Fascinating stuff, Marty.
Before your e-mail arrived I left the Portadisc on Record/Pause with no mic=
and the battery pack lasted 4 hours. I now have the Portadisc beside me as=
I type, with a second battery pack and recording with an MKH20 on phantom
power. The battery life meter is fluctuating between 99% and 85% (it has
now settled on 95% - whoops 90%). Disaster - now it's switched off
completely - after 12 minutes! And the voltage of this battery set, which
was 14.3V when I started is still 13.7V. It looks as if I shall be taking
my old cassette recorder to Amazonia!
I've now put the second battery pack back in the Portadisc. It showed 90%,=
fell immediately to 70% and then, when I started to record, switched off.
I'll follow your suggestions to find out if I have a dud cell somewhere.
At 10:53 04/09/03 -0400, you wrote:
>These suggestions are based on my four trips into tropical recording
>conditions with the HHb.
>All the posts I have read thus far keep referring to battery sets as thoug=
>they were composed of units that behave as similarly as they
>look. Actually, I have been analyzing batteries since grad school in 1962=
>and typically have found one or two in any set of eight used in series tha=
>actually limit the overall performance, because the current flows through
>all eight equally, despite the condition of each cell.
>Here is a very simple test I strongly recommend doing:
>Take a Portadisc caddy of 8 batteries fully charged, out of the unit.
>Place a resistor across the snap connector on the end that will draw SOME
>but not a lot of current, for example 470 ohm.
>It will slowly get noticeably warm because 12 x 12 =3D 144, then divide by
>R=3D470 is about 0.3 watt.
>I actually bought from Radio Shack some of those 9v battery snap
>connectors, and soldered a 470 ohm half-watt resistor to the leads. The
>snap works with the end of the HHb battery caddy, so the test is easy to d=
>whenever you want.
>Under this load of about 25 milleamps, now user a voltmeter to CHECK EACH
>BATTERY for its voltage.
>Ideally you should get all of them to lie somewhere between 1.2 and 1.5
>volts. If one is much lower, replace it. I would even swap them around t=
>get each set to be as closely matched as possible. If you have four sets
>now, having three that are really matched would be better than four
>unmatched. Of my original FUJI set that came with the machine, here are m=
>1.36 1.37 1.37 1.36 1.37 1.37 1.37 1.37
>This set is labelled as 1.2 volts for 1550 mah. So with this low drain in
>place, the resistor would last about 60 hours.
>The results of this test are even more interesting when they are drained a=
>the end of a session, because that is when one or more drop below their
>rated 1.2 volts and may potentially become BACK CHARGED by the
>others. This will ruin a battery, and once it happens all bets about
>matching the set are off.
>My Radio Shack 1800 green set is nowhere nearly as good a match, even
>though they have always been treated as a set, charged and discharged at
>the same rates and times:
>1.39 1.39 1.39 1.40 1.43 1.44 1.42 1.44
>Regarding battery life in the field. I use the HHb on record-pause a lot,
>because I am typically after one or two infrequently-calling species of
>birds, so I walk as if I were recording (quitely, stealthily) much or most
>of my field time. This drives birders nuts, because they always want to
>talk about all the birds they see or hear. Viva las Cryptophones.
>My caddy life varies between about 2 and four real recording hours, and I
>have only a rough idea how much of that time I spend
>listening in the Record-pause mode (88%),
>how much time in STOP (10%) and
>how much time playing back what I just recorded (perhaps 2%)
>Unlike Walt, I have seldom made one full disc by that time, due to the hol=
>mode. I too use the display light ON most of the time.
>Despite the radio shack set variance, I get a bit more field recording tim=
>from that set, indicating that the 1800 vs 1550 may reflect a real capacit=
>advantage. I am always skeptical since the COPPER-TOP scam several years =
>The HHb percentage battery life is to me undecipherable in real use - the
>numbers themselves are meaningless except on any one given day, you watch
>the numbers whatever range they are, over, say, a period of fifteen minute=
>to one half hour. When you get three consecutive significant drops (why d=
>they sometimes RISE???) you turn the unit off for two minutes and that
>writes the TOC onto the disc, then you turn it on and watch the battery
>numbers very carefully to get ready to swap them for a new charged set.
>For emergencies in the rain forest, I carry a set of 8 Photo Lithium
>AA L91 (expensive, light weight, not rechargable) in case both caddys are
>discharged and I am still in good or unusual bird sound environment. In
>Panama I had to rely on these, because the Cana field station only had 110
>v AC electricity for three hours every evening, and no charger I have does
>NiMH that quick.
>QUESTIONS FOR THE GROUP, for HHb
>With NiCd batterys there were numerous FAST chargers available, and I had
>several battery sets that showed me (this was the 1960's) that the fast
>charger actually kept the heavy duty batteries in better condition than th=
>slow chargers. Of course using NiCd s was a totally different world.
>Question: What is the fasted way to charge all 8 NiMH AA batteries
>completely, given that you often do not have "all night" to wait till you
>need the recorder again?
>Question: why don't we have a rechargeable Lithium ion setup for
>recording? For all my field computers, small MDs, palm pilots and video
>machines bought in the last five years I typically get a "use it 4 hours,
>recharge it in one hour" situation. Why not HHb if it is really to be for
>professional use? It is the only machine I own where the ration is
>reversed - use it four hours, recharge twelve hours. I know very few
>professions that can work on that ratio of downtime.
>good luck, Jeremy, my best to you.
>MIST Software Associates PO Box 269, Hollis, NH 03049
>EnjoyBirds.com - Software that migrates with
>At 06:59 PM 9/3/2003 -0300, you wrote:
> >Thanks for the reply, Walter. Quick and detailed as always. My battery l=
> >is much lower than yours and I must now do some more careful testing to
> >find where the problem lies.
> > >There is a switch inside the Portadisc behind the battery caddy. It sa=
> > >"Charge OFF - ON". Set it to on and you should be able to charge the
> > >batteries. That switch is in there in case you are using alkalines and
> > >plug it in, so it won't try and charge alkalines and I know mine was
> > >shipped with charge off. This info is in the owner's manual.
> >The switch is on and the Portadisc appears to be charging. When I put th=
> >apparently charged batteries into the Portadisc it shows a full charge.
> >However, this quickly drops. This happens even if I leave it charging al=
> >night after the green charge light is completely out.
> > >You should probably verify the condition of your batteries. Maybe try =
> > >new set. That's way, way too fast a battery usage. At that discharge
> > >rate the batteries should be very hot to the touch. If they are not,
> > >they do not have anywhere near 2200mAh in them. It's far more likely
> > >that you have a problem with the batteries.
> >I have four new sets of batteries from two different manufacturers and a=
> >give less than one hour of recording. I do use phantom power from the
> >Portadisc, by the way.
> >Thank you for finding out that I have an HHb distributor right on my
> >doorstep but as a result of gruesome past experiences I would be extreme=
> >loath to entrust my precious recorder to a local repair shop. In Brazil
> >they never have the skills nor the spares for specialised work. In the p=
> >I have twice had to pay to get my cassette recorder back from the repair=
> >and then had to send it to the States. A friend of mine sent a microphon=
> >to Sennheiser's local people last month and they returned it still
> >unusable. I'll check out SK Audio Professional Products but with
> >considerable scepticism.
> >I need my recorder for a long trip to Amazonia soon and will see how it
> >goes. If the problems continue and are not the fault of the batteries I
> >will almost certainly send the Portadisc for repair in the States.
> >Thanks again for your help.
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