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IC-7300 Clock Battery Failure

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

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  1. ND6M

    ND6M Ham Member QRZ Page

    Am I correct in thinking that every brand new, never used, never connected to power (by the purchaser), 7300 will/may have a damaged battery when it is initially purchased?
    PY3OG likes this.
  2. NZ4J

    NZ4J Ham Member QRZ Page

    I would expect that the batteries, as shipped from the factory, are charged during production testing. My serial number is very, very early. After about 8 months of illness and never applying power to the radio, the battery seems to have lost endurance. This is a sample of one (1).

    Could the battery quality as installed been sub-standard in a batch? I don't know.
    Could the draining of the battery to very low voltage levels damage the lithium cell? It is very well understood that draining LiPo cells can damage the cells. However, this is likely a Magnesium-Lithium cell. But could its performance be degraded by a deep discharge? I don't know.

    I wish I could be more helpful. I am not convinced that there is a systemic problem with the radios.
    Obviously, there are discussions online about clock loss related to time away from the power supply. (

    Statistically, I was not able to find anyone doing an in-depth investigation of the battery behaviors. So, I started down that path.

    Personally, I prefer common, off the shelf, replaceable batteries. But here we are...

    Best regards,

  3. KA9JLM

    KA9JLM Ham Member QRZ Page

    I downloaded the manual, Looking for battery life data. Could not find it.

    That is a very nice radio.

    I would spare the auto tuner, And not use it unless you have a close match.

    I have seen data on some of their radios that use a rechargeable battery, And life expectancy is rated in hours.

    I would use the proper battery and not adapt it, Just so you can buy a battery at Walmart.

    Use the proper replacement. It will not deplete to a unsafe level, It could take many hours to charge. (Just use the radio, Do not ignore it. ;))

    If there is a problem with it going bad, Check the diode that it is connected to.

    Have Fun. :)
  4. ZL2MF

    ZL2MF Ham Member QRZ Page

    I also have the problem with the clock resetting to zero as I do not leave the power connected to the radio when I am not in the shack. Where this suspect battery located in the radio and what is the replacement? Why Icom havent used a normal CMOS type battery is hard to understand?
    Hope soemone can help. I do not have the service manual nor do I know where to get one! I do have the extended manual and schematics but have yet to find the location of this battery.
    Thanks for help in advance!
    73 de maurice ZL2MF
  5. NZ4J

    NZ4J Ham Member QRZ Page


    I will put together some guidance for the battery replacement process including photos of the battery location, part number for the replacement part, and anything else that might be helpful for returning your radio to factory configuration.

    I have parts for installing a much higher capacity battery that should hold up the clock for ridiculously long periods of time while also utilizing a "replaceable" cell type. But the modification will be a significant departure from the factory status. I will not install that modification until the replacement original cell also fails.

    I hate keeping this radio connected to the power mains via the ASTRON power supply. We live in the lightning capital of North America, Florida. THe grounding system that I put in place is substantial and yet no grounding system can prevent losses 100% of the time.
    We routinely disconnect expensive electronics from all power connections, cable system connections, telephone connections, Ethernet connections, and, of course, antenna connections. Living here for quite a few years has taught me that the wires in the house are very capably of transferring induced voltages to electronic systems in the house. With near strikes (<20 feet from structure, palm trees) we have lost TVs, garage door opener electronics and sensors, DVD players, FM tuners, electronic sewing machines, cordless phone bases, VOIP routers, cable modems, and such. It is a fact of living here. It is just a matter of time before you experience a loss.

    I hope to get the information posted in the next few days. And, of course, everyone should be aware that I make no representations regarding the fitness of the modification process and can likely guarantee that the warranty, if still in force, will be void after this modification is applied. Caveat Emptor!

    W1TRY likes this.
  6. KA5IPF

    KA5IPF Ham Member QRZ Page

    If all the battery affects is the clock no big deal to me, I have a watch.
  7. NZ4J

    NZ4J Ham Member QRZ Page

    Hello Maurice:
    The battery has a part number from the schematic: Seiko Instruments ML414HIV01E

    And from the schematic page 8, MAIN UNIT (MAIN2) you can see the clock device, RX-8803LC and the battery in the circuit just to the left of the clock device - BT381 is the ICOM part identifier in the BOM.


    Looking at the images available from here:
    (Main Unit image Fig.7: Bottom interior: ATU, Main Unit. Courtesy IØGEJ)
    The left side of the image is the front of the radio. (The bottom side of the image is the right side of the radio.)
    The battery is located along the front edge of the main unit circuit card.

    The diagram below details a lot of the functionality. The lower/right of the illustration shows the battery location.


    I hope this information helps.


    K2EIR and KA9JLM like this.
  8. NZ4J

    NZ4J Ham Member QRZ Page

    The only problem with a defective battery is that the radio detects that the clock has been lost and pesters the user to set the clock. But the battery must charge to some minimum voltage level before the radio will let you actually set the clock. It is a bit insidious and very frustrating not to be able to use the radio because the clock is not set. It is not a desirable behavior at all!

  9. KA5IPF

    KA5IPF Ham Member QRZ Page

    That would tend to irritate...
  10. VE3GZB

    VE3GZB Ham Member QRZ Page

    I'm a new owner of an IC-7300. Why would an incorrect clock be a problem with the radio in the first place? I'm sure my KWM-2 or SX-28A have no clocks in them and both function just fine.
    KA2OFM and WB1E like this.

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