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 ```I have exactly the same experience of all rechargeable types of accus. Very good lesson, Marty! I would like to add a "rescue" operation: If one of the cells won't take charge, try to connect the other cells over it for a few seconds - plus to plus and minus to minus. Usually, 7 batteries - 9,1v - will "kick on" a lost cell. This works with all NiCad types, I don't know how NimHy works. Klas. At 10:53 2003-09-04 -0400, you wrote: >Dear Jeremy: > >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= h >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= t >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= o >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= o >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= y >results: > >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= t >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 > >FIELD USE >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= d >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= e >from that set, indicating that the 1800 vs 1550 may reflect a real capacit= y >advantage. I am always skeptical since the COPPER-TOP scam several years = ago. > >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= s >to one half hour. When you get three consecutive significant drops (why d= o >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. > >BACKUP >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= e >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. >Marty Michener >MIST Software Associates PO Box 269, Hollis, NH 03049 > >EnjoyBirds.com - Software that migrates with you. http://www.EnjoyBird= s.com > >At 06:59 PM 9/3/2003 -0300, you wrote: > >>Thanks for the reply, Walter. Quick and detailed as always. My battery li= fe >>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 say= s >> >"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 the >>apparently charged batteries into the Portadisc it shows a full charge. >>However, this quickly drops. This happens even if I leave it charging all >>night after the green charge light is completely out. >> >> >You should probably verify the condition of your batteries. Maybe try a >> >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 al= l >>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 extremel= y >>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 pa= st >>I have twice had to pay to get my cassette recorder back from the repaire= r >>and then had to send it to the States. A friend of mine sent a microphone >>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. >> >>Jeremy > > ---------- > > >--- >Outgoing mail is certified Virus Free. >Checked by AVG anti-virus system (http://www.grisoft.com). >Version: 6.0.512 / Virus Database: 309 - Release Date: 8/19/2003 > > >[Non-text portions of this message have been removed] > > > >To unsubscribe from this group, send an email to: >m("yahoogroups.com","naturerecordists-unsubscribe"); > > > >Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/= > > > Telinga Microphones, Botarbo, S-748 96 Tobo, Sweden. Phone & fax int + 295 310 01 email: m("bahnhof.se","telinga"); m("telinga.com","info"); ________________________________________________________________________ ________________________________________________________________________ ```