Maybe thereās a seam in the black section at the blue location that could be pried open with a putty knife? Or maybe you could drill in through the side of the silver case at the red location to try and pry the black box out with a flat head screwdriver?
Hey @xsynatic can we get @Solid bumped up a trust level or something? He canāt post the next step in his process
I canāt sorryā¦ Aināt got no powers to do it. Only the real Mods can, though not sure if they do it since all of had to live with the limitations. U gotta ask them, sorry.
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OK, Iām back from the purgatory of new account posting timers.
I found screws in the metal casing that had the black cage around the battery secured to the metal casing. A total of 5 screws on the short faces of the battery that I had to unscrew, after that I just pried it up using a Ifixit tool and it popped out ok, no damage. The paper is just a cover for what Im guessing is the BMS for this one. Its attached to the black cage with screws on it with another piece of paper protecting a vital chip on the board. I havenāt unscrewed them yet, but I did pop the black cage on a half seam where the screw mounts were. I can open the thing but Iām still working cautiously with thing. I have a fire extinguisher rated for lithium fires in my vicinity at all times when messing with this lmao
Here are the other pics:
As always, I appreciate any help and comments. This community is so cool 
hopefully my build helps someone after me lol
OK team,
I managed to get the black cage off by using a pair of flat sided snippers and cutting sections around the wires so it could slide out. From that point it was a matter off prying off cage which is attached to the inner battery with some very strong adhesive. Then after that, on the long facing side of the batty is the flaps for the interior casing shielding the actual lithium pouches, which signals the farthest I can go. Thereās another board on top of a foam pad, I have no idea what this is. Now that I have made it this far, I would definitely like some direction and what i should do now.
How would I test it now to see if it viable for use? What should I calculate or look out for?
Hereās the Pics |
the case flap actually twisted off 
thanks for any help guys 
Hihi, a couple of things here that are hopefully not too all over the place
Very good!
Yup, looks very much like the BMS. That second board is likely just a sort of interface, thereās probably no electronics of note on it it just connects to the positive and negative tabs of each pouch and routes them to that wide connector for the BMS.
Thatās interesting that they used pouches rather than round cells. FYI the quick and dirty way to refer to these type of cells is as LiPos or lithium polymer, and round cells as either their size designation (18650 cells are 18mm in diameter and 65mm in length, 21700 are 21mm D and 70mm L) or as lithium ion. The issue is that the names are inaccurate or unhelpful on a technical level but the convention is sort of set now. For eskate you can generally get better energy density with round cells (more total capacity and range in a given cost and sometimes weight), and the cells are a little more tolerant of abuse. With lipos you generally get higher power output (accelerate harder, higher top speed etc) at the cost of some capacity, sometimes cycle life (how many times they can be charged and discharged before needing to be binned) and a slightly more violent reaction if you mess them up. Lipos really really really do not like to be stabbed or punctured.
The differences exist, but arenāt make or break. There are some prebuilt eskate boards that use lipos mainly to be very thin and hide the battery inside a deck, and quite a few DIY boards, but the majority are round cells. Overall it looks like a surprisingly well built pack, lipos tend to benefit from some compression and they usually need structural support so the plastic frame, insulation, silicone on solder bonds, and metal housing are all good signs
For what to do next, this is another safety concern so do be careful. To assess the rough state that the pack is in (really itās more to see if itās already ruled out, it doesnāt guarantee safety) you need to check the individual voltages of the pouches. If theyāre outside of their safe range they almost definitely need to be disposed of, and if theyāre significantly out of balance the BMS is likely cooked and some or all of the pack may be too. Balance here meaning that the cells (pouches) are at a similar level of charge, maintaining this balance is one of the main aims of the BMS, because if theyāre out of balance then one cell may become over charged or over discharged while the others continue to run or charge, and thatās a recipe for a fire.
To do this, you need a voltmeter where the negative lead is attached to the battery negative (make sure itās the negative of the actual battery cells directly, and not the negative after itās already been fed through the BMS). The positive lead is then going to probe the voltages of each cell individually. IMO the best way to do this is hold the negative lead with one hand to the pack, and use the positive probe on the balance connector. Donāt probe both the positive and negative from the balance connector, because the connections are around 2mm apart and if your hand slips the probes will short out two or more cells. Use a negative far away from the balance connector, and be careful with your probes.
