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Old 08-24-2016, 09:51 AM
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itsid itsid is offline
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Quote:
Originally Posted by BirdFanatic View Post
I'll play it safe no more tea pot lol I'll throw the **** thing outside as if it where a grenade and someone pulled the pin.Making sure it's not around anyone or anything that can catch fire .
That's what I wanted to hear
play safe... don't take a risk if a cell get's uncomfortably hot.. act quick.. when in doubt: RUN!

Quote:
Originally Posted by BirdFanatic View Post
Lipos have a soft case that are very vulnerable to being punctured.
not necessarily!
Quote:
Originally Posted by BirdFanatic View Post
So I have 5 18650 in parallel let's say I have written there mah on them using the smart charger /discharger I group them and add the total mah of the 5 there are 4 rows of 5 parallel batteries .Then I add up the other 4 and make there mah as close as possible to the 1st group .The smart charger helps me weed out the bad batteries if they don't reach over a certain mah I don't use them for my pack .I do not throw them away either I use them for flashlight batteries. I wouldn't want to use a cell that should have 2200mah brand new but has 800 mah a cell with 1700 mah is good .
What now you said 4p 5s.. now it's 5p 4s...

typo?

Anyways.. that's the wrong way around!

you want to stack similar cells in series,
and pack these in parallel.

Not the other way around.

in series all cells try to hold a similar charge (total charge is set by the weakest cell)
in parallel charges add up (total charge of the individual stacks of cells in series)
And while this too SHOULD be stacks of similar charges..
in parallel it's the stacks resistance determining the amount of charge the stack will hold.
it's trying to self level ... (It cannot too well though... that's where all the microprocessing comes in)
So a stack can still overheat (hence I asked you to add thermal fuses to each stack)

BUT it's the safer approach since similar cells will heat up more evenly,
and a single thermal fuse (at the right tempsetting of course) is more likely to protect all cells in a stack even if it's only touching two or maybe three cells.

'sid
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