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CMOS Battery replacement on Acernote Light 370

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BT Humble

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Mar 27, 2006, 6:47:01 PM3/27/06
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Hello everyone, I'm hoping for some useful advice:

I've just returned from 2 weeks in Fiji where I was setting up a small
computer lab in a remote school. The hardware consists of eight
Acernote 370 machines (both PC and PCX types), connected to a 200Ah 12V
lead/acid battery, which is charged by a wind turbine and solar panels.
I'll have some photos available in a couple of days, if anyone is
interested.

The problem is that in between my packing these machines for shipment
(9 months ago) and actually seeing them again the CMOS batteries have
gone flat on 4 of them, and so I suspect the remaining 4 will fail
soon. This is a bit of a problem, because I set these machines up to
boot from the CD-ROM then load DOS drivers for a compact flash card in
the PCMCIA slot. They can currently get around this by using a boot
floppy disk, but since I was only able to find a single floppy disk
drive this obviously isn't a long-term solution...

Anyway, to get to the point: Does anyone know the type of CMOS battery
these machines use (I'm assuming it's a coin cell), and where I need to
disassemble the case to get at it? If you have an applicable service
manual that you're willing to e-mail me, I'd be very grateful.
(Needless to say, Adi Maopa Junior Secondary school in Vanua Balavu,
Fiji would be very grateful as well).

Thanks for your help.


BTH

Barry Watzman

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Mar 27, 2006, 10:33:24 PM3/27/06
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Most laptops use NiMH rechargeable batteries for CMOS, not coin-cells
like desktops (by no means is this absolute, quite a few laptops do use
coin cells, but you can't automatically assume either type). I know
that on Toshiba models, with which I'm most familiar, the CMOS batteries
only charge when the computer is actually turned on (no simply connected
to a live AC adapter, but ON), and the specs say full charge from fully
discharged can take 48 hours, and that a full charge should be good for
at least 30 days. Try leaving one on for 12 hours and seeing if the
problem goes away (most of the charging occurs in the first few hours).

budgie

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Mar 28, 2006, 2:11:41 AM3/28/06
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On 27 Mar 2006 15:47:01 -0800, "BT Humble" <bt_h...@bigpond.com> wrote:

>Hello everyone, I'm hoping for some useful advice:

>The problem is that in between my packing these machines for shipment


>(9 months ago) and actually seeing them again the CMOS batteries have
>gone flat on 4 of them, and so I suspect the remaining 4 will fail
>soon. This is a bit of a problem, because I set these machines up to
>boot from the CD-ROM then load DOS drivers for a compact flash card in
>the PCMCIA slot. They can currently get around this by using a boot
>floppy disk, but since I was only able to find a single floppy disk
>drive this obviously isn't a long-term solution...
>
>Anyway, to get to the point: Does anyone know the type of CMOS battery
>these machines use (I'm assuming it's a coin cell), and where I need to
>disassemble the case to get at it? If you have an applicable service
>manual that you're willing to e-mail me, I'd be very grateful.
>(Needless to say, Adi Maopa Junior Secondary school in Vanua Balavu,
>Fiji would be very grateful as well).

I have the .'pdf User Guide and Service Manual, but unfortunately my email would
choke (3.8MB file size).

The battery is listed as "Lithium 3V BR1225-T2V". A quick look throufgh the SG
didn't show a location.

Try Barry's suggestion. I could upload the manuals to my webspace if you can
fetch them from there. Your addie looks unspammed, will upload if you require
and send you the URL.

BT Humble

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Mar 28, 2006, 4:47:13 AM3/28/06
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budgie wrote:
> Try Barry's suggestion. I could upload the manuals to my webspace if you can
> fetch them from there. Your addie looks unspammed, will upload if you require
> and send you the URL.

That would be marvellous, thank you. I thought it would be a coin
battery since the only other laptop I've dissected (an elderly Compaq
LTE Lite/20) used a CR2032 cell. I'll get the school teachers to give
the recharging a try.

My e-mail is bt_h...@bigpond.com

Here are the photos of what I was doing for the last couple of weeks,
in case you're interested:

http://one.fsphost.com/smallsolar/success/mar2006/index.htm


BTH

budgie

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Mar 28, 2006, 6:43:52 AM3/28/06
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On 28 Mar 2006 01:47:13 -0800, "BT Humble" <bt_h...@bigpond.com> wrote:

>budgie wrote:
>> Try Barry's suggestion. I could upload the manuals to my webspace if you can
>> fetch them from there. Your addie looks unspammed, will upload if you require
>> and send you the URL.
>
>That would be marvellous, thank you. I thought it would be a coin
>battery since the only other laptop I've dissected (an elderly Compaq
>LTE Lite/20) used a CR2032 cell. I'll get the school teachers to give
>the recharging a try.

Hope their soldering is up to par, because it is soldered in place.

Email on its way with URL.

Best of luck, and I loved that runway ;-)

The Electric Fan Club

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Mar 28, 2006, 6:55:14 AM3/28/06
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"BT Humble" <bt_h...@bigpond.com> wrote in message
news:1143539233.5...@u72g2000cwu.googlegroups.com...

> budgie wrote:
>> Try Barry's suggestion. I could upload the manuals to my webspace if
>> you can
>> fetch them from there. Your addie looks unspammed, will upload if you
>> require
>> and send you the URL.
>
> That would be marvellous, thank you. I thought it would be a coin
> battery since the only other laptop I've dissected (an elderly Compaq
> LTE Lite/20) used a CR2032 cell. I'll get the school teachers to give
> the recharging a try.
>

Erm. Are you going to try and recharge the BR1225 battery? If so *DON'T*.
It is not a rechargeable battery, and will explode if you try. Someone
posted at the top of this thread that the majority of CMOS batteries are
rechargeable. That has not been true for many years now.

