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Metalworking (rec.crafts.metalworking) Discuss various aspects of working with metal, such as machining, welding, metal joining, screwing, casting, hardening/tempering, blacksmithing/forging, spinning and hammer work, sheet metal work. |
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#41
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AA battary capacity, Ah (?)
Quit interesting that you said that. Based on some of these posts, I am
going to check the next set of alkalines out of my HP 215. If it has the same problem, then I bet the NiMH's won't be any better. God I hope not, I sure would like a rechargeable solution. Maury. PS, All these conversations have my invention mind going; If I hit the big time and get rich, I may throw you all a bone or something. :-) "jakdedert" wrote in message ... My old Olympus D-320L digicam goes through alkalines like crazy...but when they won't work in the camera anymore, they still have plenty of capacity for flashlights and the like. I'll have to measure the open circuit voltage the next time I change them, IIRC it was something like 1.3 volts. jak "Dave Martindale" wrote in message ... (GregS) writes: On the other hand, there is a GE discount CB walkie-talkie that has been sold in many discount outlets. It uses a fixed amount of cells. It will ONLY work with alkalines. It NEEDS the extra voltage for the thing to output any decent power, 5 watts, where the 1.2 volt cells will cause it to output 1/10th proper power level or 500mw. Which means that it will use half or less of the energy in one set of alkaline cells before you have to replace them with new ones. This certainly fits my definition of "junk". Dave |
#42
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AA battary capacity, Ah (?)
"Eastburn" wrote in message ... Remember - NiCad are 1.25 volts per cell. To low for some electronics to function when in a higher voltage circuit. Bingo... voltage = Alkalines, current = NiMH or Cd. Also - Fry's had 2300mAh AA's when I was there yesterday. $13 for four of them. YIKES! Venger |
#43
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AA battary capacity, Ah (?)
On Tue, 15 Jul 2003 17:33:28 -0500, "jakdedert"
wrote: My old Olympus D-320L digicam goes through alkalines like crazy...but when they won't work in the camera anymore, they still have plenty of capacity for flashlights and the like. I'll have to measure the open circuit voltage the next time I change them, IIRC it was something like 1.3 volts. jak "Dave Martindale" wrote in message ... That's because capacity is dependent on current drain. In the camera under high drain conditions they were done but when you put them in a low drain device they found new capacity. |
#44
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AA battary capacity, Ah (?)
"CMF" writes:
Quit interesting that you said that. Based on some of these posts, I am going to check the next set of alkalines out of my HP 215. If it has the same problem, then I bet the NiMH's won't be any better. God I hope not, I sure would like a rechargeable solution. You need to measure the voltage under load. That's particularly important with high-current devices like a digital camera, or a 5 W radio transmitter. There are some devices where the internal resistance of the alkalines is the problem, not the design of the device. For example, suppose you have a digicam that uses 2 AA cells, and it's been properly designed to operate down to a voltage of 2 V. A pair of alkalines start out a 3 V, but the camera sometimes draws enough current (particularly with the LCD backlight on, and when recharging the flash) that the voltage *under load* drops to 1.3 V. So far so good. Now, after you've taken a few photos, the alkalines have dropped to a no-load voltage of 1.3 V - meaning they still have most of their capacity remaining. But the internal resistance increases as you discharge the cells. Now, when you take a picture, the high current momentarily causes the battery voltage to drop from 1.3 V to below 1 V, and the camera shuts down. NiCd and NiMH cells have *much* lower internal resistance than alkaline cells, and it stays much lower throughout the discharge life of the cells. These cells can deliver several amps of current with very little voltage drop. So, although a pair of cells produce only 2.4 V, you still get something like 2.3 V or 2.2 V under heavy load until the battery is almost completely dead - and the camera continues working. Basically, if alkaline cells power a device for a longer time than current NiMH cells, then either the device has very low current drain (where alkaline still does have more capacity), or the device hasn't been designed to operate all the way down to 1 V per cell (bad design). While if NiMH cells operate the device longer than alkaline cells, it's probably because the device draws lots of current and the alkaline cells have too much internal resistance. Dave |
#45
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AA battary capacity, Ah (?)
