Why would someone NOT use rechargeable batteries??

[rockyct]

Originally posted by: thomsbrain

Originally posted by: Mrvile
Because NiMH lose charge if not used for a long time, they're not worth it when used in something like a TV remote, and they usually don't hold as much juice as a good quality alkaline, much less a lithium.

on the contrary. for most modern digital devices, where there is a do-or-die voltage cut-off for operation, the Ni-MH batteries have a far superior life-span per charge, because they provide nearly their full voltage for a long time, then die quickly. alkalines taper off slowly right from the start, meaning you dip below your device's threshold much sooner.

This was addressed above, but basically NiMH batteries die after two months without use. Alkaline's can hold their charge for a least a couple years without use. You probably don't want to use rechargeable batteries in items where you want the battery to last years, rather than months. Stuff like your TV remote, smoke detector, or in your emergency kit.

 

[Calin]

Originally posted by: Mrvile

Originally posted by: Accipiter22

Originally posted by: Mrvile
Because NiMH lose charge if not used for a long time, they're not worth it when used in something like a TV remote, and they usually don't hold as much juice as a good quality alkaline, much less a lithium.

really?? I've been using the ones in my Cannon A20 digicam for 5 years, and they hold as much charge as ever..hmmmmm go rayovac

Well your camera is a high-drain device. Also, when I said they'd lose charge I didn't mean they'd lose maximum charge. I just meant that if you left a set of batteries sitting in, say, a CD player for a year, they would lose a good deal of charge since the last time you used them.

I think they lose half a charge in something like weeks/a few months. Very bad if you have them in "survival grade" things (that you don't use except in an emergency. If you forgot to charge them before the emergency hits, you end up with a half-charged battery).
On the other hand, non-rechargeable keeps most of their charge for years.

Another thing - while battery performance is decreased with temperature, I think non-rechargeable have better characteristics

 

[WhiteKnight]

As a flashlight gadget freak, I use both. However, I don't use rechargeable in my emergency or stored lights because of self discharge. I can just leave a light with alkalines (or better yet lithium primaries) in my car and know that they'll be good for years, rather than days or weeks.

 

[Bateluer]

Originally posted by: SagaLore
The real question is - why don't we have batteries that "self-charge"? You know, a tiny speck of uranium. The atomic decay would charge a coil, which then is stored into an array of capacitors.

Uh . . . I'm not sure I'd want a bunch of radioactive batteries in the house, around young kids and pets.

They'd have to have special disposal procedures as well. And then there would be the inevitable wave of lawsuits against battery makers by people with cancer.

 

[Rock Hydra]

I see NiMh referenced a lot, what about NiCd batteries?

 

[compuwiz1]

the initial investment of such a device can be somewhat dauting. It's kind of like, well, you know what it'd likr.

 

[Vortex22]

I've had the same pair of nonchargeable AA batteries in my Wavebird GC controller for over a year and it's still working.

 

[Rubycon]

NiCd's have lower watt/hr for same give cell volume as nimh. They're also less tolerant of poor charging technique enhancing the "memory" effect.

Low draw, infrequently used loads (smoke alarms, door opener and telly clickers, etc.) are better served by traditional primary cells such as alkalines. The capacity at very low C rates of the Alkaline cell actually exceed nimh due to the rather high self discharge rate if the cells are sitting un-used. High loads like flashlights, photography strobe guns, motorized devices, toys, etc. are all perfect candidates for high capacity nimh cells.

As far as RTG's; these are only feasible where power is needed for extended periods away from all normal power sources. Hence the use in space vehicles. There's other somewhat exotic means to extract power from radionucleide decay that's far safer. The beta battery is one such device. A phosphor lined tube filled with tritium gives off a steady light for 10 or more years. This light excites solar cells generating a weak but steady current. This can be used directly or it can charge capacitors. Higher output betalights will allow these to power surgically implanted devices such as pacemakers. Unlike plutonium powered pacemakers, the device does not have to be recovered from the deceased before cremation, etc.

 

[SagaLore]

Originally posted by: Jeff7

Originally posted by: SagaLore
The real question is - why don't we have batteries that "self-charge"? You know, a tiny speck of uranium. The atomic decay would charge a coil, which then is stored into an array of capacitors.

And that tiny speck of uranium would provide only a tiny speck of power. There's really not all that much energy in radioactive decay... "Each RTG uses the heat generated by the decay of 10.9 kg of plutonium dioxide

See that is the mistake. Don't generate heat, then try and generate power off the temperature differential. Use electromagnetism to produce electrical current off the decay. The particles coming off the atom are rather polarized.

