What battery chem did they sell me?

Hi guys, after much agony I finally bought a 48v 10ah battery, the "frog" case model from conhis. http://conhismotor.com/ProductShow.asp?id=210
When it arrived I was shocked that it weighed so little 3,4kg (7.5lb) so I opened it up. It is supposed to be 5p13s, and I thought it to be a Li-Ion NiCoMn chemistry... but, at this weight, it has to be lipo right? Haven't checked how many amp hours it actually holds.

I opened the case, and it's a pack of greyish pouches with a a bms bundled in with heatshrunk plastic, you cant see much unless you cut the plastic...

Whats the final voltage on the charge, and how many cells in series, that will definitely help, may not be definite depending on voltage though.

It's using Li-Ion NiCoMn pouches. Pouches weight less that cylindical cells.

You basically have one of these but the 10 AH version.

Thanks amigafan, that is most likely it! Seems to be the right weight etc. Kinda happy if they are not lipo, I live in an apartment and dont really have a safe place to charge them... btw, It's supposed to be 13s, but it's hard to see. The charger is supposed to cut off at 54.6v per it's markings, but when I measure I get 52.5v. Not sure what to make of that, it could be my multimeter that's off a bit I hope? Guess the only way to know for sure how many amp hours its holding would be to do a discharge test with a known load. Want to put some cycles on it first before bringing it all the way down to lvc...

As long as it performs well, it seems like a nice pack - lightweight, not too expensive, good mounting solution. Sure, you dont want to pull 1000+ watts out of it, but with my ecrazyman controller 48v/500w it should be a good match.

Btw, lipo is not a chemistry, it is a cell form factor and it refers to a pouch style cell.. just FYI.

The potentially 'splodey chemistry you're referring to when you say 'lipo' is lithium cobalt, or li-co.

Yeah, chemistry very similar to the one from BMSBattery. It's LiMN2O4 battery.

I've the 36V version that weight 3 kg.

However, it has lost 33% of its total capacity in 5 months. Not sure if it's the weather (around 11C),but that's annoying.

Hopefully at least some of that capacity will return when temps are more warm. I lose about 20% capacity on pingbattery if the weather is very cold. That improves if you insulate it.

Didn't know that about lipo/lico, thanks. Don't like the sound of that capacity reduction... hmm, I guess time will tell, I hope mine holds up OK. loving the power to weight rato!

lipo is lithium polymer. the cathode is an organic structure that holds the ions.

lifepo4 is lithium iron phosphate, the cathodic structure is a spinel, a crystalline structure that retains its physical strength when depleted of lithium ions which it stores in the voids inside the crystal. it is not the same as lipo.

limn2o4 is lithium manganese oxide, a crystalline structure which holds the lithium ions when they are stored in the cathode. again, not the same as lipo.

lipo is an organic polymer which will not hold the oxygen atoms from the chemical reaction when heated. lifepo4 has the oxygen locked into a structure which does not release the oxygen until it is heated to over 600 degrees C. this is why lifepo4 is safe when over charged and lipo is not.

Thanks Dnmun

dnmun said:

lipo is lithium polymer. the cathode is an organic structure that holds the ions.

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Both anode and cathode hold ions...

dnmun said:

lifepo4 is lithium iron phosphate, the cathodic structure is a spinel, a crystalline structure that retains its physical strength when depleted of lithium ions which it stores in the voids inside the crystal. it is not the same as lipo.

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No. Lithium Iron cathodes are not spinel, they are olivine structures. Manganese chemistries, and a couple others (that aren't used because they don't make sense) have spinel structures. They also use a polymer seperator containing the electrolyte, the very same polyethyleneoxide or polyvinylidene difluoride film as RC LiCoO2 LiPo and NMC LiPo etc.

dnmun said:

limn2o4 is lithium manganese oxide, a crystalline structure which holds the lithium ions when they are stored in the cathode. again, not the same as lipo.

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All cathode material is crystalline (unless I'm forgetting one?)... Manganese oxide is arranged in a spinel formation. They also almost always use a polymer seperator containing the electrolyte.

dnmun said:

lipo is an organic polymer which will not hold the oxygen atoms from the chemical reaction when heated. lifepo4 has the oxygen locked into a structure which does not release the oxygen until it is heated to over 600 degrees C. this is why lifepo4 is safe when over charged and lipo is not.

Click to expand...

LiFePO4 burns and explodes impressively just like everything else that stores energy if you do enough of the wrong thing to it. LiFePO4 just has a much stronger bond to break before liberating the O2. A123/headways/thundersag cells blow up nicely with enough over-charge, just like everything else that you cause to take in more energy than it's able to shed after it's saturated it's ability to store energy.