Actually, after borrowing a decent electronic multi-tester (would love to
buy one but if I had that kind of money I wouldn't be selling ironing boards) I will rig to the power connections inside the camera and wire it to a makeshift battery pack and test that. I can see how to do it now. I will probably use some 24 gauge wire from a cat5 cable unless you think that will not be enough. As for measuring the way I did already, there are four batteries, two each that drop down two slots and connect to the power leads inside the camera. The lid closes the circuit, so I am testing the four batteries and the camera circuitry I guess, with the lid open. I don't know how valid that test is, but I am having fun. Instead of all this testing, I could just get the charger and some batteries, I just don't want to find out it won't work because this camera, apparently an older model of the HP215, needs the alkaline voltage rush, so to speak. "Dave Martindale" wrote in message ... "CMF" writes: Okay, let me ask, how do I test under load? Does this mean see what happens to the voltage while in the camera, or when snapping a picture? Ideally, yes. If you can't do that because you can't reach the camera's battery terminals with the battery installed, maybe you can use clip leads to connect the batteries (in a battery holder) to the camera terminals. And if you can't do that either, perhaps you can measure the current drawn by the camera, and then use a resistor that draws about the same amount of current. What's practical depends on the mechanical layout of your camera. I was piddling around with it this morning using an analog Sperry SP-152a multitester, and it was showing 5 volts when I just took the battery cap off and touched the leads, where if I took all four batterys out and laid end to end, it showed 6. Remember, I am virtually ignorant of this stuff, and ha ve a cheap tester. The same tester shows almost 2 volts per battery, so I am limited by a silly tester. What in the camera is taking almost an entire volt even with the camera turned off? If you "take the battery cap off", what does the complete circuit with the multimeter look like? Are you connecting the meter from the same point where the camera takes its power? Or are you really removing an inter-battery connection from the "far" end of the batteries and measuring the voltage between the two exposed battery ends, but with the camera electronics still in the loop? If you're just measuring between two batteries in the middle of the battery string, but the camera is also still in the circuit, the voltage you measure just depends on the relative resistance of your meter and the camera electronics in the "off" state, which is pretty meaningless. If the camera had a mechanical "off" switch, you'd actually measure zero volts in this case. Dave |
#46
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AA battary capacity, Ah (?)
|Instead of all this testing, I could just get the charger and some
|batteries, I just don't want to find out it won't work because this camera, |apparently an older model of the HP215, needs the alkaline voltage rush, so |to speak. As soon as I find my other two NiMh AAs, I'll pop them in my HP215 camera. I have no doubt they will work fine. Will report. |
#47
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AA battary capacity, Ah (?)
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#48
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AA battary capacity, Ah (?)
On Mon, 14 Jul 2003 15:27:05 -0700, "Sofie" wrote
something .......and in reply I say!: What about Dick Smith electronics???? wh....Oh, the half cells. I will give them a go. But they are not the "electronics" shop they once were. ------------------------ "Old Nick" wrote in message ... On Sat, 12 Jul 2003 17:34:37 -0700, "Sofie" wrote something ......and in reply I say!: ************************************************** **************************************** Huh! Old age!. You may hate it, but let me tell you, you can't get by for long without it! Nick White --- HEAD:Hertz Music Please remove ns from my header address to reply via email !! ") _/ ) ( ) _//- \__/ |
#49
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AA battary capacity, Ah (?)
Rex,
Thanks. I just checked old messages, and you said you didn't read the warning that my manual has. If you have the manual, can you look at page 42 in the users guide. Mine says: Caution: Do not use rechargeable batteries with your HP Photosmart 215 digital camera. If yours says this and they still work okay, then I will order some lickety split. If your manual doesn't have this, then I wonder if they eliminated this issue and you have an improved camera? "Rex B" wrote in message ... |Instead of all this testing, I could just get the charger and some |batteries, I just don't want to find out it won't work because this camera, |apparently an older model of the HP215, needs the alkaline voltage rush, so |to speak. As soon as I find my other two NiMh AAs, I'll pop them in my HP215 camera. I have no doubt they will work fine. Will report. |
#50
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AA battary capacity, Ah (?)
Maury Actually, I have been using them in a HP315 (later model) for a year. Just got a HP215 from someone here, and I intend to use rechargeables. But your reminder suggests that I might get out BOTH manuals and see if they both have that warnning. Rex On Wed, 16 Jul 2003 22:21:31 GMT, "CMF" wrote: |Rex, | |Thanks. I just checked old messages, and you said you didn't read the |warning that my manual has. If you have the manual, can you look at page 42 |in the users guide. Mine says: Caution: Do not use rechargeable batteries |with your HP Photosmart 215 digital camera. | |If yours says this and they still work okay, then I will order some lickety |split. If your manual doesn't have this, then I wonder if they eliminated |this issue and you have an improved camera? | | | |"Rex B" wrote in message ... | |Instead of all this testing, I could just get the charger and some | |batteries, I just don't want to find out it won't work because this |camera, | |apparently an older model of the HP215, needs the alkaline voltage rush, |so | |to speak. | | As soon as I find my other two NiMh AAs, I'll pop them in my HP215 camera. |I | have no doubt they will work fine. Will report. | | | |
#51
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AA battary capacity, Ah (?)
