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#1
posted to rec.boats.electronics
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Just wondering, Ni-cd charger used on Ni-mh
I know it is not the right place to ask, but maybe some of you know the
answer. I got a bunch of Ni-mh batteries, and a charger that supports normal and Ni-cd charging, so what charging method is the best for these batteries? Puuuf, there goes my brain :-) Wkr Syntax |
#2
posted to rec.boats.electronics
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Just wondering, Ni-cd charger used on Ni-mh
"Syntax" franz(ad)netsolv.dk wrote in news:460a278f$0$7605$157c6196
@dreader2.cybercity.dk: I know it is not the right place to ask, but maybe some of you know the answer. I got a bunch of Ni-mh batteries, and a charger that supports normal and Ni-cd charging, so what charging method is the best for these batteries? Puuuf, there goes my brain :-) Wkr Syntax Set the charger to charge NiCd batteries and it will charge the NiMh just fine...albeit a little slowly as they are probably much larger in AH capacity. I'm currently buying NiMh "AA" cells at 2.5 AH! Larry -- Alltel Axcess TV - 10 minutes of TV then it dumps you until you click to get 10 minutes more. It SUCKS! |
#3
posted to rec.boats.electronics
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Just wondering, Ni-cd charger used on Ni-mh
"Larry" skrev i en meddelelse ... "Syntax" franz(ad)netsolv.dk wrote in news:460a278f$0$7605$157c6196 @dreader2.cybercity.dk: I know it is not the right place to ask, but maybe some of you know the answer. I got a bunch of Ni-mh batteries, and a charger that supports normal and Ni-cd charging, so what charging method is the best for these batteries? Puuuf, there goes my brain :-) Wkr Syntax Set the charger to charge NiCd batteries and it will charge the NiMh just fine...albeit a little slowly as they are probably much larger in AH capacity. I'm currently buying NiMh "AA" cells at 2.5 AH! Larry -- Alltel Axcess TV - 10 minutes of TV then it dumps you until you click to get 10 minutes more. It SUCKS! Okay, now i know it is safe to use. Mine are 2 and 2.5 AH, but they actually take less time to charge on the Ni-MH setting than on the normal setting. But thanx. Wkr Syntax |
#4
posted to rec.boats.electronics
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Just wondering, Ni-cd charger used on Ni-mh
"Syntax" franz(ad)netsolv.dk wrote in news:460f5754$0$7610$157c6196
@dreader2.cybercity.dk: Mine are 2 and 2.5 AH, but they actually take less time to charge on the Ni-MH setting than on the normal setting. Yes. The NiMH setting charges at a higher current. Ni-Cd chargers will charge them, but at the slower rate...which isn't a bad thing at all. Larry -- |
#5
posted to rec.boats.electronics
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Just wondering, Ni-cd charger used on Ni-mh
"Larry" wrote in message
... "Syntax" franz(ad)netsolv.dk wrote in news:460f5754$0$7610$157c6196 @dreader2.cybercity.dk: Mine are 2 and 2.5 AH, but they actually take less time to charge on the Ni-MH setting than on the normal setting. Yes. The NiMH setting charges at a higher current. Ni-Cd chargers will charge them, but at the slower rate...which isn't a bad thing at all. You have to be carefull though. NiCD is usually charged either at C/10 rate of at high current, where a drop in voltage is used to detect the end of the charging cycle. The C/10 charge with NiCD cannot overcharge them. However, NiMH batteries show a much smaller voltage drop when full, which might not be detected by a fast NiCD charger. Also, overcharging NiMH at C/10 will certainly damage them. So be careful! Meindert |
#6
posted to rec.boats.electronics
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Just wondering, Ni-cd charger used on Ni-mh
Meindert Sprang wrote:
