You and I have come across that “G Max” pack before. Me personally and you vicariously, thru me.
Check out post 79 of this thread. (link only works with default BLF posts per page of 30)
Be careful with that one, a very wise person warned me
“Damn, dcho. You brave (or maybe a bit crazy). This thing looks like a short challenge with an attitude”
.
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Have fun, that pack yielded great cells for me.
a\also, save the connectors on the BMS board from that G Max pack. They mate with the connectors on the 18V Ridgid battery packs. Could come in handy if you want to use an 18V Ridgid to power some future project.
(Like maybe a combo Lantern - USB charger - MP3 player - Bluetooth Speaker - coffee maker) :partying_face:
Ha! Now I know why I had a moment of Déjà vu when I first saw the pack. Glad mine only had 10 cells because that 20 cell pack you got looks intimidating to me.
All I could initially find was some info on the cells. Pretty much all I could find was, as ImA4 guessed, they were Chinese.
But your info invigorated me, and I thought to scan the QR code on the battery pack with my cell phone app.
And you were right, this pack is a high amp pack that came from a hoverboard!
A…much…more…interesting…pack.
Now I WILL test the condition and report back.
looks like it was designed to be safe.and not go nuclear if some kid gets it into a stall condition.
if those cells actually have the i.r shown they will be good for more demanding lights and tools.
Yes, apart from the welds it looks like it is well built. That BMS board has 4 power FETs. It’s not made super cheaply.
I am in the process of charging it up and I will discharge it through 6 ohms of power resistors. I shall report how it does.
In the mean time, I have another pack that looked interesting. I don’t have great hopes on the cells inside, I’m just curious to know.
This one is from a Defibrillator! This one must have some really high quality, reliable cells.
Whatever they are.
The top was glued on and came right off, revealing a circuit board,
The circuit board resisted a little, but finally gave in to my persuasion.
WAIT, what the?
.
.
…
Sorry, couldn’t help myself. I thought of this the second I pulled this pack out of the bin and saw it went to a Defibrillator
What it really contained was this,
Boring, and they were dead.
Interesting find you get three, 3v Lithium Sulfur batteries for a 12v item. I swapped out out defibrillator battery packs in some of our portable units. I found 4 D sized Lithium Sulfur batteries in each. Worthless for most uses as they use a wire from either end soldered to the board. Looks like a giant capacitor. So our department is using defibrillators using 4 D cells and theirs uses 3 CR2’s. That’s a huge capacity difference.
Just to keep it real, I thought I would post a couple of failures.
Today I found these 3 packs. 2 old discontinued Ryobi 24V packs and a new Echo 58V pack.
Turns out the Ryobi on the right had been through some sort of catastrophe and had melted parts inside. All cells were zero and there is evidence at the terminals of what happened on top of the pack.
The other Ryobi looks like it was used just a couple of times and it is on my charger waiting to be tested.
The 58V Echo is definitely brand new, never used.
ImA4 had already found one of the Echos, he said it looked new and it seems that the cells are in perfect condition, He found a 4A pack that contained 28 2A cells. I found the 2A version and it only had 14 cells. My pack looked brand new, but all cells were at zero. All I could do is strip the pack of its’ cells to get at the only thing left of use to me.
Cell holders!
And after a lot of work stripping everything out, I ended up with this. Enough to hold 56 cells!
Sure you “could”…. but where’s the fun in that. LOL …. …
Plus, and this would be very unlikely; though not impossible: wood might contain just enough moisture to make the part of the battery contacting it do “funny things”.
^
Agreed. Breaking down power tool packs is dangerous and fun enough to be addicting. Plus, there are usually nice quality components in them for folks that tinker with SMD electronics.
As dcho said, I was fortunate enough to get one of those packs with 28 like new cells. I can testify that the cell holders are very nice quality. Really holds the cells nicely with just the right amount of pressure. I liked mine so much that I ground off the tabs that stick out to the sides. They have been designated to hold my best high drain cells.
I used to hit the neighborhood CVSes, Duane Reades, etc., anyplace that sold disposable cameras, and ask for those with flashes. When pressed, I’d say I was teaching a basic-electronics course, and wanted to give the students a circuit (the flash) that was pretty simple, yet interesting, to dissect.
Mostly worked. Some people (usually younger girls who couldn’t care less, as it wasn’t their property) would cheerfully fish out a dozen or two, load ’em up into shopping bags, and send me on my way. The younger guys would be all like, “Naw, you gotta talk to my manager, I don’t wanna get in trouble”. The managers would be the ones who would give me a hard time, saying the store gets “rebates” or somesuch, which I kinda doubted.
So there was more’n one reason to go when the teenyboppers were there.
Nice, though. Flashtube, HV circuit, HV cap, and a lightly-used AA, in each one. Plus various gears, optics, etc., to play with. Don’t think I had to buy an AA cell in years…
And parallelled caps when charged up make a nifty spot-welder! Clear “whiskers” from worn NiCd cells. Etc.
I forgot to report back on the condition of the purple celled “hoverboard” pack.
I charged the pack up and drained it into 2 - 3 ohm power resisters in series. After doing this I estimated that pack to have a capacity of “4108 mAh” or about the rated 4Ah. It could be that it is a brand new pack. Maybe thrown in the bin by someone who just didn’t want to risk using a hoverboard after seeing them in the news.
Apart from the wimpy weld joints, the pack seems to be well made. The included Chinese cells seem to perform well, how safe those individual cells are on there own is unknown.
Also of the last 3 packs I reported on here,
The pack on the left, a Ryobi 24V pack, charged up and is working perfrectly. It looks as though it is very lightly used and originally was rated at 2.6Ah. I tested it and estimate that this pack is good for 2.4Ah. My theory on this one is that the person that owned it threw it away because the tool it goes to broke. Ryobi has discontinued their 24V line, so that person had no other options other than ditch it.
I have a working 24V Ryobi weed wacker and can put this pack to good use
Regularly coming across big packs these days. I got excited when I pulled the 56v pack on the right. Ended up only having 14 Sanyo UR18650RX's at 3.67 - 3.68v. This is the second big pack I have found that was labeled at a voltage greater than nominal voltage. In the past, such a pack would be labeled 50v.
Very well built pack. 2Ah cells dated S37 (September 2014). Haven't tested yet, but the pack looks unused. No dust, dirt, or scratches to be found, even in the corners and contacts. Maybe it was a display model being disposed of by the store. Maybe HD is closing out a product or product line.
that brown glue might be the cause of self discharge.
that curse has been known over 40 years.a built in failure point.
peeling a bunch out of a uniden hr2510 right now….
