explosion when charging li-ion cell, Universal Smart charger set on wrong voltage

[LuxLuthor]

I´m feeling pretty much at ease also Lux, after seeing the 4s3p setup and the PCB board, only I think the charge rate is more like .3C give the three parallel sets.

I went back and did some research to better explain the .3C charge rate above given I am not an expert in the matter but this is what I´ve more or less found, someone correct me if I´m wrong please.

The BB has three strings of 4 in series 18650 2200 ma cells

Voltage= 4.2V x 4 cells = 16.8 Volts and Current= 2.2 amps (cells in series do not add current but voltage

Ok, so now we have three of these strings and so the charger does see an individual voltage of 16.8 V, but now we add the currents of the three strings

2.2 A x 3 = 6.6A

And hence the charge rate is more or less 0.3 C

And so that configuration allows the BB to hold a voltage for the ballast and increase the runtime. If the protection circuit built in the pack is good, it should monitor each cell connected in series and each of the three strings as well.

Yeah, that 0.3C sound more accurate now that I read your post. I don't see how it could monitor each cell in each series of 4 cells without individual cell taps though.

 

[Sigman]

(chasm22 - I sent you a PM.)

ARrrrrggghhhh - getting those darned "Server busy..." messages!! (Seems things have been running fine since the last "tune-up"...today "someone" must be doing "something" :thinking: )...

Ok, to the point:

Folks - this is indeed a SERIOUS subject, one which could/would/should benefit all of us in the realm of SAFETY.

We would really APPRECIATE it if everyone could calm down a little, think about the subject and post content - then reply ON TOPIC. Looks like a few "stones" are being thrown at each other here & there. While they appear to be small pebbles...we don't want larger rocks to be picked up for the next toss, eh?

Sorry about my weak analogies...but seriously, we don't to shut this down because we aren't concentrating on "attack the post and not the poster". I even hate to use the word "attack".

Please? Thank you!!

 

[Sigman]

OK - I've tried to calm things down here. I've got a life and need to go take care of some things. I'm closing this thread for now...soft deleting chasm22's baiting post above for review.

 

[Empath]

After considering your actions, Chasm22, it's been decided to suspend your posting privileges for a period of 7 days. Please read CPF's rules, and particularly #4, the primary one in which you're in violation.

 

[Sigman]

IF we are all done throwing rocks at each other now...we'll open this back up for respectful discussion & important safety related content?