Chinese 12V 50000mAh battery pack teardown (18650 lithium ion cells) 

No to jest nas dwóch ;}

The BMS will protect the batteries from overcharge. The load you are feeding will probably get quite upset with the noise that comes off the really badly made switched mode power supply plug that comes with the battery pack. Should the load pull more current than the switched mode power supply can supply, current will be drawn from the battery too, until the battery drops below the BMS's low voltage level, at which point it will shut off. Then your load will be receiving whatever the switched mode power supply can provide.

3S2P cell mAhxP count

I bought that battery pack from "Aleaivy battery 2 store" www.aliexpress.com/store/911706446

There are also fake 18650s on eBay's too! I've found that online vape shops tend to pride themselves in battery life so have decent QA over their battery suppliers, so they are a good source for decent batteries.

They are shameless!! I wonder if any of those 8 parallel banks were filled with sand? The most you could get with 8 parallel would be 3500mAh * 8 = 28Ah, but I'd be willing to bet most of those cells are low capacity

I've found that the best way to get proper 18650 Lithium ion cells is to buy them from a reputable vaping products dealer, then get the charging / protection circuit as a module from AliExpress. You'll pay £2-£4 per Lithium ion cell but they will be high quality.

No worries: simply weigh the battery pack the moment you get it. If it weighs less than 5.4kg (48V * 30Ah / 265Wh/kg = 5.4kg), then send it back as "goods not as described". Just check how it was advertised. If they stated "30 amp", then they might be referring to peak current output capability rather than capacity. If "30 amp-hours" then it's capacity.

@@MichaelBrooksDr it's actually the same one in this video and it says capcity 30 amps I want to parallel with my other 48v battery for ninebot max g30

​@@jonathancifuentes7442 Jeez they really are taking the mickey now. Are there only 6 Lithium cells in there? Or have they at least added another 6 to create 6s2p so you get your 48V? If you are looking to parallel with another pack, make sure the second pack has similar characteristics (actual capacity, voltage) and has its own charge/discharge controller.

Been there, done that! ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-BD6LDkETpm0.html

The trick is says 50 thousand mah, a ma is 1,000 so it true , but you might think it means 50 k ah than it not true, but these are kids toy car 12 volt battery so their just cheap computer AA cell their not more than 15 bucks

Yep! Any tips on how to identify an honest battery on AliExpress?!

@@MichaelBrooksDr Look on reviews with tests. Don't buy buy branded batteries with big Samsung and don't buy unreal capacity battery's. Some relative good brands are: Liitokala or Varicore for li-ion and HRB for LiPo. And buy from the "official" stores :)

Eh? The battery quotes its capacity in milliamp-hours, which is current * time. In your comment you are multiplying current * time by voltage, which gives you capacity in milliwatt-hours. But the battery quite clearly states "mAh". A few lines below it says the same thing again "Voltage/Capcity: 12V/50Ah" [sic] Power = current * voltage Power * time = current * time * voltage (mWh = mAh * V) Is your argument that the label is a typo and that the Chinese manufacturer really meant "50000mWh" and "12V/50Wh"?

@@MichaelBrooksDr Chinese Math is out of world. It 50000 means 50000 . afterthat all are valueless letters . wow its the way China calculates its GDP and what not? ha ha ha.Sorry see my answer as light humour .

I've been using the cells to run my bicycle lights. Judging by the runtime I'd say it's even less!

@MichaelBrooksDr well lights are a constant draw at whatever amp rating so runtime is a factor of what hour

@@joeKisonue yes, watt hour is amp hour * voltage. (Wh = VAh). Both are therefore a measure of total capacity of a battery.

this is correct - undersize Chinese math - this battery 50 000 /12 = 4 Ah - simple :)