Hi folks,
I'm answering a couple of mails simultaneously to save bandwidth. Those
of you who haven't the slightest idea what we are talking about might want
to have a look at http://www.pda-soft.de/emate_battery_pack.html
before reading on. Note there are a couple of "_" in this link which you
usually can't see if your mail client automatically underlines links.
> the eMate doesn't have the restart problem. So, should i refurbish the
> batt pack using hte instructions i found online?
Would make sense in my opinion.
> How can i tell if the temp sticker thingy is bad?
Just measure the resistance. If it is approximately 0 (e. g. like a piece of
wire) it is probably ok.
> If it is bad, can i replace it (is it THAT
> nessicary?)
This is a philosophical question that has been discussed here recently quite
a lot. Fact is that you can replace it with a piece of wire. As long as
the thermistor (the part under the s_p_o_t) is present, ok and properly
connected, the Newton will charge the pack just fine. "Ok" in this context
means a resistance of approx. 10 kOhm, this depends to a certain degree
on the ambient temperature.
The purpose of the "sticker" (which is in fact a temperature switch) is to
cut the
connection if for whatever reason the pack gets too hot. You'd give up
that safety measure if you leave it out.
Stephanie replied:
> I don't have the 'SPOT' in my emate battery pack, and it seems to work
fine.
The s_p_o_t (silvery piece of tape) is just something that holds the
thermistor
in place, it does not have any electrical purpose.
> The temperature sensor tells the emate if the batteries are getting
> over-heated or not, and (i think) if the batteries over-heat it will stop
> charging them. A good thing, but if it's not working perfectly, the emate
> will still charge the batteries.
If the thermistor (the part under the s_p_o_t) is not present, the eMate
will
hopefully do nothing of that sort. At least unless the developers at Apple
haven't done their homework. If it is not present, the eMate has no
reliable means of finding out when to stop charging.
>The eMate monitors battery voltage. That is how it knows when the
batteries
>are full.
It monitors both voltage and temperature.
> The thermistor is a safety cutoff feature. That is, if the batteries are
on
> their way to meltdown, the eMate will stop the charging current rather
than
> turn itself into a molten blob.
When we discussed this the last time, we more or less agreed that the
thermistor
is the component under the s_p_o_t. This is the component that tells the
eMate
the cell temperature.
What you are probably referring to right now is the yellow part that looks
like
a sticker. This is a temperature switch.
> If the eMate used battery temperature to decide when to charge the
> batteries, it'd be on high-current rapid charge any time it was cold.
It doesn't use the temperature to decide when to charge, it uses it to
decide
when to stop charging.
Frank
Newton hardware and software at http://www.pda-soft.de
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This archive was generated by hypermail 2.1.2 : Sat Mar 02 2002 - 10:02:11 EST