leaking memory backup cellswas"Re: [Kenwood] TS-850 Display Gone Wild"

[Avi - Modi'im Orchards]

Hi Eric,
Thanks for the link - there appears to be  wealth of information there.
I didn't have time to follow all the links there, but it looks like there 
are two common chemistries used in lithium backup primary cells, and one of 
them is regarded, at least in California, as an environmental hazard - the 
chemical in question is lithium perchlorate (LiClO4). (BTW, the reason 
perchlorate is dangerous is because it inhibits iodide take-up in the 
thyroid). The various links seemed to mostly lead to regulatory issues, but 
I couldn't find information on the nitty gritty of how to neutralize it and 
clean it up.

I did Gaggle "best management perchlorate" and found the following article 
discussing the chemistry of the perchlorate anion,

http://www.dtsc.ca.gov/LawsRegsPolicies/Regs/upload/HWMP_WS_dPerch-Sec2.pdf

but this seems to be going a little deep for our purposes. I mean, I'm just 
a farmer who plays at ham radio and wants to know how to clean up a leaky 
dry cell in his rig!

-avi 4X6UA

----- Original Message ----- 
From: "Eric Lemmon" <wb6fly at verizon.net>

> Avi,
>
> It is surprising that some replies offer a definite solution to the 
> leakage
> problem without knowing what chemistry of coin cell is involved.  There 
> are
> basically two types of lithium coin cells:  "BR" types, which incorporate
> polycarbon/monofluoride chemistry, and "CR" types, which incorporate
> manganese dioxide chemistry.  The cleanup of leaking electrolyte is not 
> the
> same for both types.  The Panasonic lithium cell site may provide the 
> answer
> you seek:
>
> <www.panasonic.com/industrial/battery/oem/chem/lith/coin1.htm>
>
> Although the two types of lithium cells have somewhat differing capacities
> and intended applications, it is not unusual to find the "wrong" type
> installed in a particular radio, simply because it was the type available 
> at
> that time.
>
> 73, Eric Lemmon WB6FLY
>
>
> -----Original Message-----
> From: kenwood-bounces at mailman.qth.net
>
> Subject: leaking memory backup cells was"Re: [Kenwood] TS-850 Display Gone
> Wild"
>
> The two answers I got are a bit different. Clif at Avvid suggests 100%
> denatured alcohol, and Ken KD0AGV suggests baking soda (and BTW warns NOT 
> to
>
> use alcohol - I would gues this is dependant on the kind of alcohol and 
> the
> material from which the substrate of the circuit board is made).
>
> The first answer implies that the pollutants released from a leaking 
> button
> cell are basically organic compounds that need a solvent to be removed, 
> the
> second that they are acidic and need to be neutralized by a base. 
> Sometimes
> the salts that are formed in these acid-base reactions can have their own
> negative effects, too. Are there any chemists on the list who can 
> enlighten
> us as to what the nature is of the stuff leaking from a spent button cell,
> how they would handle the cleanup without endangering the copper traces or
> circuit board substrate or plastic housings of adjacent components, and 
> BTW
> if there are any health hazards involved?
>
> -avi 4X6UA
>
> P.S. - i'm purposely leaving the chain of messages below because I changed
> the subject header.
>
> ----- Original Message ----- 
> From: "Avi - Modi'im Orchards" <tiavi at netvision.net.il>
> To: "Clif Holland" <clif at avvid.com>; <kenwood at mailman.qth.net>
> Sent: Tuesday, December 18, 2007 09:03
> Subject: Re: [Kenwood] TS-850 Display Gone Wild
>
>
>> What technique or material do you recommend for removing and neutralizing
>> the chemicals from battery leaks on PCBs?
>>
>> -avi 4X6UA
>>
>> ----- Original Message ----- 
>> From: "Clif Holland" <clif at avvid.com>
>> To: "Henry" <ka3muf at charter.net>; <kenwood at mailman.qth.net>
>> Sent: Tuesday, December 18, 2007 03:47
>> Subject: Re: [Kenwood] TS-850 Display Gone Wild
>>
>>
>>> You need to get your nose in the radio "RAT NOW", that's immediately for
>>> those furthur north.
>>>
>>> Odds are pretty good the battery is leaking and there are data lines
>>> under it that don't like battery acid. The longer you wait the more
>>> damage.

SNIP>>>

>>> Clif Holland KA5IPF
>>> www.avvid.com
>>>
>>>
>>>
>>>
>>> ----- Original Message ----- 
>>> From: "Henry" <ka3muf at charter.net>

>>>>I know that something about this problem has been posted previously but 
>>>>I
>>>> have been unable to locate it.  The radio still works and I have gotten
>>>> it
>>>> to display the desired freq. on 75 meters but when it was first powered
>>>> up
>>>> today, every item in the display was illuminated and nothing but 8s and
>>>> sometimes vertical lines were displayed in the frequency area.  Is my
>>>> internal battery going south or what?

SNIP