IC-7300 Clock Battery Failure

Discussion in 'Radio Circuits, Repair & Performance' started by NZ4J, Jun 25, 2018.

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  1. K2EIR

    K2EIR Ham Member QRZ Page

    Good detailed info. Many thanks for the effort, work, and posting. It is Jan 2018 and my clock just developed similar problem. My 7300 is a little more than 2 years old. TNX, Howie
  2. VA3VF

    VA3VF Ham Member QRZ Page

    Thank you very much for this message, and the others with battery location and replacement info.

    I'm 'guilty' of thinking it was no big deal if the battery failed. I wonder if the firmware could be changed to remove the messages and delays when it happens.

    Icom could have designed it in a different way. I would be happy if they had used a socketed battery, making it it user serviceable.
  3. W9GB

    W9GB Ham Member QRZ Page

    Yoshi -

    Panasonic Industrial Coin Cell Battery Catalog
    SCROLL Down to the Coin-Type Rechargable Lithium Batteries

    In Panasonic’s category (3 volt), there are Three (3) Product Lines:
    Vanadium (VL-series), Manganese (ML-series), and Manganese Silicon (MS-series).
    Icom used a Manganese (ML) battery type from Seiko, as noted by Jim, NZ4J.
    Panasonic catalog is useful reference, if you can not find Seiko part (or desire substitute).

    The Panasonic ML621 is 2 mm larger, in diameter (6.8 versus 4.8 for Seiko ML414)
    With its solder tabs, you MAY be able to mount the ML621 Vertically.

    Panasonic ML621 Manganese Rechargable Coin Cell,
    Specifications at 20° C :

    Nominal Capacity: 5 mAh
    Continuous Drain 0.01 mAh
    Diameter: 6.8 mm
    Height: 2.1 mm
    Mass: 0.23 grams
    Last edited: Feb 3, 2019
  4. W4LJ

    W4LJ XML Subscriber QRZ Page

    Just wondered if the folks having dead battery issues kept their radios off (no power supply input) for long periods; more than 2 or 3 weeks. It would seem that, if the power supply to the radio is turned on every couple of weeks for 24 hours, the battery would last indefinitely. However, even if that is done, it does not excuse such a silly design error as this. Why does the radio even HAVE a clock?
    Last edited: Feb 3, 2019
  5. JG7AMD

    JG7AMD Ham Member QRZ Page

    Thank you for information.
    For this troubleshooting, I learned it is not easy to order Li battery now. Digikey won't send Li battery to Japan or overseas.
    It is possible to buy in Japan but such kind of bettey will sell minimum 10 pices. I don't need so much.
    Then my decision was to order ICOM. It was good. I am thinking to upgrade to IC-7610 but the rig uses the same battery.
    ICOM is requesting more QRV activity if the battery keeps good condition.
    Yoshi JG7AMD
  6. G3VDB

    G3VDB Ham Member QRZ Page

    The radio uses the Date and Time in file names, for example, when you record audio to an SD card. This ensures file names are unique and does not require the operator to create a file name.

    Jim G3VDB
    AG5DB and KA9JLM like this.
  7. W4LJ

    W4LJ XML Subscriber QRZ Page

    Good point, but that does not preclude the need for a much improved battery backup design for the clock / date. A wristwatch battery, for example, lasts years, not weeks and can be easily replaced.
    W7UUU likes this.
  8. VA3VF

    VA3VF Ham Member QRZ Page

    If, big IF, Icom indeed 'requested' this, it missed an opportunity to keep its 'mouth' shut.

    Using QRZ typical lingo, I may be an Icom 'fanboy', but the request is asinine. Think better design practices instead.
    Last edited: Feb 20, 2019
  9. WB6BBB

    WB6BBB Ham Member QRZ Page

    I just sent the message below to Ray Novak:

    Given the numerous IC-7300s clock battery failure issues under discussion here:


    it would appear there is a rising chorus of customer discontent.

    It would seem to me, that the responsible thing for Icom to do with regard to the failing clock battery issue, given that they omitted the necessity to power-on the IC-7300 for several days each month to mitigate the battery becoming permanently inoperative, would be to publish an engineered solution to the issue, and implement it at no charge for those radios sold before the addition to manual was made. Anything less opens them to a tarnished reputation if not legal exposure.