If you cannot find BR1225 batteries then the CR1225 can be used as an
alternative. Most laptops (as someone observed) use CR2032 batteries, but
the BR2032 would be a better choice (but try finding one).


Barry Watzman

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Mar 28, 2006, 11:13:52 AM3/28/06
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That probably is a coin cell, in this specific case.

Hint: For sending files too large to E-Mail, there is a service called
dropload at www.dropload.com. It allows easy transfer of any file(s) up
to 100 megabytes, and it's free (the sender does have to do a one-time
registration). There is a similar service with a 1 gigabyte capacity
limit, but I can't remember the name of it right now.

Barry Watzman

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Mar 28, 2006, 11:17:39 AM3/28/06
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***WARNING*** Be EXTREMELY careful when removing a SOLDERED-IN LITHIUM
BATTERY. This can be really dangerous, because if you get the battery
hot enough (and "hot enough" is well below the melting point of solder),
it can explode. If at all possible, cut out the old battery, then
remove the wires/mounting posts, clean out the holes and install/solder
the new battery.

Barry Watzman

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Mar 28, 2006, 11:23:35 AM3/28/06
to
I posted that a large number of LAPTOPS use NiMH rechargeable batteries
for CMOS, and that is factually correct. (I did not say "all" and I
made it quite clear that coin cells were often used also).

The only thing that was suggested was to leave the computer turned on
for 12 hours. In models that use rechargeable batteries for CMOS, that
will recharge them. In models that use non-rechargeable batteries, of
course, it won't do anything.

In this specific instance, the OP seems to have the worst possible
situation: a non-rechargeable soldered-in lithium battery.

BT Humble

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Mar 28, 2006, 2:54:18 PM3/28/06
to
Barry Watzman wrote:
> I posted that a large number of LAPTOPS use NiMH rechargeable batteries
> for CMOS, and that is factually correct. (I did not say "all" and I
> made it quite clear that coin cells were often used also).
>
> The only thing that was suggested was to leave the computer turned on
> for 12 hours. In models that use rechargeable batteries for CMOS, that
> will recharge them. In models that use non-rechargeable batteries, of
> course, it won't do anything.
>
> In this specific instance, the OP seems to have the worst possible
> situation: a non-rechargeable soldered-in lithium battery.

Easy fellas, we're all friends here... now lets all gather together for
a big group hug! ;-)

I was just thinking about the 12-hour-recharge idea, and they've
already been switched on for that long during the 4 or 5 training
sessions that I ran for the teachers. As for the soldering danger,
I'll mention that they need to use heatsink clips while soldering the
battery in, no biggie.

The workshop is well equipped, I know because I equipped it! ;-)


BTH

budgie

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Mar 28, 2006, 7:50:11 PM3/28/06
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On Tue, 28 Mar 2006 16:13:52 GMT, Barry Watzman <Watzma...@neo.rr.com>
wrote:

>Hint: For sending files too large to E-Mail, there is a service called
>dropload at www.dropload.com. It allows easy transfer of any file(s) up
>to 100 megabytes, and it's free (the sender does have to do a one-time
>registration). There is a similar service with a 1 gigabyte capacity
>limit, but I can't remember the name of it right now.

My PWS has a 20M capacity and is normally empty, so I routinely use it for this
type of delivery, especially as often there are several people wanting the
particular file(s). The choking problem isn't at my sending end, but in the
past I have emailed >5M files to people with yeah_that's_no_problem mailboxes
only to get a rejection message back..

But I'll keep that one in mind.

Barry Watzman

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Mar 28, 2006, 11:13:01 PM3/28/06
to
It was established in a later post that this particular model has the
worst of all possible worlds: a non-rechargeable lithium battery
soldered to the laptop motherboard.

BT Humble

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Mar 29, 2006, 12:06:17 AM3/29/06
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Barry Watzman wrote:
> It was established in a later post that this particular model has the
> worst of all possible worlds: a non-rechargeable lithium battery
> soldered to the laptop motherboard.

Thanks, I realised that, being the Original Poster and all... ;-)


BTH

The Electric Fan Club

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Mar 29, 2006, 1:42:49 AM3/29/06
to

"Barry Watzman" <Watzma...@neo.rr.com> wrote in message
news:44296340...@neo.rr.com...

>I posted that a large number of LAPTOPS use NiMH rechargeable batteries for
>CMOS, and that is factually correct. (I did not say "all" and I made it
>quite clear that coin cells were often used also).
>
> The only thing that was suggested was to leave the computer turned on for
> 12 hours. In models that use rechargeable batteries for CMOS, that will
> recharge them. In models that use non-rechargeable batteries, of course,
> it won't do anything.
>
> In this specific instance, the OP seems to have the worst possible
> situation: a non-rechargeable soldered-in lithium battery.
>

I have not seen a rechargeable CMOS battery in a Laptop manufactured in the
last 3 years. But to be fair, I have not dismantled every laptop
manufactured, just a sample.


budgie

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Mar 29, 2006, 7:29:47 AM3/29/06
to

The 370 series were P1-133 and P1-150. A lot older than three years, and well
inside the rechargeable timeframe.

Barry Watzman

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Mar 29, 2006, 10:00:53 AM3/29/06
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As far as I know, to this day, almost every Toshiba laptop has a NiMH
rechargeable CMOS battery. I actually have not [yet] had to service the
RTC battery in a very recent model, but the RTC batteries in 1400 and
2400 (2002 / 2003) series Toshiba laptops were still rechargeable, and I
beleive that even current production models are still using rechargeable
CMOS batteries.

The Electric Fan Club wrote:

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