Solved About PCB's...

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Mumble

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So, as many of you know, my first portable didn't have a PCB in it.
I bought a 14.8v pack which I found from the Portablizing BOM
http://www.ebay.com/itm/121611468285?_trksid=p2060353.m1438.l2649&ssPageName=STRK:MEBIDX:IT

And it works really well. The problem was their was no protection, so once the cells died, they have a chance of dying. BUT, I found something interesting. When the wii shut off, and I didn't have a charger, I used my multimeter to measure the voltage of each cell. Each one was about 1.6v - 1.8v each.

The Wii doesn't turn on with them this low (You'll get a red light for a split second if you're lucky), with all four cells combined, it's about 7v.

So I just thought I should give an update, and also a "Sort Of" question.

I don't see a reason to get a PCB if the cells still have half of their juice before the Wii shuts off.

Is there still a reason to get one?
 

Luke

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As stated in your worklog, over-discharging batteries will significantly lower the lifespan of the cells, if not kill them outright. Over-discharge protection is one of the functions of the pcb. Everyone keeps telling you to get a pcb. You make the call.
 

Mumble

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As stated in your worklog, over-discharging batteries will significantly lower the lifespan of the cells, if not kill them outright. Over-discharge protection is one of the functions of the pcb. Everyone keeps telling you to get a pcb. You make the call.
Yeah. I ordered a PCB for my next portable I'm making for a bud just to be sure his cells are good. But what I mean, is I don't understand how the batteries can get over discharged with a spare 7v...
 

Shank

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The answer to this question is always yes. You NEED protection circuitry for any rechargable lithium battery pack. Always. End of story. It's not just for protection of the batteries, but they can explode into ferocious balls of fire when mistreated. Seriously, just get a damn PCB.

Edit:
I don't see a reason to get a PCB if the cells still have half of their juice before the Wii shuts off.
Half voltage does not mean half the charge left. Go look up a discharge curve for a lithium battery for a more in-depth look. At less than 2 volts, you are definitely screwing your batteries.
 
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Luke

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Yeah. I ordered a PCB for my next portable I'm making for a bud just to be sure his cells are good. But what I mean, is I don't understand how the batteries can get over discharged with a spare 7v...
Yeah seriously, maybe you are blissfully unaware, but li ions aren't safe things and it's nonsensical to forego the protection circuit.

If you're skeptical on what the minimum safe discharge for one is, that question doesn't necessarily need to be posted on bitbuilt because a simple google search can do the trick: http://bfy.tw/AnbN

But again, get a protection circuit, and it will stop the batteries from discharging below a non-safe point.
 
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Just to add, it used to be illegal (at least in this country) to buy cells without a protection circuit attached... That should give you an idea :P
 

Mumble

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So, I'm going to trash these batteries and just buy the same ones with a built in PCB. Sure, it would definitely be cheaper to buy a PCB, and mount in somewhere on my case, but I have no room to put it, and I have waaay too much hot glue to even think about opening the case.

Everyone cool with this idea?

http://www.ebay.com/itm/4x-Keeppower-Protected-18650-3400mAh-with-Panasonic-NCR18650B-Li-ion-Battery-PCB/112258581078?_trksid=p2060778.c100290.m3507&_trkparms=aid=111001&algo=REC.SEED&ao=1&asc=20160727114228&meid=5c6ab6de7af64e028314c9285b8fd0f3&pid=100290&rk=2&rkt=4&sd=302033263407
 

GC64

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So, I'm going to trash these batteries and just buy the same ones with a built in PCB. Sure, it would definitely be cheaper to buy a PCB, and mount in somewhere on my case, but I have no room to put it, and I have waaay too much hot glue to even think about opening the case.

Everyone cool with this idea?

http://www.ebay.com/itm/4x-Keeppower-Protected-18650-3400mAh-with-Panasonic-NCR18650B-Li-ion-Battery-PCB/112258581078?_trksid=p2060778.c100290.m3507&_trkparms=aid=111001&algo=REC.SEED&ao=1&asc=20160727114228&meid=5c6ab6de7af64e028314c9285b8fd0f3&pid=100290&rk=2&rkt=4&sd=302033263407
If you're going to do that, why wouldn't you just buy the panasonic 18650s from the portablizing BOM for almost half the price, then buy the PCB to go with it for an extra 2$? It saves you like 20$.
 

Mumble

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If you're going to do that, why wouldn't you just buy the panasonic 18650s from the portablizing BOM for almost half the price, then buy the PCB to go with it for an extra 2$? It saves you like 20$.
Like I said. No room. :P
 

Mumble

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¯\_(ツ)_/¯

Edit: I honestly don't care about prices. I just want to know if this is a fix.

Edit Edit: Sorry I didn't see the pic. It was small, and I honestly thought it was apart of your signature for some reason :P. That PCB is pretty small. But if I'm completely honest, I don't want to work on this anymore. I'm already ordering parts for my next one. Going with the protected cells, and honestly the money doesn't bother me.
 
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Madmorda

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So, I'm going to trash these batteries and just buy the same ones with a built in PCB
I don't see a reason to get a PCB if the cells still have half of their juice before the Wii shuts off.
Mumble, we've been over this at length in your worklog. Either buy the pcb or go with Shank's idea of one attached to a holder. I keep telling you that those individual protected cells =/= a pack with a protection pcb for the pack.

You need to either do this right or not use batteries in your build. Honestly I'm really concerned that you're building a portable for a friend because you clearly aren't concerned at all about your portable exploding. As in, FOOM!, you wake up and you've set your parents house on fire. Or as in BANG!, you have to go to the doctor to have them pull pieces of metal and corrosive battery materials out of your hand.


I guess you have the right to set your crotch or fingers on fire if you're really set on it. But consider that your friend trusts you to build him/her something safe. I know I'm coming off as dickish here, but it's really important that you understand that these aren't to be toyed with, especially if you're bringing someone else into it.
 

Mumble

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Not that. That's not funny. I'm just laughing at the fact of how much of a big deal this has made. :/
Sorry everyone, I'm probably being that one guy. I just don't understand how advertised cells that say are protected aren't protected. I'm still a bit of a nub skrub.
 

Luke

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I already showed him that, he doesn't want to have to open the Wii to resolder the wires.
What makes you think he has to open the wii for that?
The wires are literally just hanging loose right there, all he has to do is snip them and attach the new holder.
 
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