CrazyEngineers
CrazyEngineers

  • charging of batteries

    pratik20990

    Member

    Updated: Oct 26, 2024
    Views: 1.0K
    I have four 3.7V 1400mAh Li-ion batteries that are to be connected in series so as to get resultant voltage of 14.8V and 1400mAH current rating.

    My problem is that how to recharge them as I don't have any charger for them. What I know is that, If I use an external power source of say 16V for the batteries and connect positive of power source to positive of batteries and negative of power source to negative of batteries which are connected in series then it will charge them. But I am confused about the current rating of the power supply to be used. The one I have has current rating of 2A and the batteries will have current rating of 1400mA.

    Please suggest me will this will work or not. Please reply asap its urgent.
    0
    Replies
Howdy guest!
Dear guest, you must be logged-in to participate on CrazyEngineers. We would love to have you as a member of our community. Consider creating an account or login.
Replies

  • reachrkata

    Member • Feb 18, 2010

    It is dangerous to connect the power supply directly to your battery. The current may be so high that the battery may overheat and get destroyed.
    Check the datasheets of the battery. There will be a maximum charging current specified. Using some circuit (like constant current sources) ensure that this current is not exceeded.

    -Karthik
    Are you sure? This action cannot be undone.
    Cancel

  • Codex Guides

    Member • Feb 24, 2010

    I would not recommend trying to charge lithium-based batteries without a charging controller. The batteries have a good chance of exploding or venting toxic fumes. As Karthik said, it's possible to overheat the batteries. Lithium-ion batteries may explode; lithium-polymer batteries may catch fire or vent toxic fumes. I've seen both, so it can and does happen.

    The best option is to pick up an inexpensive lithium-ion charge controller IC and use that to moderate the charge voltage/current to the battery or battery pack.

    Having said that, if you're careful, you can do it. But the applied charging voltage and current must be in the right ranges. If the voltage or current is too low, you won't charge; if it's too high, you will damage the batteries (and maybe yourself).

    Check out this link for more information: #-Link-Snipped-#

    What you're doing could also be done with nickel-cadmium, nickel-metal-hydride, or lead-acid cells, IF you are careful and don't try and charge too fast. They are slightly less picky than lithium-based cells, but you can still cause damage.

    Whatever you do, don't try and charge them FAST this way! You should be thinking about a two-to-eight hour charge rate, not a 15-to-60 minute rate.

    - CG
    #-Link-Snipped-#
    Are you sure? This action cannot be undone.
    Cancel

  • KAPILBEC

    Member • Feb 26, 2010

    I DON'T THINK THAT THE CAPACITY OF THE BATTERY LL REMAIN SAME THE TOTAL CAPACITY OF BATTERY LL BE 5600mH
    Are you sure? This action cannot be undone.
    Cancel

  • reachrkata

    Member • Feb 26, 2010

    Nope, Batteries in series retain the Ah rating, and batteries in parallel retain the voltage rating.

    - Karthik
    😁
    Are you sure? This action cannot be undone.
    Cancel

  • Ashraf HZ

    Member • Feb 27, 2010

    As Codex said, it would be a lot wiser to invest in a lithium battery charge controller. Not only will you need to moderate the current, you'll need to make sure each cell is charged somewhat equally if they are connected to each other.
    Are you sure? This action cannot be undone.
    Cancel
Home Channels Search Login Register