snip You have to be carefull though. NiCD is usually charged either at C/10 rate of at high current, where a drop in voltage is used to detect the end of the charging cycle. The C/10 charge with NiCD cannot overcharge them. However, NiMH batteries show a much smaller voltage drop when full, which might not be detected by a fast NiCD charger. Also, overcharging NiMH at C/10 will certainly damage them. So be careful! Meindert So for routine purposes and otherwise healthy NiMH cells, what would you use? As an aside, I finally figured out that C/10 means 1/10th of capacity and that C/20 or C/30 is a much better idea. I have a DuraCell quick charger that is identified as a "Class 2" charger but does not tell me much more than that. Do you know what the charge rate on a Class 2 charger is? Output is 1.6V @ 1800mA. I'm about to throw away the DuraCell and get a Maha I think. Jack -- Jack Erbes in Ellsworth, Maine, USA - jackerbes at adelphia dot net (also receiving email at jacker at midmaine.com) |
#7
posted to rec.boats.electronics
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Just wondering, Ni-cd charger used on Ni-mh
"Jack Erbes" wrote in message
... So for routine purposes and otherwise healthy NiMH cells, what would you use? As an aside, I finally figured out that C/10 means 1/10th of capacity and that C/20 or C/30 is a much better idea. I must corrent myself here. C/10 is fine for NiMH. Faster than C/10 will overcharge them when not stopped. I have a DuraCell quick charger that is identified as a "Class 2" charger but does not tell me much more than that. Do you know what the charge rate on a Class 2 charger is? Output is 1.6V @ 1800mA. No idea but the specs suggest that it pumps 1800mA in the cells. The efficiency of NiMH is 66% so when you have a 2500mAh cell, it needs 2500/0.66 = 3800mAh for a full charge. That equals 3800/1800 = 2.1 hrs with your charger. So to see if your charger works, put the empty cells in, and check after 2.1 hrs if the charger has shut off of does so within the next 15 minutes or so. If it doesn't, disconnect it yourself. Meindert |
#8
posted to rec.boats.electronics
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Just wondering, Ni-cd charger used on Ni-mh
Meindert Sprang wrote:
"Jack Erbes" wrote in message ... So for routine purposes and otherwise healthy NiMH cells, what would you use? As an aside, I finally figured out that C/10 means 1/10th of capacity and that C/20 or C/30 is a much better idea. I must corrent myself here. C/10 is fine for NiMH. Faster than C/10 will overcharge them when not stopped. I have a DuraCell quick charger that is identified as a "Class 2" charger but does not tell me much more than that. Do you know what the charge rate on a Class 2 charger is? Output is 1.6V @ 1800mA. No idea but the specs suggest that it pumps 1800mA in the cells. The efficiency of NiMH is 66% so when you have a 2500mAh cell, it needs 2500/0.66 = 3800mAh for a full charge. That equals 3800/1800 = 2.1 hrs with your charger. So to see if your charger works, put the empty cells in, and check after 2.1 hrs if the charger has shut off of does so within the next 15 minutes or so. If it doesn't, disconnect it yourself. Thanks Meindert, The cells I have a Energizer NiMH 2300mAh AA's. They have been charged a couple of times now. The DuraCell quick charger charged them in about 15-20 minutes (blinking LED stopped blinking) on the first use, it took more like an hour after the second use. The batteries show a stable 1.37V aftet they are charged, removed from the charger, and rested for a day or so. I haven't checked to see what they come off the charger at, I need to do that though. But the thing irritates me a little because I have no idea what it is doing and no control over anything. I think I'll treat myself to a better charger and feel a little better for better just for knowing what is going on there. I don't use a lot of batteries and am more interested in getting a good charge that will provide longer service life on things like my Garmin 76Cx handheld than I am in getting fast charges. I decided to try the NiMH's for awhile simply because I think it is better for world in the long run, I don't think it will save me any money in the long run over the 35 cents or so I pay for the disposable alkalines I have been using. I'm probably wrong about that too though. Jack -- Jack Erbes in Ellsworth, Maine, USA - jackerbes at adelphia dot net (also receiving email at jacker at midmaine.com) |
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