Are Icom IC-7610 owners experiencing RTC battery failures?

Discussion in 'Radio Circuits, Repair & Performance' started by WB6BBB, Mar 15, 2019.

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  1. WB6BBB

    WB6BBB Ham Member QRZ Page

    Icom IC-7300 owners are experiencing real-time clock battery failure
    issues. More information here:

    The IC-7610 Basic manual <> states on page 8-9:

    "NOTE: The backup battery for the internal clock
    The IC-7610 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 of time,
    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."

    I've not been able to find an IC-7610 Service manual on-line, so I am unable to determine if the IC-7610 RTC battery is the same as the one in the IC-7300. But, because the notice above is similar to the one
    that Icom recently added to the IC-7300 manual, I suspect the batteries are similar.

    This subject may have been discussed in the past, but all I could find was this thread:

    Are IC-7610 owners experiencing RTC battery failures?
  2. W4FBI

    W4FBI Premium Subscriber QRZ Page

    I have the IC-7610 Service Manual.

    The RTC battery is identified as:

    Ref Number: BT4221, Icom part number 3020000390, Manufacturer part: ML414HIV01E

    Not sure if this is the same as a IC-7300

    No failure here (yet)
  3. WB6BBB

    WB6BBB Ham Member QRZ Page

    Thank you for your research and the information you have provided. Where did you find a copy of the IC-7610 service manual?

    Given the IC-7300's RTC battery has a very similar Seiko part number, ML414H, it's safe to assume they are the same minute battery. The Seiko ML414H data sheet is here: Sheets/Seiko Instruments PDFs/ML414H_E.pdf .

    Indeed, Adam Farson has confirmed they are the same in this recent post:

    From: "va7oj" <>
    Date: Fri, 15 Mar 2019 09:59:44 -0700

    Further information: The clock and battery/charging circuits in the IC-7610 and IC-7300 appear to be identical (from the respective service manuals).

    My Icom contacts inform me that there have been no reported instances of battery failure in the IC-7610.
    73, Adam VA7OJ/AB4OJ

    This very small battery was probably designed for use in a digital wristwatch or similar micro-electronic system, and was probably selected by Icom engineers for its low cost, rather than for its suitability for service in an intermittently powered portable radio station, or Go-Box that may remain un-powered for extended periods. While Seiko provides little information on the consequences of completely discharging the ML414H, it is well known that lithium polymer batteries are damaged by being completely depleted/discharged for prolonged periods.

    So, I look for reports of IC-7610 RTC battery failures to begin occurring soon, as is beginning with IC-7300's which were introduced a year or two prior to the IC-7610.

    There is considerably more information on this subject here: .
  4. W4FBI

    W4FBI Premium Subscriber QRZ Page

    Here's my story on the IC-7610 Service Manual: A couple of months back, I called Icom. They told me that only the Paper Manual was available (for a whopping $65 plus shipping). I ordered it. It arrived in about 10 days. It was very disappointing! Could not read the board layout component ID's at all, and the schematics were almost impossible to read. I called and complained - they sent me a PDF of the manual - which I can now magnify and read perfectly.

    I'm not sure if the PDF is available ...
  5. AA5CT

    AA5CT Ham Member QRZ Page

    The kind of thing that makes one go "Hmmmmm".
  6. KA9JLM

    KA9JLM Ham Member QRZ Page

    A switch to disconnect the battery when not in use would have been nice.
  7. W4FBI

    W4FBI Premium Subscriber QRZ Page

    Could you explain the "Hmmmmm" ?

    NG0Z likes this.
  8. W4FBI

    W4FBI Premium Subscriber QRZ Page

    The 7610 service manual is available on "CD" (PDF) from HRO. $39

    I don't recommend the Paper version - too difficult to read (and more expensive). Maybe they have improved it from the one I have - it would need fold-outs for the board layouts and schematics.
  9. WB6BBB

    WB6BBB Ham Member QRZ Page

    I chose to go the same route Icom used in the IC-7800 and install the following in place of the little Seiko battery Icom designed into the IC-7300 and IC-7610:
    CR2032 P189-ND

    I've never had to replace the battery in my IC-7800 manufactured in March, 2009.
    K0UO and KA9JLM like this.
  10. WB6BBB

    WB6BBB Ham Member QRZ Page

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