Gary Coffman wrote:
... Ted Edwards ... wrote: Your friend was correct in recommending NiMH rechargeables, you can get a decent set of 4 and a charger for about $10 if you look for sales. Never need to pay more than about $15. Please don't do that! Those cheap chargers are either constant current or timer terminated. Pay somewhat more and you can charge your batteries whenever you feel like it without worrying about state of charge. Ray-o-vac has a good charger but, personally, I like the Maha line. My 204 isn't as versatile as some of the newer ones but it works well. I paid Cdn$30 for it a couple years ago. For example, see http://www.thomas-distributing.com/batteries.htm Absolutely right! Get the MaHa charger. It will make your batteries live longer because it won't abuse the batteries. Disagree. I purchased an MH-C204F (and 4 MaHa batteries) 2.5 years ago from Thomas and stopped using it 2 years ago after it ruined 2 sets of batteries. It apparently didn't turn off the fast charge rate when the batteries were charged. The batteries overheated and their plastic covers blistered and I got a very slight burn taking them out of the charger. My other charger (3 years old, obscure-brand POWERhaus Rapid Charger PC-81) still works ok. I bought the 204 so I could charge 2 sets of 4 at once. After the first overheating incident on 25 July 2001, with my Maha set of batteries, voltages on that set were reasonable (about 1.36V each, straight off the charger) and the batteries appeared to work ok for a while, but over the next few weeks or months their capacity appeared to drop, and they now read 0 volts and won't take a charge. The next day (26 July 2001) I put a different set of batteries on the charger and checked every 15 minutes whether the red light had gone off and green light come on, which happened after 2.5 hours, and I decided the first incident had been a fluke. But eventually the 204 ruined another set of batteries and I stopped using it. I agree with the advice to get a good charger with automatic shutoff, but disagree that the Maha 204 is "absolutely right". -jiw |
#52
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AA battary capacity, Ah (?)
James Waldby wrote:
I agree with the advice to get a good charger with automatic shutoff, but disagree that the Maha 204 is "absolutely right". Either your batteries or your charger was defective. My 204 has been in use now for almost two years with no problems whatsoever. Yours is the first report I've seen with this problem. Did you contact the dealer about the problem? Ted |
#53
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AA battary capacity, Ah (?)
In rec.crafts.metalworking Ted Edwards wrote:
James Waldby wrote: I agree with the advice to get a good charger with automatic shutoff, but disagree that the Maha 204 is "absolutely right". Either your batteries or your charger was defective. My 204 has been in use now for almost two years with no problems whatsoever. Yours is the first report I've seen with this problem. Did you contact the dealer about the problem? Ted if you google, he isn't the only one with the auto cycle failing and i now believe that is why this RShack model has a "backup timer". the first set i charged did not shut off at the 1hr mark, keep going until i monitered that the voltage was remaining constant for about 5mins and i unplugged, they were warm, not hot. this was after 90min. but there would have been a 50% overcharge on that first go around, and w/o the timer, who knows? they must not be able to designed a really cheap auto charge sensor just yet. i have decided, based on my experience and that of James, to return the RShack unit and just use the trickle charger that came with the EverReady package at Sam's (19.99 for 8-1850mah w/charger). thanks again to EVERYONE who has posted to this thread, it really makes Usenet SHINE! Best Regards, --Loren |
#54
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AA battary capacity, Ah (?)
Loren,
What kind of batteries is with the eveready? I assume NiMH? Thanks. "lcoe" wrote in message news:UqERa.75567$OZ2.13367@rwcrnsc54... In rec.crafts.metalworking Ted Edwards wrote: James Waldby wrote: I agree with the advice to get a good charger with automatic shutoff, but disagree that the Maha 204 is "absolutely right". Either your batteries or your charger was defective. My 204 has been in use now for almost two years with no problems whatsoever. Yours is the first report I've seen with this problem. Did you contact the dealer about the problem? Ted if you google, he isn't the only one with the auto cycle failing and i now believe that is why this RShack model has a "backup timer". the first set i charged did not shut off at the 1hr mark, keep going until i monitered that the voltage was remaining constant for about 5mins and i unplugged, they were warm, not hot. this was after 90min. but there would have been a 50% overcharge on that first go around, and w/o the timer, who knows? they must not be able to designed a really cheap auto charge sensor just yet. i have decided, based on my experience and that of James, to return the RShack unit and just use the trickle charger that came with the EverReady package at Sam's (19.99 for 8-1850mah w/charger). thanks again to EVERYONE who has posted to this thread, it really makes Usenet SHINE! Best Regards, --Loren |
#55
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AA battary capacity, Ah (?)
