FT-818 Ni-MH battery charging.

Discussion in 'QRP Corner' started by W4WVW, May 1, 2020.

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  1. W4WVW

    W4WVW Ham Member QRZ Page

    My FT-818 is usually connected to my 13.8V power supply (Astron RS-35A). Is it ok to leave the Ni-MH battery connected or should it be disconnected/removed once charged?
  2. ON6KE

    ON6KE Ham Member QRZ Page

    No need to remove it OM.
  3. KA9JLM

    KA9JLM Ham Member QRZ Page

    The original wall charger is 12.0V

    So leaving it connected to 13.8V for long periods of time may not be the best idea.

    What does the operating manual say ? It may provide the correct answer.

    You will get mixed answers here on the forum for sure. o_O
  4. W4WVW

    W4WVW Ham Member QRZ Page

    From the manual:
    "The FT-818 may be connected to an external 13.8 Volt DC power source providing at least 3 Amps of continuous-duty current.. The supplied E-DC-6 DC cable may be used for DC connections.

    While connected to an external DC source, if you have installed the supplied SBR-32MH Ni-MH Battery Pack, the E-DC-6 connection to the external DC power source will allow operation of the FT-818 while charging of the SBR-32MH is in progress."

    Nothing I see in the manual about leaving the Ni-MH installed all the time. I saw some forum content somewhere about not leaving the battery connected.
  5. N4FZ

    N4FZ XML Subscriber QRZ Page

    Once it has charged, you are fine, it will automatically turn off charging after the TIME you set for charge. My FT-818ND battery will lose charge in a few weeks if you don't use it.
    KU3X likes this.
  6. W4WVW

    W4WVW Ham Member QRZ Page

    This FD has convinced me how useless the supplied NiMH battery really is as I completely discharged it in about 90 minutes with minimum transmit time. It's coming out of the radio and the next time I need battery power I'll pick up a LiFePO4 battery/charger pair from Bioenna power with Anderson power pole connector that will plug right into my FT818. 12 AH and I should be good to go.
    N4FZ and KU3X like this.
  7. KU3X

    KU3X Ham Member QRZ Page

    No different than the internal battery in the KX3. Only good for keeping the clock running.

    N4FZ and W4WVW like this.
  8. KI4POT

    KI4POT Ham Member QRZ Page

    I used my 817nd in the field (actually the middle of the woods, not a park, not my backyard) using NiMH AAs rated at 2400mAh and got more than 2hrs each day per set. I used a fresh set Saturday for about 2hrs before packing up, but had charge left in the batteries. I did the same again Sunday. I could probably get 3hrs out of each set. That's with the radio set to 5w (more like 3w actual, but more than the 2.5w setting it defaults to).

    If you're only getting 90min, check the various settings known to consume current (front antenna vs rear, backlight, etc).

    I have a Bioenno battery on the way as well, but it's a 4500mAh model. I don't want to carry more than I have to as virtually all of my operation is in the field.

    N4FZ and W4WVW like this.
  9. KI4POT

    KI4POT Ham Member QRZ Page

    I seem to remember that the radio will continue to send a minuscule charge to the internal battery when connected to an external 12v+ source even if the charging timer is turned off. It wasn't much and it probably won't hurt the batteries in the short term if you're using them from time to time, but I wouldn't leave it that way for weeks or months. For a variety of reasons I do not leave the internal batteries connected when on external power or when in storage.

    N4FZ and W4WVW like this.
  10. W4WVW

    W4WVW Ham Member QRZ Page

    From the SOTABEAMS website:

    1. Because of internal leakage current in the FT-817 or FT-818, users should never store the radio, even for a day, with a battery connected (internal or external). Rather, they should charge the battery and then immediately unplug it. Doing anything else will risk permanent damage to the battery.

    2. Keeping any external power cord plugged into the FT-818 will accelerate the problem for users of the internal battery. This includes the PowerPole Adapter.

    3. Keeping an external power cord plugged into the FT-817 does not increase the leakage current, but the advise from #1 above is still the same."
    K1BQY likes this.

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