dogman dan said:
Amberwolf wants to see a test of my ammo box storage. I keep lipo in ammo boxes, with some vent holes on one side.
Actually, I'm wanting to see a test of my on-bike ammocan type of pack (which cna also be used for storage). But it amounts to the same thing.
I've got 14s2P of RC LiPo in a 7.62 can with the lid's edges slightly flared out and a slot cut at the "deepest" part of the flare, for wires to go in and gases to come out, but can't come straight out becuase of the flare. On my bike that'd essentially point gases downward, with the pack mounted under the righthand part of teh seat on the cargo frame.
I've got 14s1P of EIG NMC in a 50cal can, with the case corner nearest the hinge on one end notched for wires and gases, but no flare on it's lid so they'd come straight out. On my bike that's pointed straight forward, pack is essentially under the seat inside the framework.
I've got an EM3EV A123 pack in another 50cal can, modified the same way. When mounted on the bike it goes the same place as the 7.62 can, so it'd vent forward too. (unfortunately that would be into the back of my right leg. It could be mounted in reverse but I'd need to make a longer extension cable to hook it up to the bike's power input.)
What I do not have, is anywhere near a safe and legal place to set off the test. We need the Mythbusters, with their access to a nice old quarry, for such a test.
I *really* don't think it could explode, even with covers dogged down, if there is a vent. But if it did, it could be bad if you were in an area with people and stuff.
If you could dig a pit in the yard, and sandbag around it with the fill coming out of the hole, you could use that for the test.
For myself, I am willing to do the test in the open in my own backyard, with the dogs in the house--if I had enough bad RC LiPo to do it with--basicallly enough to fill the can. I probably will at some point, when the cells in my 7.62 can pack stop being worth using, but they still have mroe than enough capacity to keep going for a while, at least.
The thing I'd like to know is if the pack will actually burn and keep burning in there spewing flame, or if it will be contained in the can and only vent hot gas, with no oxygen input possible except from whatever is already in chemicals inside the pack.
I expect the results would be different with different chemistries, but with RC LiPo being the worst possible one I know of, it'd be the ideal one to test with.
I'd also like to instrument it with voltage and current and temperature and pressure sensors, but I think the best I will realistically be able to do is run a balance lead out for some of the cells to the already-problematic MaxPro I have, which will track 5 cells (of the 6 it's made for), and use a wattmeter on the main connection from pack to charger (probably my big Sorenson+serverPSU combo, since that'll do about 67V @ 25-35A, or more A at less V, since I don't have a 3-phase input to use with the Sorenson), plus a BBQ thermometer as close to the center of the pack mass as I can place it.
FWIW, I have the RC LiPo ammocan pack inside another metal box, since I found the packs starting to age and puff. That box is an old aluminum USNavy RF generator test equipment carry box, fairly heavy duty, and is unlikely to let the fire out if something does happen (even if the ammocan somehow pops apart from pressure). It's not fully dogged down either, just enough to ensure any popping that happens inside it isn't going to throw the lid into the air and let bits of flaming whatever fly off and start fires, since ATM I don't have a good place outside to keep usable batteries. (I have an old oven but it's in direct sun in the morning all year round right now, and havent' worked out where I can put it away from the house that's *not* in direct sun for significant time sometime in the day).