lcoe wrote:
In dfw.forsale CMF wrote: Loren, What kind of batteries is with the eveready? I assume NiMH? yes, eight, 1850mah and 1x4charger that does ni-cad also. this one does not do AAA like most of the auto models. thanks to Jazzman for the Sam's plug. --Loren You're gonna kill me for this, but I just looked at my Eveready NiMH batteries that came with that charger and they're only 1,700 mAh. I just misread it when I bought them last year. Oddly enough, they seem to outlast alkalines in my digital camera by about 50% or more. Nevertheless, they are 150mAh less than what I remembered them to me. JazzMan -- *************************************** Please reply to jsavage"at"airmail.net. Curse those darned bulk e-mailers! *************************************** |
#56
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AA battary capacity, Ah (?)
In sci.electronics.repair JazzMan wrote:
lcoe wrote: In dfw.forsale CMF wrote: Loren, What kind of batteries is with the eveready? I assume NiMH? yes, eight, 1850mah and 1x4charger that does ni-cad also. this one does not do AAA like most of the auto models. thanks to Jazzman for the Sam's plug. --Loren You're gonna kill me for this, but I just looked at my Eveready NiMH batteries that came with that charger and they're only 1,700 mAh. I just misread it when I bought them last year. Oddly no worries, i read that off the batteries, NH15-AA 1.2v-1850mah. i cannot find the package so dunno what it says, they must just be keeping the product current. it is amazing, right now, you can pay plenty for the little buggers if you do not keep up with the market. --Loren enough, they seem to outlast alkalines in my digital camera by about 50% or more. Nevertheless, they are 150mAh less than what I remembered them to me. JazzMan -- *************************************** Please reply to jsavage"at"airmail.net. Curse those darned bulk e-mailers! *************************************** |
#57
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AA battary capacity, Ah (?)
On Thu, 17 Jul 2003 23:59:49 GMT, lcoe wrote:
|In sci.electronics.repair JazzMan wrote: | lcoe wrote: | | In dfw.forsale CMF wrote: | Loren, | | What kind of batteries is with the eveready? I assume NiMH? | | yes, eight, 1850mah and 1x4charger that does ni-cad also. this | one does not do AAA like most of the auto models. | | thanks to Jazzman for the Sam's plug. --Loren | | | You're gonna kill me for this, but I just looked at | my Eveready NiMH batteries that came with that | charger and they're only 1,700 mAh. I just | misread it when I bought them last year. Oddly | |no worries, i read that off the batteries, NH15-AA 1.2v-1850mah. |i cannot find the package so dunno what it says, they must just |be keeping the product current. | |it is amazing, right now, you can pay plenty for the little buggers |if you do not keep up with the market. --Loren OK, so where's the best place to buy NiMh batteries? I checked at the local Big Lots and all they have is a few NiCads. |
#58
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AA battary capacity, Ah (?)
In article , Rex B wrote:
| OK, so where's the best place to buy NiMh batteries? | I checked at the local Big Lots and all they have is a few NiCads. Don't put down NiCd's so quickly -- they have lower resistance than NiMh so your flash may recharge faster, and they can be charged faster (2C is usually safe), and they tolerate abuse better, so they last longer. I don't know what Big Lots has (probably not much), but Home Depot sells 4 pack 800 mA AA NiCd packs for $5. (Near/for the solar powered lawn lights.) You can find up to 1100 mA AA NiCds (not at Home Depot) but you'll pay a lot more. NiCd have their niche, but most people want NiMH. For AA NiMH cells, buy them at www.mcmelectronics.com. Search for 58-7740. If you buy at least ten, the price is $0.84 each. Looks like shipping is $3+the actual postal charge. So if you need a lot of batteries, that's a great deal. (Beware, most of their other prices suck.) (I've bought about 50 of these batteries. They work great.) | Newsgroups: sci.electronics.repair,dfw.forsale,rec.crafts.meta lworking Sorry if people consider this offtopic in these groups. But maybe this post will help shut down this long-lasting thread -- Doug McLaren, Virtue has its own reward, but no box office. --Mae West |
#59
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AA battary capacity, Ah (?)