Record each voltage as you go, hopefully they will be evenly space voltages, something like 0V, 3.7V, 7.4V, 11.1V, etc because that gives nice even spacing. 11.1 - 7.4 = 3.7, and 7.4 - 3.7 = 3.7 as well, youāre all good. If instead it reads like
- 0,
- 3.7,
- 7.4,
- 11.1,
- 12.2,
- 15.9
then youāve got a big problem between pins 4 and 5, 12.2 - 11.1 = 1.1, so that cell is way below its safe voltage and IMO thereās no way for a non-expert to salvage a pack like this. The difference between cells might be 4.2, meaning theyāre fully charged, or 3.7 meaning theyāre around storage voltage, or somewhere in the middle, but consistency is what youāre looking for. As above, it doesnāt mean the pack is great (the cells could be really old and when you draw a big current theyāll just crap out) it just means the cells arenāt already goosed in that really obvious way
Hopefully that was follow-able, but it likely will be daunting. Thatās probably a good sign. Please if youāre not sure do not try poking around blindly, your initial instinct of having a fire extinguisher at the ready, going slowly, and assuming you shouldnāt go any further are good. Also I think best practice is to do this somewhere that is either outdoors or can quickly be outdoors, like a garage, and away from anything soft or flammable
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Ok, thanks for the info
Iām definitely gonna give what you said a try. I only did the breakdown indoors because itās closer to my PC but I do have a spot on my balcony where I can do this. I do have an Extinguisher and also a bin full of sand because I heard that itās good to smother a reaction right away if possible. If possible I would like to get a pizza peel to work on so in case of a fire I can just yeet it into the sand. 
But any other safety tips are appreciated
I think my biggest issue is figuring out where to place the probes on it to get an accurate read. I actually use to be an apprentice electrician but didnāt have a passion for it so I didnāt really learn much about this stuff. Which is why I say Iām a complete noob, all I really learned was how to use power tools effectively LMAO
so any beginners donāt feel bad about learning and taking a leap, just stay humble Back to my original point, I would need to know what spot on the thing to get a reading so if you could point out where then I could do it. Also what setting should I set on the meter, once again I have used this tool before but have actually no idea how to use it 
Here are some pics |
I got a lot of learning to do lmao
thanks for any help guys
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Cool, quick multimeter rundown but do also Google it a bit yourself
The wheel selects the mode, the modes are separated into blocks of related functions (colour coded region) and specific ranges. Ranges are a bit like zoom on a camera lens, if youāre measuring something really small go to one of the tinier ranges and get lots detail, but you wonāt be able to see big stuff. Zoom out or go to the bigger ranges and you lose some detail but can measure bigger stuff.
V ā is direct current, the grey box on the right. Batteries are DC, as are most power supplies. 200m means that range is for measuring up to 200 millivolt, itās the smallest range. 600 is for up to 600 V. The general guidance is zoom in as much as you can, but not more. So pick the smallest range that youāre not gonna exceed, in this case we will have voltages above 20V but not above 200V, so use 200
V ~ is the same but alternating current, we donāt need that much for eskate. The omega/horseshoe is resistance, youāll need that at some point but not for this. A is for current in Amperes, with DC and AC represented the same. I think yours only has DC current
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So before you dive in to poking this thing, practice on other stuff. Iād recommend small batteries like AA/AAA or watch batteries just to get a feel for using the probes and what to expect on the screen, as well as some circuit board that doesnāt have the chance to kill you. Open up a TV remote or something thatās battery powered and small, and pull up some YouTube videos on using a multimeter. IMO youāre better off taking quite a bit of time here because if you havenāt used a meter at all before youāre going to make a lot of quite simple mistakes and those shouldnāt be on something that can start a fire
For where to take a reading on the battery, black is negative red is positive by convention. Pick a big black wire directly on the cells, thatās battery negative, put your negative probe there. The wide connector on the second board you encountered, the one I said was likely just an interface, thatās your balance connector. Unplug the balance lead from it, and look at the pins. These pins give you voltage readings from the cells directly.
Also, most people here would be much more conservative than me with people who theyāre not sure are safe to follow this kind of thing, so Iām gonna be annoying and reemphasize the point of please donāt get yourself killed
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Cool thanks for all the info on what I need to do, youāre right though, I do need to do some research on how to use this multimeter and how to test circuits. Iām a youtube goblin, so I can search up and learn it eventually. Thanks for the pointers tho I will take the upmost caution to no get myself killed lmao
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I have some of those same packs I got for $5 but they were completely shot.
The empty cases fit two rows of 5 18650 cells.
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Yeah even if these packs are trash the cases are really sturdy though, definitely could find another use for them or put in new packs
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I meant to model them and make some cells holders. Might be cool for a sturdy powerbank.
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Hey esk8 people,
It has been 2 weeks and I have just been swamped in the personal life stuff, same old same old. @mr.shiteside, I read your comments like twice over the 2 weeks and Iām still confused on where to measure the voltages on this thing, I peeled the paper on the board resting on top of the LiPos. If possible, I would be easier is you pointed out on here what I should measure. Hereās some pics of what Iām talking about.
As always, any help is appreciated.
