@stinks Galvanic/electrochemical cells of a given chemistry have the same nominal voltage. The size of the cell simply determines the energy contained within. That’s why all alkaline cells are listed at 1.5 V (whereas a 9 V battery contains 6 small cells in series.) A D cell is just like a 1.5 V AA cell except the former contains more energy (energy is power over time, power is the product of voltage and current.)
@stinks The problem I see with these is two-fold they are cheaply made and the D size only uses 1 battery. The ones I have from Amazon hold 3 Batteries. Giving you a lot more capacity. I only use these cause regular batteries leak. With them, I can leave batteries in them indefinitely without worry.
@stinks Well, I’ve used a couple of C cells (and some corrugated cardboard and a slug of fender washers) in an LED flashlight in place of D cells. It works fine, but it does change the balance of the flashlight. So I bet these work, too.
(Now I have an urge to try to replace D cells with 2032 coin cells…)
@JT954 Considering rechargeables are 1.2 volts instead of the 1.5 alkalines give you, reducing the size of the battery will probably further reduce its lifespan and/or effectiveness. Short answer is okay in low-drain devices like LED flashlights; not so much in stuff like boomboxes or fluorescent lanterns.
I have some LED flashlights that take D cells. These would probably work OK for that particular application since LEDs have extremely low draw. It’s still not going to last as long as a real D cell would, but in a pinch it would be Ok. On the other hand, I also have an old boom box that uses C cells, and I expect that while I would be able to turn the thing on it would die REALLY quickly because driving those speakers and the motor on the CD player/cassette deck kills batteries quickly. Maybe if I switched to headphones it might last a reasonable time.
These aren’t completely useless, but they are definitely a niche product.
I don’t use it enough to drain the batteries, but I want it ready to go right away. Everyone knows what happens when you leave alkaline cells in a flashlight (or just about any other electronic). They leak.
With AAs, you could either drain them fast enough to not leak, or use cheapish rechargeables.
Suppose you put lithium AA batteries in these?
I have very carefully recharged energizer lithium AA cells in a Nimh charger
Requires manually monitoring temperature and charge for safety
Okay went and checked the energizer data sheets
Even a lithium AA only has about a third of the capacity of a D alkaline (very approximate estimate 3000mah vs 10000mah over 1 volt, the D will keep going at lower voltage which would be fine for a flashlight)
@oldmantick Yeah, the capacity difference between AA and a D is huge. But the other factor is what kind of a load you’re putting on it. A device that requires a very low load over a long period of time, such as an LED flashlight, would probably work great with these, although it still wouldn’t last as long as a real D cell. The more load you place the battery under, the less time it’s going to last, and some devices which pull a particularly high load might cause the AA to overheat and fail pretty much immediately.
Case in point: I used to have a portable CRT television set that ran off of eight D-cells (12V). When I tried using a similar “battery shell” product with it, the thing turned on, and shut down in less than 5 minutes. When I pulled the shells out the plastic was melting because the batteries had overheated.
@oldmantick What voltage does your NiMH charger deliver to the discharged batteries?
Typical NiMH or NiCad cells are 1.2V.
You can recharge them with a charging voltage that is higher than 1.2V. I’m not sure what voltage the NiBatts are typically charged with, but typical lithiums run at 3.7V and will charge up to 4.2V (before safety features shut off charger). :Insert long explanation here:
To charge lithiums, you typically use about 4.9-5V. :See long-ass safety info:
I never use two flashlights, that take C batteries, that someone bought me at Costco. Yesterday I put them in a box to take to Goodwill. I don’t know if this is worth the money, but I kind of liked those flashlights, so I’ll give it a try. Buying C batteries is a pain in the butt, and I have tons of rechargeable AAs.
True, but how often have you gone to use a C or D battery driven item only to find that the batteries are dead. At least this way you can use the AAs you bought here by the metric shit-ton to run whatever it is.
Battery Converter Shells
Stock up on AA batteries and never worry about buying C or D batteries Battery converters turn AA sized batteries into C & D batteries, eliminating the need to search for different battery sizes and ensuring your devices are powered whenever you need them most
Reduces the weight of the item you are using which is perfect for toys and portable devices Simply open the converter, inserts AA battery, close, and use
Note: We strongly recommend the use of high energy alkaline or nickel metal hydride (nimh) AA batteries within the battery adapter
C Battery Converter Shells: 1.97" Length, 1.03" Diameter
D Battery Converter Shells: 2.42" Length, 1.30" Diameter