In rec.crafts.metalworking Spehro Pefhany wrote:
On Fri, 18 Jul 2003 14:19:49 GMT, the renowned (Rex B) wrote: OK, so where's the best place to buy NiMh batteries? I checked at the local Big Lots and all they have is a few NiCads. Last time I needed a few in a hurry I got them off a rack at Home Despot. [....] Except for very noncritical applications (toys?), I'd avoid the generic batteries, they don't always live up to their specifications. BTW, don't use NiMH for things like emergency flashlights, they have a high self-discharge rate. Best regards, Spehro Pefhany i have learned a lot from this thread and now understand some of the tradeoffs. the newer cordless phones are a maze of choices and one major factor is that at some point the current draw demands NiMH and the talk/standby time goes _down_. this pdf gives a good ordering of the Uniden offerings: http://www.uniden.com/press/Best_Pho...your_Table.pdf --Loren -- "it's the network..." "The Journey is the reward" Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com |
#61
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AA battary capacity, Ah (?)
On Fri, 18 Jul 2003 14:49:00 GMT, (Doug McLaren) wrote:
|In article , Rex B wrote: | || OK, so where's the best place to buy NiMh batteries? || I checked at the local Big Lots and all they have is a few NiCads. |NiCd have their niche, but most people want NiMH. For AA NiMH cells, |buy them at www.mcmelectronics.com. Search for 58-7740. If you buy |at least ten, the price is $0.84 each. Looks like shipping is $3+the |actual postal charge. So if you need a lot of batteries, that's a |great deal. (Beware, most of their other prices suck.) |This place has cheap prices if you are in the US and want to buy $50+ |worth (I've not tried them): |http://www.cheapbatteries.com/nimh.htm Thanks folks, both good sources. Any place local? |
#62
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AA battary capacity, Ah (?)
Rex B wrote:
OK, so where's the best place to buy NiMh batteries? One very reputable dealer is http://www.thomas-distributing.com/batteries.htm They have a lot of info on their site as well. Ted |
#63
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AA battary capacity, Ah (?)
I'm sure Tanner Electronics has some, but I don't know what brand or
capacity they are. Also, see what Batteries Plus has. Robert "Rex B" wrote in message ... On Fri, 18 Jul 2003 14:49:00 GMT, (Doug McLaren) wrote: |In article , Rex B wrote: | || OK, so where's the best place to buy NiMh batteries? || I checked at the local Big Lots and all they have is a few NiCads. |NiCd have their niche, but most people want NiMH. For AA NiMH cells, |buy them at www.mcmelectronics.com. Search for 58-7740. If you buy |at least ten, the price is $0.84 each. Looks like shipping is $3+the |actual postal charge. So if you need a lot of batteries, that's a |great deal. (Beware, most of their other prices suck.) |This place has cheap prices if you are in the US and want to buy $50+ |worth (I've not tried them): |http://www.cheapbatteries.com/nimh.htm Thanks folks, both good sources. Any place local? |
#64
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AA battary capacity, Ah (?)
Oh, I never thought about Batteries Plus. I'm sure they won't be the
cheapest, but the on on Central just north of 15th street (west side) has some good people working there. I have been for some other things. I was just at Target, and looked at their Eveready chargers for grins. It said the NiMH were 1.2 volt. based on my feeble testing, if my HP215 needs voltage and not amperage for the pictures, they won't work, because I still have 1.3 or so using my analog multitester (I got better with it since whining yesterday) on these, and around 5.5 when I put 4 together after the camera says batteries too low to take a picture. I can still look at pictures stored on the camera for a while even when I cannot take the pictures, so I need to find out whether it is voltage or amperage that I need for pictures. I believe it has already been covered in this thread, I will go back and look unless someone has a quick answer. "Robert Akins" wrote in message ... I'm sure Tanner Electronics has some, but I don't know what brand or capacity they are. Also, see what Batteries Plus has. Robert "Rex B" wrote in message ... On Fri, 18 Jul 2003 14:49:00 GMT, (Doug McLaren) wrote: |In article , Rex B wrote: | || OK, so where's the best place to buy NiMh batteries? || I checked at the local Big Lots and all they have is a few NiCads. |NiCd have their niche, but most people want NiMH. For AA NiMH cells, |buy them at www.mcmelectronics.com. Search for 58-7740. If you buy |at least ten, the price is $0.84 each. Looks like shipping is $3+the |actual postal charge. So if you need a lot of batteries, that's a |great deal. (Beware, most of their other prices suck.) |This place has cheap prices if you are in the US and want to buy $50+ |worth (I've not tried them): |http://www.cheapbatteries.com/nimh.htm Thanks folks, both good sources. Any place local? |
#65
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AA battary capacity, Ah (?)
