[QUOTE=Malacandra]
Can’t believe no-one’s mentioned it yet, but NiCads and NiMHs are rated at only 1.2V, not 1.5V.
[/QUOTE]
You’re playing with us (can’t tell - no smiley)? Or you can’t read?
[QUOTE=Malacandra]
Can’t believe no-one’s mentioned it yet, but NiCads and NiMHs are rated at only 1.2V, not 1.5V. That said, they will whack out a far larger current than zinc-carbons - their internal resistance is way lower. If you try to draw a lot of current out of zinc-carbons, you’ll find they’re unable to sustain that nominal 1.5V.
[/QUOTE]
Yes - I think it’s possible for some devices to fry themselves by drawing too much current from rechargeables, because of the lower internal resistance - although I wouldn’t expect a modern bit of electronic kit to do something like that.
Furthermore, discharging zinc-carbon batteries deeply and/or quickly can cause them to split and leak corrosive gunk all over the inside of the battery compartment - this may be part of the reason they are advised against here.
[QUOTE=Malacandra]
Can’t believe no-one’s mentioned it yet, but NiCads and NiMHs are rated at only 1.2V, not 1.5V.
[/QUOTE]
Yeah, amazing isn’t it?
[QUOTE=Malacandra]
NiCads and NiMHs… will whack out a far larger current than zinc-carbons - their internal resistance is way lower.
[/QUOTE]
Yep, that’s true. Another interesting thing most people don’t know is that - even though alkaline batteries have more internal resistance than NiCads and NiMHs batteries (of roughly the same size), they have more energy density. I think I read somewhere that (all else being roughly equal) an alkaline battery has about twice the energy density when compared to NiCads and NiMHs batteries. This means that an alkaline battery can supply more total energy to a load if the current is below a certain threshold value.
And since no one has mentioned it, NiCads and NiMHs cells put out 1.2 VDC (nominal) whereas zinc-carbon and alkalines cell put out around 1.5 VDC.
I thought it was AC and they put a diode in the end and it really give pulsing DC … Right … Right??
- I are so smarter than yous guys… ::: * :smack:
[QUOTE=Crafter_Man]
And since no one has mentioned it, NiCads and NiMHs cells put out 1.2 VDC (nominal) whereas zinc-carbon and alkalines cell put out around 1.5 VDC.
[/QUOTE]
Furthermore, the voltage of alkalines is higher than rechargeables. I don’t have the figures to hand, but I think it’s a difference of something like 0.3 Volts per cell.
[QUOTE=Q.E.D.]
Yeah, amazing isn’t it?
[/QUOTE]
At least I knew that interesting fact without Googling it.
/dry
…And yeah, it was the old SDMB “can’t believe no-one’s mentioned {something that’s been mentioned in every other post in the thread so far}” gag. 
I can’t believe nobody knew there was such a thing as irony.
[QUOTE=Mangetout]
I can’t believe nobody knew there was such a thing as irony.
[/QUOTE]
IrMH? What’s the voltage of irony batteries?
CMC +fnord!
0.3 volts less than the goldy and bronzy ones
[QUOTE=Mangetout]
I can’t believe nobody knew there was such a thing as irony.
[/QUOTE]
I’m sorry, could you repeat that? I couldn’t hear over all the whooshing noise. :smack:
[QUOTE=Malacandra]
At least I knew that interesting fact without Googling it.
[/QUOTE]
Cute. But, did you know all the battery chemistry voltages off the top of your head like I did? No? Didn’t think so.
Incidentally, my car battery seemed to have been dropping a few volts, and I thought I might have to replace it, but the mechanic just cleaned the terminals and put lots of what I guess must be Copaslip on them. Now the battery works fine.
but it’s really greasy.
Grease is good. It helps the electricity flow better. 
[QUOTE=Malacandra]
but it’s really greasy.
[/QUOTE]
Probably made of geese.
I read somewhere (can’t remember where) that alkaline batteries are 1.5 volts and rechargeable batteries are 1.2 volts. My rechargeable batteries claim they are 1000 ma (AAA) and 2500 ma (AA).
- When they say “ma” do they really mean milliamp hours? That seems to make more sense than just milliamps.
- How many ma or milliamp hours are alkaline batteries? I’ve never seen one labeled with that information.
I’ve never seen them labelled with *anything but * milliamp hours. Good NiMH rechargeables are up to something like 2800mAh now, for AAs
[QUOTE=Q.E.D.]
Cute. But, did you know all the battery chemistry voltages off the top of your head like I did? No? Didn’t think so.
[/QUOTE]
You left out Li-ion at 3.6v/cell and Li-po at 3.7v/cell 
[QUOTE=Q.E.D.]
Cute. But, did you know all the battery chemistry voltages off the top of your head like I did? No? Didn’t think so.
[/QUOTE]
And the next time I need to know about the 0.06 volts nominal difference between a zinc-carbon and alkaline, or the 0.05 volts between a NiCd and NiMH, that information will come in real handy. 
Now if you want to get into a dick-measuring contest about useless OTTOMH knowledge, I’m there.