Originally posted by: Bateluer
Uh . . . I'm not sure I'd want a bunch of radioactive batteries in the house, around young kids and pets.

They'd have to have special disposal procedures as well. And then there would be the inevitable wave of lawsuits against battery makers by people with cancer.

Your kids and pets would have more radiation exposure from being in the sun, or from the radon coming up through the ground. In super small quantities its SAFE, plus every battery could have a light lead shielding. What batteries are currently composed of is much more toxic than what I'm proposing.

 

[newmachineoverlord]

Originally posted by: Accipiter22
Just curious, is there any reason what-so-ever that someone wouldn't use rechargeable batteries? They pay for themselves after like 2 or 3 recharges.

The best reasons to use alkalines are: 1. You're on vacation and forgot to bring your charger/batteries.
2. You bought some device that actually included batteries.
3. You have a charger that only charges in multiples of 2, and a device that uses three batteries at a time. (using a set of six batteries can circumvent this issue.) This is my biggest gripe with my otherwise excellent charger.
4. Your charger doesn't charge 9v batteries, and your smoke alarm requires a 9v.

While the self discharge does make them less advantageous in smoke detectors and remotes, I use my oldest NiMH batteries in remotes and wireless wavebird. I find that the performance of ancient 1800mAh batteries is great in these devices. I've only had to switch out batteries on my remote once in the past year using old NiMH. My smoke alarms use 9v batteries, so I'd have to by a 9v recharger and whole now set of batteries for that application. Smoke alarms are low enough drain that the payoff period is years if you consider interest/inflation, unless you bought the batteries for annother purpose and then gave the smoke alarm "hand me downs". If it takes five charges to effectively pay for the charger and battery, well that's probably a 2-5 year period for a smoke alarm.

 

[FoBoT]

i have to be careful, i have kids that don't always pay attention, i don't want them tossing rechargeables

 

[imported_Imp]

Combination of cost and convenience. Sometimes I just get too lazy or forget to recharge my batteries, not like it takes long though. As for cost, it doesn't really matter what you save in the long term since most people don't think that far ahead (or even want to, I don't). It's in the now, and when I got my 2 AAA Panasonic Rechargables, I paid $15. Walking out of the store I saw a pack of 8 Duracells for $4: very very discouraging.

 

[Thraxen]

You guys act like rechargeable alkaline batteries don't exist. I have a bunch and they are what I use in remotes and other low drain devices. The best thing about them is I can charge them all up and once and them drop them in a drawer for later use months, or even years, down the road.

 

[saymyname]

Buying 100 batteries at Costco and never having to worry about it...FTW.

I do use rechargeables but when travelling they're not very practical. Especially in a foriegn country where I might not stay put for very long. My camera uses rechargeable batteries in about 100 pictures and I take more than that in a day when I'm travelling.

Mainly they're only good for my wireless mouse and keyboard.

 

[ThaPerculator]

I use rechargables a ton, as I burn through a couple pairs every 1-3 weeks in my bluetooth keyboard and mouse.

 

[jtvang125]

For low drain and non emergency devices (remotes, flashlights...), do rechargeable batteries really last longer than alkalines?

 

[Thraxen]

Originally posted by: jtvang125
For low drain and non emergency devices (remotes, flashlights...), do rechargeable batteries really last longer than alkalines?

Rechargeable alkaline FTW.

 

[pennylane]

I use rechargables for stuff like cameras and that junk.

However, it's nice to have alkalines just in case you need the batteries and it's an emergency or whatever.

 

[Jeff7]

Originally posted by: SagaLore

Originally posted by: Jeff7

Originally posted by: SagaLore
The real question is - why don't we have batteries that "self-charge"? You know, a tiny speck of uranium. The atomic decay would charge a coil, which then is stored into an array of capacitors.

And that tiny speck of uranium would provide only a tiny speck of power. There's really not all that much energy in radioactive decay... "Each RTG uses the heat generated by the decay of 10.9 kg of plutonium dioxide

See that is the mistake. Don't generate heat, then try and generate power off the temperature differential. Use electromagnetism to produce electrical current off the decay. The particles coming off the atom are rather polarized.