lcoe wrote:
Don't put down NiCd's so quickly -- they have lower resistance than NiMh so your flash may recharge faster, and they can be charged faster This was true. It still is to a very small extent but there have been major advances in NiMH technology even just in the last couple of years. NiCd have their niche, but most people want NiMH. Given what you say, why would they? I am serious, as I am puzzled. I thought NiMH were far better, but I am beginning to wonder why. 1100mAh is about tops for AA NiCd's whereas NiMH AA's are now up to about twice that. Twice as many pictures on your digital camera or twice as many hours on your GPSR is a significant advantage. If you are into caring for the environment, when they do die and go to the landfill, NiMH does not contain any highly toxic Cadmium. for most all applications, my guess is that they are. but have been too expensive for low-end consumer products. they do self discharge much faster than NiCads, bad for cell/cordless phones, both, they take 1/10C overcharge indefinitely w/o damage, good for phones (read this on a website). This is all old/incorrect data. The self discharge rate is a *little* higher than NiCd but not much any more. Prices have come way down. Zellers (in Canada) is selling 1850mAh AA cells for Cdn$16 for a four pack. Get a smart charger and don't worry about running them right down before re-charging. http://www.imaging-resource.com/ACCS/BATTS/BATTS.HTM http://www.thomas-distributing.com/batteries.htm http://www.buchmann.ca/ "new technology". oh, also, iirc new Nicad's have an indefinite shelf life(?). Are you refering to self discharge or just sitting out of use? If the latter, I have seen no evidence of any superiority of NiCd over NiMH in sealed cells. lastly, i just bot a mid-priced Panasonice cordless 2.4gDSS which uses Nicad's. I don't know what a 2.4gDSS is but if it takes AA cells, try a set of NiMH. You may be pleasantly surprised. Ted |
#66
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AA battary capacity, Ah (?)
"Ted Edwards" wrote in message ... lastly, i just bot a mid-priced Panasonice cordless 2.4gDSS which uses Nicad's. I don't know what a 2.4gDSS is but if it takes AA cells, try a set of NiMH. You may be pleasantly surprised. Ted In cases where an appliance is designed to use and charge NiCads, replacing the cells with NiMH is not necessarily a good idea. For starters, to get the extra capacity out of the cells they will either have to be charged at a proportionally higher current, or for a proportionally longer time. If the base unit has an 'intelligent' NiCad charger it may not charge the cells correctly at all. Dave |
#67
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AA battary capacity, Ah (?)
In rec.crafts.metalworking Ted Edwards wrote:
lcoe wrote: Don't put down NiCd's so quickly -- they have lower resistance than NiMh so your flash may recharge faster, and they can be charged faster This was true. It still is to a very small extent but there have been major advances in NiMH technology even just in the last couple of years. for most all applications, my guess is that they are. but have been too expensive for low-end consumer products. they do self discharge much faster than NiCads, bad for cell/cordless phones, both, they take 1/10C overcharge indefinitely w/o damage, good for phones (read this on a website). This is all old/incorrect data. The self discharge rate is a *little* higher than NiCd but not much any more. Prices have come way down. all? what all? the overcharge immunity? the fact that some manufacturer will design in NiCads even if the cost is similar, to provide product distinction? "new technology". oh, also, iirc new Nicad's have an indefinite shelf life(?). Are you refering to self discharge or just sitting out of use? If the latter, I have seen no evidence of any superiority of NiCd over NiMH in sealed cells. shelf life. this was "common knowledge" some years ago, but never have read anything very authoritive about it. are you saying a NiMH battery, unused, will be as good a a NiCad after 5yrs on the shelf? what exactly _are_ you saying? that you haven't run a test personally so do not believe it? --Loren |
#68
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AA battary capacity, Ah (?)
