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Lithium Ion Charging Voltage

  1. Feb 27, 2016 #1
    Hi, I have built a large, lithium ion battery bank, so that I may power some of my projects from battery. The bank is 10,000 milliamp hours at 16.9 volts, and was wondering the following.

    Can I charge my 16.9 volt battery pack with a 12 volt dc source? would It decrease the efficiency? Would my battery pack only charge up to 12 volts?

    Thank you all for your help! it is much appreciated!
  2. jcsd
  3. Feb 27, 2016 #2


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    If you incorrectly charge a lithium battery you can easily cause a fire. Use a charger designed to charge a 16.9V Li battery pack from a 12V battery do not just connect it directly to a 12V source.
  4. Feb 27, 2016 #3
    what is the reason I can not just directly connect my battery pack to the 12v source?
  5. Feb 27, 2016 #4
    A piece of information that i forgot to include, is that i have a shut off switch for my battery pack, so i cannot overcharge them. The bank is also large enough, that I do not have to worry about charging it at too high of a current, because my power source only puts out 1 amp, which is 10% of its capacity, so I am well within charging current.
  6. Feb 28, 2016 #5


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    Please read something about electronics, and especially how to charge lithium batteries. No way you will connect a 12V source directly to a 16.9V lithium battery twice.

    Lithium batteries require a very precise charging procedure. Especially multi-cell banks.

    You might be able to use 12V to power a charger designed for a 16.9V multi-cell lithium battery, but 1A might be a limitation.
  7. Feb 28, 2016 #6
    so what is the actual reason why I cannot just directly plug it into my 12 volt source? I cannot overcharge them, because I have a shutoff switch, that is designed for that very purpose of shutting off lithium ion charging, as well as I do not pass the input amperage rating of the Lipos.
  8. Feb 28, 2016 #7


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    Thread closed due to safety concerns.
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