers, I read where a couple of engineers left OutBack to start their own company.  They wanted to add additional features and were told no? Or they had a different approach to design.  That's what I took away from the article.  I bought the kid and from what little I've used it, I'm very happy with it.  I'm sure with the right parameters, it will charge LiPo batteries safely.