[NTLK] MP 2100 rechargeable battery specs

[Forrest]

Not that he requires my endorsement, but I can vouch for Frank in that his word is gold. In the past 15 years since I have been a part of this wonderful community, I have purchased several items from him and have consulted with him on different occasions.

Having re-celled several MP2x00 batteries I can tell you that the device will not work properly—if at all—without both of the items Melvin describes. I had damaged the poly switch on one project and the resulting battery pack did not work—ditto the thermistor.

Be especially wary of Frank’s warning to not overheat the cells when soldering. This is another sure way to ensure they most likely won’t work properly.

Mahalo,
Forrest

Sent from my T-Mobile iPhone 11

> On Apr 8, 2024, at 5:25 PM, Melvin Chia <meloosa110 at gmail.com> wrote:
> 
> I am not referring to the thermistor or thermocouple, which is a pair of wires jointed at their ends.
> The poly switch, on the other hand, (Frank refers to it as a temperature switch), is a connector that completes the series connection between the two rows of batteries in the package. (The red rectangle in Frank’s schematic on his website).
> 
> To answer your question, the thermistor/thermocouple is connected between terminals A&B and the negative end of the battery. I have mine wired exactly as Frank’s instruction and I have no issues. I trust that he has taken all the precautions to ensure the information he provided is correct.
> 
> Curious if anyone has the electrical schematic of the charging/disharging circuit in the 2X00 MessagePads.
> 
> Melvin
> 
>> On Apr 8, 2024, at 16:57, Michael Sheflin <sheflinm at gmail.com> wrote:
>> 
>> Are you referring to the thermistor?  If so, there should be a thread on
>> this from January.  I ended up buying this -
>> https://www.mouser.com/ProductDetail/Bourns/MF-LS180?qs=aMbtsk9EOIaKOmmSNtsPMw%3D%3D
>> 
>> My rebuild is stuck in limbo because I also can't figure out what is
>> supposed to form the contact - is that the thermistor itself?  It's not
>> 100% clear to me, either from the disassembly or from Frank's tutorial what
>> is supposed to actually be the contact if not the thermistor itself.  I
>> also could have been a bit less sloppy.
>> 
>> 
>>>> On Mon, Apr 8, 2024 at 4:05 PM Melvin Chia <meloosa110 at gmail.com> wrote:
>>> 
>>> Oops, I guess I won’t spot weld them to the batteries next time.
>>> :(
>>> 
>>> Melvin C
>>> 
>>>>> On Apr 8, 2024, at 11:35, Dave Shevett <shevett at pobox.com> wrote:
>>>> 
>>>> My understanding is that temperature switch is very difficult to source
>>> - I
>>>> have a project to put in new cells in my 2100 as well, and I have the
>>>> batteries, but most of the tutorial say "WHATEVER YOU DO, DONT DAMAGE THE
>>>> TEMP SENSOR, YOU CANT GET REPLACEMENTS"
>>>> 
>>>> So curious if that's just rumor :)
>>>> 
>>>>> On Mon, Apr 8, 2024 at 11:21 AM Melvin Chia <meloosa110 at gmail.com>
>>> wrote:
>>> 
>>>>> ………
>>>>> Melvin C
>>>>> ----------------------------------------------------------------------
>>>>> 
>>>>> http://newtontalk.net
>>>>> http://twitter.com/newtontalk
>>>> 
>>>> 
>>>> 
>>>> --
>>>> Dave Shevett
>>>> shevett at pobox.com
>>>> ----------------------------------------------------------------------
>>>> 
>>>> http://newtontalk.net
>>>> http://twitter.com/newtontalk
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>>> 
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