Hi Rob,
My adapter is wired pin-1 to negative, pin-4 to positive as the 702
manual recommends for use with an external battery pack. Wired that
way, it does nothing until the recorder is turned on, at which point
the external battery pack both charges (tops up)the attached Lion
battery and runs the recorder until the external battery reaches about
Message: 8.
Subject: 5V at which point a little roulette wheel spins inside the recorder
deciding the fate of the file in progress.
Replies from SD to my inquires suggest not using NiMH battery packs
but Lion instead. They did not suggest that anything might be wrong
with my recorder, which leaves me to assume it is normal for the
battery switch-over circuitry (at least in 702 recorders) to be far
from fail safe. I have not yet tried the SD users forum - but will soon.
I have been using AA NiMH because that's what I have around, and did
not want to spend money on a new battery/charger system. I liked the
idea of keeping my external battery pack fairly small, providing just
enough extra to get a full night of recording when combined with the
attached Sony NP-F970 battery. I have tried several AA pack schemes
now, and all have proven unreliable.
For now I just need to put together a bigger battery pack - enough
power to fill an 8GB card without needing the internal battery at all.
I like your D-cell pack, so I'll probably give that a try.
John Hartog
--- In Rob Danielson <> wrote:
>
> At 6:19 AM +0000 5/19/08, John Hartog wrote:
> >Hi Rob, you say, "You can also set the "shut-off" voltage lower, like
> >10 volts when you use the external DC input."
> >
> >Though I have not tried using an external pack without an attached
> >battery also installed, at least on the 702 I think that setting you
> >mention only changes the the low voltage indicator and warning alarm,
> >but the switch over voltage (if I remember correctly, ~7 volts )is not
> >changeable.
>
> I believe you are correct, John. The manual says the 744T
> automatically switches to the internal battery at 9 volts. Starting
> with a 14.4 - 18 volt battery pack extends the operation time
> considerably over that of a 12 volt pack. The factory alarm setting
> of 11 volts seems too high for my higher voltage/higher amperage
> battery packs.
>
> >I still have not solved my battery switch-over problem that results in
> >corrupted files.
>
> I've never had this happen-- no matter the powering situation as long
> as I have a charged Lion battery installed. My 744T always closes
> out the files on the HD and also tells me upon re-powering that it
> powered down early and asks if I want to check for lost files on the
> HD.
>
> How is your Hirose external battery connecter wired? Pin 1(-) and
> 4(+) should provide power without charging the removable 7.2 volt
> battery and the configuration of pin 1(-) and pin 3 (+) should
> provide power and charge the removable 7.2 volt battery. I use the
> later wiring on my primary Hirose cables because it encourages me to
> start off both batteries fully-charged. The wiring shouldn't make a
> difference but its the only thing I can think of that is not
> programming related,.. Did you check the SD users forum? Rob D.
>
> >I set the file size limit to around <2GB to allow for
> >easier DVD archiving: this has turned out to save me some important
> >recordings as it is only the last file being written when the failure
> >occurs that gets corrupted.
> >
> >John Hartog
> >
> >
>
>
> --
>
>
>
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