On Sun, 20 Jul 2003 17:10:25 -0500, the renowned "jakdedert"
wrote: The issue of NiMH's in the cradle too long is easily surmounted...and will get cheaper to do as the demand increases...as always with electronics and production volume. In my (not cheap) Siemens phone system, only a few years old, designed for NiCds, the NiMH batteries last MUCH longer than good quality (Panasonic) NiCds. I don't recommend it, of course, but it WORKS, and it's a lot cheaper than either buying a new phone system or buying dozens of NiCds. Best regards, Spehro Pefhany -- "it's the network..." "The Journey is the reward" Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com |
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AA battary capacity, Ah (?)
Okay, back to a topic that has been covered already, and I can always look
it up, but why look up when you can ask? I have done some testing with my HP215, and the batteries seem to still have 1.2-1.3 volts when they can no longer take a picture, but I can then put them in my headlight flashlight (makes me look like a nerd, but works wonders in attics) and they are just marvelous. I don't know just how long they will go, but they still test right at the good and then '?' on my Sperry analog multimeter. What does the Multimeter check when it does a battery check? Voltage or amperage? The manual is hopelessly inadequate, and about all I am real strong with is the buzz feature. Does this pretty much indicate that 1.2 V NiMH's will not really suit me in this camera? I can't really spend the money for a decent charger and batteries if it really isn't going to work, because that d&%m camera is our main battery pig. Many of the battery powered toys are magically disappearing. I don't suppose someone in Wylie/East Plano would loan me a set of NiMH's for a few days? Thanks, Maury |
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AA battary capacity, Ah (?)
Ted Edwards wrote:
James Waldby wrote: I agree with the advice to get a good charger with automatic shutoff, but disagree that the Maha 204 is "absolutely right". Either your batteries or your charger was defective. My 204 has been in use now for almost two years with no problems whatsoever. Yours is the first report I've seen with this problem. Did you contact the dealer about the problem? I agree that either the batteries or charger were defective. Since the batteries were in use and working well until the charger cooked them, I think the problem is in the Maha 204. No, I didn't contact Thomas Distrib. re the problem. -jiw |
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AA battary capacity, Ah (?)
lcoe wrote:
charge NiMH, maybe a sample defecit. bu, my testing comports with a web page that states, "NiMH" does _not_ exhibit the 'reverse' voltage rise property of NiCAD's when reaching full charge. They do but not as strongly. NiMH smart chargers will do NiCd but the converse is usually false. Ted |
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AA battary capacity, Ah (?)
"lcoe" wrote in message et... In sci.electronics.repair Spehro Pefhany wrote: On Sun, 20 Jul 2003 17:10:25 -0500, the renowned "jakdedert" wrote: The issue of NiMH's in the cradle too long is easily surmounted...and will get cheaper to do as the demand increases...as always with electronics and production volume. In my (not cheap) Siemens phone system, only a few years old, designed for NiCds, the NiMH batteries last MUCH longer than good quality (Panasonic) NiCds. I don't recommend it, of course, but it WORKS, and it's a lot cheaper than either buying a new phone system or buying dozens of NiCds. what does, "easily surmounted" mean, wrt this discussion? --Loren ...meaning that it's fairly easy to design a circuit to stop charging once the battery is fully charged--the advantage cited for NiCads was that they better tolerated overcharging. Look for a smart NiMH charger on a single chip at your electronics supplier soon (today, maybe?)--just add transformer. Once production ramps up, and the circuit--or ones like it--gets second-sourced, the price will go down precipitously...like your $40 VCR which would have cost you $1500 in 1977. jak Best regards, Spehro Pefhany -- "it's the network..." "The Journey is the reward" Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com |
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AA battary capacity, Ah (?)
On Sun, 20 Jul 2003 21:25:30 -0400, Gary Coffman
wrote something .......and in reply I say!: That defintely seems to be the message. So I use my crappy Unidens, which can't really handle NiCd/NiMH, run NiMH, with one extra cell. On Sat, 19 Jul 2003 22:51:19 GMT, (Old Nick) wrote: On Fri, 18 Jul 2003 14:49:00 GMT, (Doug McLaren) wrote something NiCd have their niche, but most people want NiMH. Given what you say, why would they? I am serious, as I am puzzled. I thought NiMH were far better, but I am beginning to wonder why. The big advantage is energy storage per unit weight. For portable things, that means either longer time between recharges, or lighter equipment. Gary ************************************************** **************************************** Huh! Old age!. You may hate it, but let me tell you, you can't get by for long without it! Nick White --- HEAD:Hertz Music Please remove ns from my header address to reply via email !! ") _/ ) ( ) _//- \__/ |
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AA battary capacity, Ah (?)
