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| 2008/8/29-9/3 [Science/Battery] UID:50997 Activity:nil |
8/29 I have 2 AA rechargeable batteries. One is at 300mAH and the other
one is at 600mAH. They used to be 2400mAH. Is there anything useful
I can use them for?
\_ How do you know this?
\_ http://www.amazon.com/Crosse-Technology-BC-900-AlphaPower-Battery/dp/B00077AA5Q/ref=pd_bbs_sr_1?ie=UTF8&s=electronics&qid=1220035985&sr=8-1
\_ http://www.amazon.com/Crosse-Technology-BC-900-AlphaPower-Battery/dp/B00077AA5Q
I love it. PS thanks for tinyurl this for me! I love motd
tinyurl minions.
\_ shortified
\_ How long have you owned them? |
| 4/3 |
|
| www.amazon.com/Crosse-Technology-BC-900-AlphaPower-Battery/dp/B00077AA5Q/ref=pd_bbs_sr_1?ie=UTF8&s=electronics&qid=1220035985&sr=8-1 See all my reviews Ni-MH batteries have become ubiquitous over the past decade. Their low cost and ever-increasing capacity make them a great alternative to alkaline batteries. A low current is gentle on the battery and maximizes its lifespan, but a full charge takes hours. A high current will recharge the battery much faster, but put more strain on it, causing it to wear out prematurely. It also requires careful monitoring of the battery's electrical characteristics to prevent damage. Most of the chargers you can find on the market today use one or the other of these methods. The fast chargers, especially the cheap ones, excel at one thing: destroying perfectly good batteries, because they lack the monitoring circuitry to control the charge current and detect when the battery is full. The slow chargers are usually better, mainly because it's harder to design a really bad slow charger. The BC-900 is a completely different breed: it lets you pick the charge current for each individual battery, has very sophisticated monitoring circuitry that controls the charging process, and is also capable of "renewing" batteries by running full controlled discharge-recharge cycles. I was a little skeptical that a fairly inexpensive product would be so thorough, but after reading all the 5-star reviews on Amazon I decided to give it a try. I'm glad I did: it's all it's cracked up to be, and more. some of them had been destroyed by my previous charger, and it weeded those out right away; some were in pretty bad shape, but a refresh brought them back to life at almost full capacity. The pleasant surprise was to find out all the freebies that come with the charger: four AA and four AAA batteries to get you started, four C-cell adapters, four D-cell adapters, and a nifty carrying case. The less pleasant surprise: it can take several days to refresh batteries. I suppose this explains why the box didn't contain a cigarette lighter car adapter. Also, different batteries will take a different amount of time to complete a similar charging cycle. The charging slots being individually powered and monitored, it's not a real issue, since you can yank out any cell that's finished charging and insert the next one that needs recharging as soon as the little LCD screen warns you it's done. It's reliable, gentle on the batteries, has useful capabilities not found on other models, and comes with a lot of extras. It's more expensive than your ordinary cheap slow charger, but the increased battery lifespan more than makes up for the price difference. Maha Powerex MH-C9000 WizardOne Charger-Analyzer was announced, its looked even better on paper than the BC-900. Here is my assessment for those two chargers: First, let's get the similarities out of the way. Both the BC-900 and the C9000 are powerful battery analyzers/conditioners which can also be used as your everyday battery chargers. Both chargers accept one to four AA or AAA cells with independent charging currents. Next, the differences: 1 SIZE: First thing you'll notice is that the Maha C9000 is HUGE for a 4-AA-cell charger. It is about twice as large as the BC-900 (see my Customer Image for size comparison). Larger size makes the C9000 less suitable as a travel charger. However, as a home charger this is actually an advantage. Extra spacing between cells allows better cooling, and also makes it easier to remove individual cell. The C9000 can charge from 200 to 2000mA for all four cells. So if you routinely need to charge cells in a hurry, the C9000 is better. It is BIG, it is BRIGHT, and it works really well - as a NIGHT LIGHT! The biggest problem with the C9000's display is that it can only show one status for one cell at any one time. It constantly toggles from one status to another, then from one cell to the next. If you have 4 cells in the charger, it takes 48 seconds or more (depending on the current activity) for the display to cycle through all 4 cells. So if you missed one reading, you have to wait for it to cycle through again. The C9000 has a similar function called 'CYCLE', but it is very tedious to use (see the USER INTERFACE section for details). In addition, the C9000 also has a 'BREAK-IN' mode which supposedly should be applied to new cells before first use, or to really old cells that have not been charged for years. Beware that this operation takes at least 39 hours to complete, so I doubt many people would actually use it. This has caused a lot of frustrations among users, but there is a way to work around it (see my BC-900 Customer Image for details). If the battery terminal voltage is too low, it automatically starts charging at 125mA until the voltage rises above 1V, then it continues with the programmed charging current. The C9000 also measures battery internal resistance when a cell is first inserted. If the user inserts an alkaline cell (which has much higher internal resistance), the C9000 displays 'HIGH' and refuses to charge