    The IC-7300 full User Manual (A7292-4EX-6a © 2016–2018 Icom Inc) is available here: https://www.icom.co.jp/world/suppor...e Station&PDNM=IC-7300&INQWORDSWT=No&INQWORD=

    This notice appears on page 12-11:

    NOTE: The backup battery nor the internal clock

    The IC-7300 has a rechargeable Lithium battery to backup
    the internal clock. If you connect the transceiver to a
    power source, the battery is charged and it keeps the
    correct clock setting. However, if you do not connect the
    transceiver to a power source for a long period of time, the
    battery will discharge. In that case, the transceiver resets
    the internal clock.
    If you do not use the transceiver for a long period, we
    recommend that you connect the transceiver to a power
    source at least once a month. The charging period is two
    days whether the transceiver’s power is ON or OFF.

    Without the current date and time set correctly on the IC-7300, the screen captures will have an incorrect date, and audio recordings will all be placed in the same folder instead of folders with file name of the date they were recorded. So, it is evident that failure of the Seiko ML414H Real Time Clock battery impacts the functionality of the radio.

    The Seiko ML414H data sheet is here:
    https://media.digikey.com/PDF/Data Sheets/Seiko Instruments PDFs/ML414H_E.pdf

    The Seiko ML414H specifications here: https://www.sii.co.jp/en/me/datasheets/ms-rechargeable/ml414h/


    Nominal Voltage(V) 3
    Charge Voltage*1 (V)(Standard Charge Voltage) 2.8 to 3.1
    Nominal Capacity(Voltage Range V)(mAh) 1.0 (3.1V ~2.0V)
    Internal Impedance*2 (Ω) 600
    Standard ChargeDischarge Current(mA) 0.005
    Cycle Life *3 (Time) 50% D.O.D (Depth of Discharge) 300 (10% D.O.D*4)
    Diameter(mm) 4.8
    Height(mm) 1.4
    Weight(g) 0.07

    *1 A constant voltage charge is recommended, but due to a limit in
    charge current, it is necessary to insert a resistor to regulate
    charge current. Please contact us for further details. If a
    constant current charge is required, please contact us for more
    information: https://krs.bz/sii/m/battery_inq_en

    *2 Value measured using AC (Altering Current) method in the fully
    charged state

    *3 Counts of charge and discharge repetition that maintains about
    50% of the minimum guaranteed capacity.

    *4 Depth of Discharge

    The Seiko ML414H battery specifications are on page 18 of the catalog: https://www.sii.co.jp/en/me/files/2018/09/MicroBattery_catalogue_E_2018A_forWeb.pdf
    where it states:

    Large Capacity:
    1.0mAh (typical) (3.1V charge - 2.0V Cut-off)

    Charge Voltage *3 (V) 2.7 to 3.1
    *3: A constant voltage charge is recommended, but due to a limit
    in the charge current, it is necessary to insert a resistor to regulate the charge current.

    Nominal Capacity (Voltage Range V)(3.1 to 2.0) 1.0 (mAh)

    Cycle Life *2 (Time) 300 (10% D.O.D.)
    *2: Counts of charge and discharge repetition that maintains about 50% of the minimum guaranteed capacity

    max. 30 µA/3.1V/72 hours (CC/CV)
    Discharge: 5µA/c.o.v.=2.0V (CC)
    *c.o.v....cut off voltage

    Above in response to:
    On Thu, 21 Feb 2019 20:45:57 -0800, "Donald Rasmussen via Groups.Io" <wb8yqj=yahoo.com@groups.io> wrote:

    >I am glad to see Icom set the record straight in the latest edition of the full manual - be sure to power up the radio at least once a month. Keep it connected for a couple days.
    >I am fine with that, but none of my other rigs have any qualms with extended time in the closet.
    >It seems (anyone set me straight) that the small Seiko rechargeable battery keeps the bigger CR2032 "super capacitor" charged and that's how they work it.
    >Some guys may get a new IC7300 that's been in inventory too long and either the battery went bad from not getting a good initial charge or maybe it was bad from the factory. Rechargeable lithium ion batteries may have a problem if they get too low?
    W4LJ likes this.
  10. KM6XP

    KM6XP Ham Member QRZ Page

    What exactly does “connect to a power source” mean? Does this mean the rig is powered on? Or just connected to my power supply, I assume powered up?

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