On Sun, 20 Jul 2003 19:39:27 GMT, Ted Edwards wrote
something .......and in reply I say!: Thanks Ted and others. Capacity ruuuuules OK! G Given what you say, why would they? I am serious, as I am puzzled. I thought NiMH were far better, but I am beginning to wonder why. 1100mAh is about tops for AA NiCd's whereas NiMH AA's are now up to about twice that. Twice as many pictures on your digital camera or twice as many hours on your GPSR is a significant advantage. If you are into caring for the environment, when they do die and go to the landfill, NiMH does not contain any highly toxic Cadmium. ************************************************** **************************************** Huh! Old age!. You may hate it, but let me tell you, you can't get by for long without it! Nick White --- HEAD:Hertz Music Please remove ns from my header address to reply via email !! ") _/ ) ( ) _//- \__/ |
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AA battary capacity, Ah (?)
In rec.crafts.metalworking Ted Edwards wrote:
lcoe wrote: charge NiMH, maybe a sample defecit. bu, my testing comports with a web page that states, "NiMH" does _not_ exhibit the 'reverse' voltage rise property of NiCAD's when reaching full charge. They do but not as strongly. NiMH smart chargers will do NiCd but the converse is usually false. Ted that same site states ....termination methods used for NiMH, include temp sensing...,..timer(?),...(other?).... the RShack unit (returned now) had the switch for NiCadNiMH and two values for the "backup" timer, 2hrs for the former, 1.5 hrs for the latter. likely the product is simply a NiCad charger with timers but they do provide two charging currents, 200ma(?)vs 800ma. (and they lie thru their teeth about the additional modes). --Loren |
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AA battary capacity, Ah (?)
lcoe wrote:
that same site states ....termination methods used for NiMH, include temp sensing...,..timer(?),...(other?).... Just which site is this? Why is it anomynous? If you check the manufacturers sites (Eveready, Ray-oVac, ...) The site I gave you previously (on testing beatteries for cameras) and more, you will find that your reference is simply wrong. Do a search with Google or Dogpile and read some of the material. the RShack unit (returned now) had the switch for NiCadNiMH and two values for the "backup" timer, 2hrs for the former, 1.5 hrs for the latter. I've never been overly impressed with Radio Shack's products so I don't find that a very definitive source. Ted |
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AA battary capacity, Ah (?)
In rec.crafts.metalworking Ted Edwards wrote:
lcoe wrote: that same site states ....termination methods used for NiMH, include temp sensing...,..timer(?),...(other?).... Just which site is this? Why is it anomynous? If you check the well, i just spent an hour trying to find that url, struck out, it must have been a link from a Usnet group. similarly i cannot find another url i visited this am that talks about "Zero Delta V" detection which i assume is for NiMH. it doesn't reverse, just stops rising. and that comports with yet _another_ mystery site that said a NiMH can take 1/10C overcharge indefinitely (or it may have been 1/18C), which shortens the life of Nicads. manufacturers sites (Eveready, Ray-oVac, ...) The site I gave you previously (on testing beatteries for cameras) and more, you will find that your reference is simply wrong. Do a search with Google or Dogpile and read some of the material. the Thomas Distributing site has quite a bit on the charger/battery technology and states that three methods are recognized (by MAHA) to recharge batteries, delta V, timer, and temp, that only delta V does not overcharge. then they say, ....good designs will incorporate all three, like the MAHA.... anyhoo, just my own personal experience, take it for what it is. --Loren |
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AA battary capacity, Ah (?)
lcoe wrote:
and that comports with yet _another_ mystery site that said a NiMH can take 1/10C overcharge indefinitely (or it may have been 1/18C), which shortens the life of Nicads. C/10 for continuous charging of NiMH is still controversial. Some say C/20 and some would like to see continuous float as low as C/60. The jury is still out on the long term stuff since the cells haven't been around all that long and there has been considerable advance in the technology over the last few years. Ted |
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AA battary capacity, Ah (?)
Please kind sir, can you explain what you mean by C/10 and C/20, etc? In
terms my simpleton mind can understand? Thanks. Maury "Ted Edwards" wrote in message ... lcoe wrote: and that comports with yet _another_ mystery site that said a NiMH can take 1/10C overcharge indefinitely (or it may have been 1/18C), which shortens the life of Nicads. C/10 for continuous charging of NiMH is still controversial. Some say C/20 and some would like to see continuous float as low as C/60. The jury is still out on the long term stuff since the cells haven't been around all that long and there has been considerable advance in the technology over the last few years. Ted |
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