it. This is a good safety feature, except that it also incorrectly rejected most of my NiMH cells bought four or five years ago. So I cannot use the C9000 to charge or recondition those old cells, even though the BC-900 reports that they still have around 1000mAh of capacity left. The only limitation is that once the charging current is fixed, you cannot subsequently select a larger current without removing all cells. The C9000 has four completely independent charging circuits that can be programmed to different currents. This may sound great at first, but in practice it soon becomes a burden, because you often need to press dozens of key stokes to program all four cells. For example: If you want to recondition four cells on the BC-900, you'll go through the following sequence: - insert in all 4 cells at once - press MODE to select DISCHARGE/REFRESH (2 keystrokes*) - press CURRENT to select charging current (2-3 keystrokes) * Note: need to press and hold MODE for 1 second for the first keystroke On the C9000, you can insert in all 4 cells at once, but you have to program them one at a time. Which means: - press UP/DOWN to select 'CYCLE', then 'ENTER' (2-5 key strokes) - press UP/DOWN to select charging current, ENTER (1-11 key strokes) - press UP/DOWN to select discharging current, ENTER (1-6 key strokes) - press UP/DOWN to select number of cycles, ENTER (1-13 key strokes) Congratulations! BOTTOM LINE: The Maha MH-C9000 is, without a doubt, the most powerful NiMH AA battery analyzer/charger in the consumer market. However, certain design issues (such as a single-status LCD panel and ridiculously long programming sequences) make it difficult to use for multiple cells. For most of my routine charging and maintenance of NiMH cells, I'll continue to use my old La Crosse BC-900. Nevertheless, I don't regret buying the C9000, because it was a lot of fun for me to try out all its functions. Plus I now have a really cool (but expensive) night light. I had some batterys that were really dead and it would not attempt to charge them. I put them in my other charger and they did fine in there. But there were some batteries that really were null, that I would not know about if it had not told me. The other problem is that it is a little difficult to figure out how to use. The default setting is fine and maybe that is all most people will ever need. But the instructions are not really adequate, and the print in them is very small. I would stay away from the cheap chargers for two reasons. Often in four batteries only one is bad and it is nice to be able to identify the trouble maker. The second problem with the cheap chargers is they do not detect very well. They do not know for sure if your battery even needs charged. You do not know that and assume your batteries need recharged. The good batteries then get over charged which shortens the life on them and the bad battery will not take a charge. But you really don't know what the problem is because the cheap chargers do not tell you that there is a problem. This charger says NULL, so you know you have a problem with a battery. If it is able to solve that problem, I still don't know. But it is nice just to know which batteries are th... |
| www.amazon.com/Crosse-Technology-BC-900-AlphaPower-Battery/dp/B00077AA5Q See all my reviews Ni-MH batteries have become ubiquitous over the past decade. Their low cost and ever-increasing capacity make them a great alternative to alkaline batteries. A low current is gentle on the battery and maximizes its lifespan, but a full charge takes hours. A high current will recharge the battery much faster, but put more strain on it, causing it to wear out prematurely. It also requires careful monitoring of the battery's electrical characteristics to prevent damage. Most of the chargers you can find on the market today use one or the other of these methods. The fast chargers, especially the cheap ones, excel at one thing: destroying perfectly good batteries, because they lack the monitoring circuitry to control the charge current and detect when the battery is full. The slow chargers are usually better, mainly because it's harder to design a really bad slow charger. The BC-900 is a completely different breed: it lets you pick the charge current for each individual battery, has very sophisticated monitoring circuitry that controls the charging process, and is also capable of "renewing" batteries by running full controlled discharge-recharge cycles. I was a little skeptical that a fairly inexpensive product would be so thorough, but after reading all the 5-star reviews on Amazon I decided to give it a try. I'm glad I did: it's all it's cracked up to be, and more. some of them had been destroyed by my previous charger, and it weeded those out right away; some were in pretty bad shape, but a refresh brought them back to life at almost full capacity. The pleasant surprise was to find out all the freebies that come with the charger: four AA and four AAA batteries to get you started, four C-cell adapters, four D-cell adapters, and a nifty carrying case. The less pleasant surprise: it can take several days to refresh batteries. I suppose this explains why the box didn't contain a cigarette lighter car adapter. Also, different batteries will take a different amount of time to complete a similar charging cycle. The charging slots being individually powered and monitored, it's not a real issue, since you can yank out any cell that's finished charging and insert the next one that needs recharging as soon as the little LCD screen warns you it's done. It's reliable, gentle on the batteries, has useful capabilities not found on other models, and comes with a lot of extras. It's more expensive