D8 Battery Life (using the internal battery tray w/ 4 AA's)

From: Gary Davis <gdavis@loop.com>
Subject: D8 Battery Life (cont.)
Date: Tue, 20 Aug 1996 12:56:06 +0000

I tested the D8 continuous running time last night and got 6:59 (ie,
just under 7 hours) with a set of Eveready Energizers.  I have gotten
similar times with Radio Shack alkalines and Duracell alkalines.

I will go on record as saying, "You will get more than 6 hours of
continuous recording (without using the mike input, output circuit,
or light) from a D7 or D8 with fresh, name brand Alkaline batteries."

Note that the output circuit adds approximately 20% to the current
draw and you should plan accordingly.

I also measured the current draw of a D7 and found it to be identical
to a D8.  I also found recording in SP and LP to be identical.

---Now for the sceptics, here are some things you should know---

The D8 ran more than 2 hours with only one segment of the battery
life indicator on, so going down to one segment does *not* mean you
are almost out of power.  On the other hand, once it starts flashing,
you really are almost out and have only a few minutes left.

Also, if you put half-used or previously run-to-out batteries in the
D7/D8, you will get three segments at first, but it will drop
quickly.  This is because battery voltage goes up when batteries
aren't in use, but their additional life is limited.  Thus, three
segments lit with fresh batteries might mean 4-5 hours of recording
time, but three segments lit with virtually dead batteries might mean
only 30 minutes of recording time.  So, if you keep track of the
"hours" on your batteries, you can safely use them for 2 or 3
recording sessions, just don't forget to count the playback time too!

(The D7/D8 draws almost identical power in stop, record pause,
record, and playback.  However, the analog output jack draws an
additional 20% when in use; the mike jack, an additional 5%; the
light, about 7%).

Conclusion: if you are trying to use Nicads for recording to save
money, you are probably causing yourself a lot of grief for nothing.
They're ok for playback, but just not worth the trouble for
recording.  Ditto for external "D" packs; get some lithium AA's
instead and get 12-14 hours of recording.  Or just change the
Alkalines every 6 hours.

--Gary


Note from Mike Wagner

I agree with Gary's closing statement, but want to point out that the external "D" packs will also run the D7/8 for up to (or over depending on usage) 15 hours. Using rechargeable alkalines in one of these packs would probably be the cheapest, most environmentally kind solution.


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