Electric WW Citizen Eco Drive - Rechargeable battery replacement

Discussion in 'Watch Repair' started by jkamboj, Aug 19, 2009.

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  1. jkamboj

    jkamboj Registered User
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    Jun 3, 2009
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    Toronto, Canada
    Dear Learned members

    I changed the rechargeable battery of Citizen Eco Drive SOLAR-TECH 180. It has movement of GN-4-S and other number is 7871.
    After replacing the MT 920 rechargeable battery, I kept the watch for several hours under a table lamp of 60 W incandescent bulb. Even after about 10 hours of under light, its not charging. When I pull the stem and keep it under light for few minutes and then i push the stem it works. However, after just keeping the watch for two minutes in full dark, it goes jumping two seconds stage.
    I looked at Citizen website, first of all there was no 7871 number on their site, but it does have 7861 which says full charge in 3.5 hours in sun light and 12 hours in cloudy day.
    Does any one have experience like that before?
    What do you suggest in this situation?

    Jaswant Kamboj
     
  2. Genway

    Genway Registered User

    Feb 20, 2009
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    watchmaker
    San Jose, California
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    Jaswant,

    I have similar experience before, it turn out the battery I recieved from supply house was their old stock! Ask for exchange or order from another source.
    I do not think it was installation problem, I believe you are professional watchmaker for years?
     
  3. nick farley

    nick farley Registered User

    Jun 29, 2006
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    Watchmaker
    Winnipeg, Manitoba, Canada
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    I have come across this problem quite a few times. If the battery is completely discharged when you receive it, it's not unusual for it to take quite a while for the charge to build up to a point where it will run the watch reliably. If you bought it from a supplier that sells a fair number of these batteries then it shouldn't be old stock. The correct battery for this movement is 295.56. You mention that it's marked MT920, but there are several batteries with the same number, but have different gold contacts spot welded to the negative terminal. Do you have the correct one?
     
  4. doug sinclair

    doug sinclair Registered User
    NAWCC Member

    Aug 27, 2000
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    Calgary, Alberta
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    Nick is quite correct regarding ordering these capacitiors. It is imperative that the Eco-Drive movement caliber number be included with your order. Did you give the supplier that info, and does the new cell compare exactly to the original?
     
  5. le arsi

    le arsi Registered User
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    Jul 7, 2008
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    Watchmaker,tower clockmaker, watch repair teacher/
    Philippines
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    There is a correct method of diagnosing a solar quartz watch to pinpoint the trouble whether its the capacitor or the mechanical block or the electronic block including the solar panel and its circuit. You will need a simple multimeter. If you do not have this or no knowledge of doing the electrical test and you just replace it without checking before buying a new capacitor then you're going to waste not only money but your precious time.
     
  6. jkamboj

    jkamboj Registered User
    Donor

    Jun 3, 2009
    107
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    0
    Toronto, Canada
    Dear all

    Thanks for your looking into my problem. Today, I charged the watch for 4 hours in bright sunlight of Toronto. When I kept the watch for charging, I pulled the stem and later after 4 hours of charging in sunlight, when i started the watch, by pushing the stem in and the watch worked fine. However, when i put the watch for thirty second in dark room, the watch start doing the trick of two seconds sweep. Then another four hours of charge in sunlight. Again the same thing, once the watch goes to dark room for 30 seconds, the watch shifted to two second jumps.
    The watch behaves the same way with the old as well as the new replacement secondary battery. It does not charge enough energy to sustain just for thirty seconds in dark.

    One thing to note here is that after charging it in sunlight for four hours and then shifting the watch to dark room for 30 seconds led to the stopping of watch (second hand movement). Later when the watch transferred to light it started jumping two seconds etc. Which suggests that there was not enough charge for the watch to sustain just for 30 seconds. Is it due to charging problem, circuit problem or mechanical reasons? Any idea?

    As suggested by Mr Arsi, I do have multimeter. Is there an old thread explaining how to do testing on watch as suggested by Mr Arsi?

    I look forward to hear suggestions on this issue.

    Jaswant Kamboj
     
  7. jkamboj

    jkamboj Registered User
    Donor

    Jun 3, 2009
    107
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    Toronto, Canada
    Dear Doug and Nick
    Thanks for the response.
    I purchased the secondary battery from Somal International and yes I did mention the movement number, that specifically, when i asked about the availability of battery, the guy attending the phone asked about the movement number which I did tell him 7871.
    I would do more research tomorrow on gold contact points and let you know the progress.

    Jaswant Kamboj
     
  8. nick farley

    nick farley Registered User

    Jun 29, 2006
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    Watchmaker
    Winnipeg, Manitoba, Canada
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    I get most of my rechargeables from Somal too, and they sell large quantities of them. They won't be old stock, especially as this particular battery is one of the biggest sellers. That suggests one of two possibilities. One is that the charging circuit is defective, which is unlikely. The other is that the gold contact on the battery isn't making contact with the circuit, which isn't unusual. Take the circuit out and check the underside. Citizen/Miyota movements use one of two methods to connect the solar panel to the charging circuit - some use two long gold colored springs that join conductive pads on the solar panel and make direct contact with the circuit, others use gold colored "fingers" that do the same job. The gold contact on the rechargeable battery is short and stubby and presses against a fairly thick contact that presses on the circuit. Make sure that all these connections are secure. The problem that you have described suggests that the battery isn't connected to the circuit at all, and that the second hand is being powered directly by the solar panel. This in turn suggests that the contact between the solar panel and the circuit is good and that the problem lies in the connection between the battery and the circuit.
     
  9. jkamboj

    jkamboj Registered User
    Donor

    Jun 3, 2009
    107
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    Toronto, Canada
    Thanks Nick
    I would let you know the progress

    Jaswant Kamboj
     
  10. jkamboj

    jkamboj Registered User
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    Jun 3, 2009
    107
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    Toronto, Canada
    Dear Nick

    The part number is 295-5600. It varies from 295-56 which you suggested. Second difference is, instead of two holes and two depressions, it have only two holes. The two depressions missing might support the point raised by you and other learned members about inability to connect the connectors from charging system to the secondary battery.

    I would talk to Somals right after this mail. I have changed about 20 capacitors and secondary batteries (all purchased from Somal) in last two years but never had any problem. This is the first time and I am learning a lot out of it.

    Would the two depression (placed opposite to two holes) have a bearing in battery not charging?

    Jaswant Kamboj
     
  11. jkamboj

    jkamboj Registered User
    Donor

    Jun 3, 2009
    107
    0
    0
    Toronto, Canada
    Dear Nick

    The part number is 295-5600. It varies from 295-56 which you suggested. Second difference is, instead of two holes and two depressions, it have only two holes. The two depressions missing might support the point raised by you and other learned members about inability to connect the connectors from charging system to the secondary battery.

    I would talk to Somals right after this mail. I have changed about 20 capacitors and secondary batteries (all purchased from Somal) in last two years but never had any problem. This is the first time and I am learning a lot out of it.

    Would the two depression (placed opposite to two holes) have a bearing in battery not charging?

    Jaswant Kamboj
     

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