than your ordinary cheap slow charger, but the increased battery lifespan more than makes up for the price difference. Maha Powerex MH-C9000 WizardOne Charger-Analyzer was announced, its looked even better on paper than the BC-900. Here is my assessment for those two chargers: First, let's get the similarities out of the way. Both the BC-900 and the C9000 are powerful battery analyzers/conditioners which can also be used as your everyday battery chargers. Both chargers accept one to four AA or AAA cells with independent charging currents. Next, the differences: 1 SIZE: First thing you'll notice is that the Maha C9000 is HUGE for a 4-AA-cell charger. It is about twice as large as the BC-900 (see my Customer Image for size comparison). Larger size makes the C9000 less suitable as a travel charger. However, as a home charger this is actually an advantage. Extra spacing between cells allows better cooling, and also makes it easier to remove individual cell. The C9000 can charge from 200 to 2000mA for all four cells. So if you routinely need to charge cells in a hurry, the C9000 is better. It is BIG, it is BRIGHT, and it works really well - as a NIGHT LIGHT! The biggest problem with the C9000's display is that it can only show one status for one cell at any one time. It constantly toggles from one status to another, then from one cell to the next. If you have 4 cells in the charger, it takes 48 seconds or more (depending on the current activity) for the display to cycle through all 4 cells. So if you missed one reading, you have to wait for it to cycle through again. The C9000 has a similar function called 'CYCLE', but it is very tedious to use (see the USER INTERFACE section for details). In addition, the C9000 also has a 'BREAK-IN' mode which supposedly should be applied to new cells before first use, or to really old cells that have not been charged for years. Beware that this operation takes at least 39 hours to complete, so I doubt many people would actually use it. This has caused a lot of frustrations among users, but there is a way to work around it (see my BC-900 Customer Image for details). If the battery terminal voltage is too low, it automatically starts charging at 125mA until the voltage rises above 1V, then it continues with the programmed charging current. The C9000 also measures battery internal resistance when a cell is first inserted. If the user inserts an alkaline cell (which has much higher internal resistance), the C9000 displays 'HIGH' and refuses to charge it. This is a good safety feature, except that it also incorrectly rejected most of my NiMH cells bought four or five years ago. So I cannot use the C9000 to charge or recondition those old cells, even though the BC-900 reports that they still have around 1000mAh of capacity left. The only limitation is that once the charging current is fixed, you cannot subsequently select a larger current without removing all cells. The C9000 has four completely independent charging circuits that can be programmed to different currents. This may sound great at first, but in practice it soon becomes a burden, because you often need to press dozens of key stokes to program all four cells. For example: If you want to recondition four cells on the BC-900, you'll go through the following sequence: - insert in all 4 cells at once - press MODE to select DISCHARGE/REFRESH (2 keystrokes*) - press CURRENT to select charging current (2-3 keystrokes) * Note: need to press and hold MODE for 1 second for the first keystroke On the C9000, you can insert in all 4 cells at once, but you have to program them one at a time. Which means: - press UP/DOWN to select 'CYCLE', then 'ENTER' (2-5 key strokes) - press UP/DOWN to select charging current, ENTER (1-11 key strokes) - press UP/DOWN to select discharging current, ENTER (1-6 key strokes) - press UP/DOWN to select number of cycles, ENTER (1-13 key strokes) Congratulations! BOTTOM LINE: The Maha MH-C9000 is, without a doubt, the most powerful NiMH AA battery analyzer/charger in the consumer market. However, certain design issues (such as a single-status LCD panel and ridiculously long programming sequences) make it difficult to use for multiple cells. For most of my routine charging and maintenance of NiMH cells, I'll continue to use my old La Crosse BC-900. Nevertheless, I don't regret buying the C9000, because it was a lot of fun for me to try out all its functions. Plus I now have a really cool (but expensive) night light. I had some batterys that were really dead and it would not attempt to charge them. I put them in my other charger and they did fine in there. But there were some batteries that really were null, that I would not know about if it had not told me. The other problem is that it is a little difficult to figure out how to use. The default setting is fine and maybe that is all most people will ever need. But the instructions are not really adequate, and the print in them is very small. I would stay away from the cheap chargers for two reasons. Often in four batteries only one is bad and it is nice to be able to identify the trouble maker. The second problem with the cheap chargers is they do not detect very well. They do not know for sure if your battery even needs charged. You do not know that and assume your batteries need recharged. The good batteries then get over charged which shortens the life on them and the bad battery will not take a charge. But you really don't know what the problem is because the cheap chargers do not tell you that there is a problem. This charger says NULL, so you know you have a problem with a battery. If it is able to solve that problem, I still don't know. But it is nice just to know which batteries are th... |