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  • Charging Li-Ion pack.....

    So I quickly put together an Ammo Can BT radio for a buddy of mine and want it to charge off a power supply when it is off.

    Can I simply use a 19V 3.4A power supply to charge the pack (cells are protected) or must I do something else?

    Thanks!
    Builds - C-Killa - Speedsters - LithMTM - Talking Sticks - Pocket Rockets - Khanspires - Dayton RS Center - RS225/28A - Kairos - Adelphos - SEOS TD12X - Dayton 8 - Needles - 871S - eD6c - Overnight Sensations - Tritrix (ported) - Lineup F4 - Stentorians - The Cheapies - Tub Thumpers - Barbells - Tuba HT - Numerous subwoofers - probably missing a few...... :p

  • #2
    Oh, 4SP1 typical battery holder with these cells.....

    https://www.amazon.com/EBL-3000mAh-R...ds=EBL+lithium
    Builds - C-Killa - Speedsters - LithMTM - Talking Sticks - Pocket Rockets - Khanspires - Dayton RS Center - RS225/28A - Kairos - Adelphos - SEOS TD12X - Dayton 8 - Needles - 871S - eD6c - Overnight Sensations - Tritrix (ported) - Lineup F4 - Stentorians - The Cheapies - Tub Thumpers - Barbells - Tuba HT - Numerous subwoofers - probably missing a few...... :p

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    • #3
      Originally posted by joeybutts View Post
      So I quickly put together an Ammo Can BT radio for a buddy of mine and want it to charge off a power supply when it is off.

      Can I simply use a 19V 3.4A power supply to charge the pack (cells are protected) or must I do something else?

      Thanks!
      The answer is absolutely NOT. There are all sorts of things wrong with this... First off, lithium cells require a constant current/constant voltage charge profile, meaning you charge them with constant current up to the max voltage, and then hold constant voltage while the current tapers off. A proper charger will also terminate the charge, typically when the current tapers off to 10% off the fast charge rate. Leaving Lithium cells on a "float" charge is a very bad idea. You also need balancing. With out a balancing charger or BMS (battery management system) board, you are likely to overcharge a single cell (or multiple cells), which can result in fire. Next, I didn't look up the details of those cells, but 3.4 Amps is a fairly aggressive charge rate, IMO. The cells might be OK with that charge rate, but you're likely reducing the overall life of the cells. Another thing a BMS takes care of is low-voltage cutoff. Over discharging lithium cells can be very dangerous when you go to recharge the pack. Also, a true charger for lithium cells will take a look at pack voltage and if the pack is too low at the beginning of the charge cycle, will provide a lower current pre-charge cycle until the cell voltages reach safe levels for full charge current.

      Lithium batteries and chargers are a much more complex system than the NiCd/NiMH/Pb batteries of the past, and most people don't realize this. Also, Lithium batteries tend to fail in much more catastrophic ways than NiCd/NiMH/Pb batteries.

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      • #4
        Just a peek. The Dayton KAB 18650 board holds and balance charges 3 cells, power supply needed.

        Battery balancing - Wikipedia

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        • #5
          Thanks guys! I thought the chip in each of the cells regulated charging individually....

          DJG, I would like to use that but want a higher voltage....
          Builds - C-Killa - Speedsters - LithMTM - Talking Sticks - Pocket Rockets - Khanspires - Dayton RS Center - RS225/28A - Kairos - Adelphos - SEOS TD12X - Dayton 8 - Needles - 871S - eD6c - Overnight Sensations - Tritrix (ported) - Lineup F4 - Stentorians - The Cheapies - Tub Thumpers - Barbells - Tuba HT - Numerous subwoofers - probably missing a few...... :p

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          • #6
            R/C hobby uses Li poly packs with any number of cells and balance chargers, but generally require the removal of the pack from the device. If you can remove the 18650 cells from the device and put them in a dedicated charger you can use however many you need. Installing 4 or more 18650 cells in a device and using a simple plug in charger doesn't work.

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            • #7
              ahhhhhh. OK. I'll let him know and move on from there.....

              Thanks so much!
              Builds - C-Killa - Speedsters - LithMTM - Talking Sticks - Pocket Rockets - Khanspires - Dayton RS Center - RS225/28A - Kairos - Adelphos - SEOS TD12X - Dayton 8 - Needles - 871S - eD6c - Overnight Sensations - Tritrix (ported) - Lineup F4 - Stentorians - The Cheapies - Tub Thumpers - Barbells - Tuba HT - Numerous subwoofers - probably missing a few...... :p

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              • #8
                Hope PE doesn't mind. I buy stuff from here often.

                Battery Chargers

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                • #9
                  If you haven't bought the "protected cells" yet, Use the new Sure Battery Management Module (BMM), not the one for the KAB amps. The KAB BMM has over and under voltage protection as well as max discharge current protection, but it does not have charge current/voltage management (remember the Hover board fires?). The charge management function was on the KAB Amp modules.

                  The new Sure BMM has all the functions needed to manage unprotected 18650 cells. You can use any 15 V to 24 V PS. They are 3S modules nominally 12 V. If you want to use two Sure BMMs for 24 V battery operation, see this thread.
                  '
                  As far as Li-ion 18650 battery ratings, anything over 3600 maH is BS. The highest density cells are the Panasonic 18650 at 3,400 maH. Gordy likes the Samsung cells of slightly less capacity. And buy from a reputable dealer. Vendors on eBay and what not will sell cells with bogus spec's, counterfeit wrappers, and cells that didn't pass QC. And the Li-Ion battery technology is very sensitive. You don't want to start a fire.

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                  • #10
                    Thanks Mike! Checking and checking. Would be great to make it plug and play for him and others....
                    Builds - C-Killa - Speedsters - LithMTM - Talking Sticks - Pocket Rockets - Khanspires - Dayton RS Center - RS225/28A - Kairos - Adelphos - SEOS TD12X - Dayton 8 - Needles - 871S - eD6c - Overnight Sensations - Tritrix (ported) - Lineup F4 - Stentorians - The Cheapies - Tub Thumpers - Barbells - Tuba HT - Numerous subwoofers - probably missing a few...... :p

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