Wouldn't NASA/JPL just do that then, instead of using the thermoelectric method they presently rely on to convert the heat of radioactive decay into electricity? If it were actually feasible and efficient to go directly from radiation to electricity, I'd expect them to have done it already, as that would mean far more energy available for space probes, which allows for more powerful instruments, and a higher power transmitter, allowing for greater bandwidth.
That's why I was so dismayed by the discontinuation of the Prometheus Project - they wanted to design and launch fission reactors on Flagship-class missions. This would allow for several kilowatts of power at the very least. My main interest in this would have been a mission to Jupiter's moon Europa. With a fission reactor, there would be power for high-energy radar scanners and who knows what else, to probe deep beneath the surface of Europa, as well as enough power to send a strong signal back to Earth, meaning much more data could be returned than from any previous mission.

Originally posted by: Thraxen
You guys act like rechargeable alkaline batteries don't exist. I have a bunch and they are what I use in remotes and other low drain devices. The best thing about them is I can charge them all up and once and them drop them in a drawer for later use months, or even years, down the road.

Does anyone make them anymore? I haven't seen Renewals for quite some time now.

 

[Dessert Tears]

Originally posted by: jtvang125
For low drain and non emergency devices (remotes, flashlights...), do rechargeable batteries really last longer than alkalines?

Flashlights are low drain and/or non emergency? Frequent use -> rechargeable if possible, infrequent use -> lithium. I guess my Arc AAA keychain light has an alkaline in it.

 

[Zenmervolt]

Originally posted by: mercanucaribe
When 4 AAs cost $12, there is no sense whatsoever in buying alkalines for anything other than remotes and smoke detectors. And I think Nimh has long surpassed alkaline for power capacity.. Of course no one publishes mah ratings for their alkalines.

NiMH batteries don't last worth sh*t in an SLR flash. There's a big difference between 6 volts (4 times 1.5 volts) and 4.8 volts (4 times 1.2 volts) when you're feeding a large flash unit.

ZV

 

[Rubycon]

Originally posted by: Jeff7

Wouldn't NASA/JPL just do that then, instead of using the thermoelectric method they presently rely on to convert the heat of radioactive decay into electricity? If it were actually feasible and efficient to go directly from radiation to electricity, I'd expect them to have done it already, as that would mean far more energy available for space probes, which allows for more powerful instruments, and a higher power transmitter, allowing for greater bandwidth.
That's why I was so dismayed by the discontinuation of the Prometheus Project - they wanted to design and launch fission reactors on Flagship-class missions. This would allow for several kilowatts of power at the very least. My main interest in this would have been a mission to Jupiter's moon Europa. With a fission reactor, there would be power for high-energy radar scanners and who knows what else, to probe deep beneath the surface of Europa, as well as enough power to send a strong signal back to Earth, meaning much more data could be returned than from any previous mission.

The Seebeck effect has greater efficiency at higher deltas. Outer space affords very low skin temps and thus makes this feasible. To get the same splits for terrestrial applications one would have to expend more energy to maintain the split. :Q

Tritiated aerogels and super high efficiency photovoltaic cells promise betaphotovoltaic power systems with direct drive capability in the future. These could be stable and safe enough for consumer applications.

Originally posted by: Zenmervolt
NiMH batteries don't last worth sh*t in an SLR flash. There's a big difference between 6 volts (4 times 1.5 volts) and 4.8 volts (4 times 1.2 volts) when you're feeding a large flash unit.

ZV

Our speedlites get far more flashes and recycle time is MUCH faster with NiMH cells. Alkalines suffer from sloping voltage discharge and higher impedance. That 1.5V/cell advantage fades quickly under high load.

 

[Zenmervolt]

Originally posted by: MS Dawn
High loads like flashlights, photography strobe guns, motorized devices, toys, etc. are all perfect candidates for high capacity nimh cells.

It takes my NiMH cells much longer to cycle my flash than when I use Alkalines. The additional voltage of the primary cells helps a lot.

ZV

 

[Rubycon]

Originally posted by: Zenmervolt
It takes my NiMH cells much longer to cycle my flash than when I use Alkalines. The additional voltage of the primary cells helps a lot.

ZV

What kind of light is it? It doesn't sound like it has a regulated power supply.

 

[Zenmervolt]

Originally posted by: MS Dawn

Originally posted by: Zenmervolt
NiMH batteries don't last worth sh*t in an SLR flash. There's a big difference between 6 volts (4 times 1.5 volts) and 4.8 volts (4 times 1.2 volts) when you're feeding a large flash unit.

ZV

Our speedlites get far more flashes and recycle time is MUCH faster with NiMH cells. Alkalines suffer from sloping voltage discharge and higher impedance. That 1.5V/cell advantage fades quickly under high load.

Interesting. My old Contax TLA30 only lasts about half as long with my 2250 mAh NiMH batteries as it does with lithium "photo" batteries.

ZV