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Never buy these batteries
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<blockquote data-quote="Bob Blaylock" data-source="post: 478666" data-attributes="member: 16749"><p>I'm wondering if you are basing your experience with these on a comparable experience with other NiMH batteries, or with disposable Alkaline or carbon-zinc batteries.</p><p></p><p> A very long time ago, at a time when I was using a lot of disposable AA and AAA batteries for various applications, I bought a set of Energizer-brand rechargeable NiMH batteries, and a charger. I found them to be very unsatisfactory. I don't know what the capacity is of the disposable battery types, compared to the claimed 2500 mAH capacity of these NiMH batteries, but it apparently is much greater. No device would run for nearly as long on a set of NiMH batteries as it would on disposables. Further, because NiMH has a nominal voltage of about 1.2 volts per cell, compared to 1.5 volts for alkaline or carbon-zinc, a device meant to run on disposables would, even with a set of fresh, fully-charged NiMH batteries, run as if the batteries were weak.</p><p></p><p> I also found that the NiMH batteries have a fairly high self-discharge rate. Put them into a drawer, just after you have fully charged them, and come back later when you need them, and you'll likely find that they've discharged enough that you can't use them until you charge them again.</p><p></p><p> It didn't take long for me to give up on these batteries, and go back to using disposables. My conclusion is that devices that are made to run on disposable batteries just cannot be expected to perform well on rechargeable—at least not within the parameters of standard types of these batteries. If you could get five NiMH cells to fit in a device made to take four disposables in series (so that you get the same total voltage), and if that device was a relatively low-power device, then you might get acceptable performance.</p><p></p><p></p><p> Anyway, those NiMH batteries sat forgotten in a drawer for well over a decade, until very recently,when I got it into my head to use eight of them to build a new battery pack for my <a href="http://nikonites.com/general-photography/8816-remote-control-stuff-post454932.html#post454932" target="_blank">radio-controlled model tank</a>. In the course of having got it into my head to dig that out and refurbish it, I found that although it was nominally supposed to be 9.6 volts, the battery pack that came with it, when fully charged, only put out about 8 volts; apparently, there's at least one bad cell in it. So, a new pack, built out of these old NiMH cells that had been sitting unused and forgotten for so long, before I even charged it, showed an open-circuit voltage of over ten volts. I was surprised to find that they open circuit voltage was above nominal, even though it had been more than a decade since they were last charged, but not at all surprised that they had no power to deliver.</p><p></p><p> Of course, once I charged them properly, they performed, fine, and in fact, the tank performs better with this new pack than I think it ever did with the old one. Perhaps the old pack was defective from the beginning. Though the tank ran on that pack, I don't think I ever before thought to check the voltage on it, and, as I said, the tank performs better now with the new one.</p><p></p><p>[ATTACH]171690[/ATTACH]</p><p></p><p> The yellow battery pack is the original. The one in red/white/blue is the new one.</p><p></p><p>[ATTACH]171691[/ATTACH]</p><p>[MEDIA=youtube]9aUfm_LNOaw[/MEDIA]</p></blockquote><p></p>
[QUOTE="Bob Blaylock, post: 478666, member: 16749"] I'm wondering if you are basing your experience with these on a comparable experience with other NiMH batteries, or with disposable Alkaline or carbon-zinc batteries. A very long time ago, at a time when I was using a lot of disposable AA and AAA batteries for various applications, I bought a set of Energizer-brand rechargeable NiMH batteries, and a charger. I found them to be very unsatisfactory. I don't know what the capacity is of the disposable battery types, compared to the claimed 2500 mAH capacity of these NiMH batteries, but it apparently is much greater. No device would run for nearly as long on a set of NiMH batteries as it would on disposables. Further, because NiMH has a nominal voltage of about 1.2 volts per cell, compared to 1.5 volts for alkaline or carbon-zinc, a device meant to run on disposables would, even with a set of fresh, fully-charged NiMH batteries, run as if the batteries were weak. I also found that the NiMH batteries have a fairly high self-discharge rate. Put them into a drawer, just after you have fully charged them, and come back later when you need them, and you'll likely find that they've discharged enough that you can't use them until you charge them again. It didn't take long for me to give up on these batteries, and go back to using disposables. My conclusion is that devices that are made to run on disposable batteries just cannot be expected to perform well on rechargeable—at least not within the parameters of standard types of these batteries. If you could get five NiMH cells to fit in a device made to take four disposables in series (so that you get the same total voltage), and if that device was a relatively low-power device, then you might get acceptable performance. Anyway, those NiMH batteries sat forgotten in a drawer for well over a decade, until very recently,when I got it into my head to use eight of them to build a new battery pack for my [URL="http://nikonites.com/general-photography/8816-remote-control-stuff-post454932.html#post454932"]radio-controlled model tank[/URL]. In the course of having got it into my head to dig that out and refurbish it, I found that although it was nominally supposed to be 9.6 volts, the battery pack that came with it, when fully charged, only put out about 8 volts; apparently, there's at least one bad cell in it. So, a new pack, built out of these old NiMH cells that had been sitting unused and forgotten for so long, before I even charged it, showed an open-circuit voltage of over ten volts. I was surprised to find that they open circuit voltage was above nominal, even though it had been more than a decade since they were last charged, but not at all surprised that they had no power to deliver. Of course, once I charged them properly, they performed, fine, and in fact, the tank performs better with this new pack than I think it ever did with the old one. Perhaps the old pack was defective from the beginning. Though the tank ran on that pack, I don't think I ever before thought to check the voltage on it, and, as I said, the tank performs better now with the new one. [ATTACH=CONFIG]171690._xfImport[/ATTACH] The yellow battery pack is the original. The one in red/white/blue is the new one. [ATTACH=CONFIG]171691._xfImport[/ATTACH] [MEDIA=youtube]9aUfm_LNOaw[/MEDIA] [/QUOTE]
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