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why do all batteries require different charging? Answered

i mean like the difference between nimh, lead-acid, lithium-ion, and recently even alkaline.
how do they each charge, and why is there a danger of exploding batteries (like lithium-ion) when charged the wrong way.
is it like charging in fast on/off cycles, high volt low amp (or the other way around) or messing with anything else?

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steveastrouk

Best Answer 8 years ago

The chemistry underlying each of the batteries you mention is radically different, so the charging cycle you need for them is also radically different, and particularly important the detection of FULL is different. If you don't detect "full" properly in a LI-po battery, it can overheat and explode, if you discharge it too fast it can overheat, and explode.

Do some Googling.

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godofalsteveastrouk

Answer 8 years ago

i knew that already, what i should have been more clear about, is that i wanted to know about the different ways to charge batteries. (like said in the last couple of lines...)
sry for not being clear ;)

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steveastroukgodofal

Answer 8 years ago

The key ways are at a constant current, or at a constant voltage (with a current limit).  You don't usually modulate the charging current.

Lead acids are usually charged at constant voltage,
Nimh and Nicad at constant current.

The RATE you charge at is pretty critical to battery life - fast charging ages everything but some LiPo and Lead acids for example much more  quickly.

Steve


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steveastroukgodofal

Answer 8 years ago

Lithium don't suffer from memory effects, but they still have a lifetime.

Steve

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godofalsteveastrouk

Answer 8 years ago

i mean, how to charge them, i've seen (youtube) that they explode when u just charge them with the same voltage as theyr specified for...

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steveastroukgodofal

Answer 8 years ago

That's right, if they don't have the right protection they can go into thermal runaway. You HAVE to terminate charging at something like 4.30 Volts per cell OR lithium metal begins to plate out, and the cathode releases oxygen - yummy.

I would buy a lithium charger circuit "off the shelf" (Maxim, Linear Technology, Analog Devices etc etc) rather than roll my own.

Steve