So as I am watching TV I see an infomercial about this new product called the “Jump up”. It’s a series of colored shells that lets you use smaller sized batteries (Say, a AAA) into a slot designated for a bigger battery (a AA). Would this actually work? The Jump up product never seemed to be anything more than just a shell with a coil in it. You literally seem to use the AAA battery’s power in place of the AA. They also said that you can combine the shells and use a AAA battery in place of a D!
I’m assuming it has to work somehow since they’ve marketed it and put the product out…but how does it work? Aren’t batteries different sizes for a reason? If not, than why do we even have different sized batteries? I was always under the impression that the different sized batteries meant different voltages for different products…but I guess not. So please dopers educate me on batteries so that I may be ignorant no longer
AAA, AA, C, D are all nominal 1.5V. The larger cells have a larger capacity and lower internal resistance, which means that they can put out more current or last longer for the same current. Expect reduced battery life.
It works fine, I have a Sanyo Eneloop (neat batteries by the way) set that has battery cases to adapt AA batteries to C and D sizes. As pericynthion said, battery life from the AA batteries in a C or D cell device will be less though.
It will work – to a degree and for a while. While AAA, AA, C, & D cells all have the same voltage, they have different total energy capacity. The smaller battery won’t do the job as long as the larger one, and in some cases (e.g. running a motor that moves something against resistance) won’t do it as quickly or maybe at all.
So if you’ve got some AAA’s on hand, you can use this product to avoid having to go out and buy AA’s for your flashlight. It could be seen as a convenience in a pinch.
Or it could be seen as paying money for the privilege of increasing your total battery expense because you’re too lazy/disorganized/stupid to get the right ones.
these allow a smaller battery to fit in a space made for a larger battery.
a AAA battery might power a device made for a AA battery for a fair amount of time.
a AA or AAA battery might power a device made for a D battery for minutes or not at all because it demands far more current than the battery can supply.
just because something is for sale or marketed heavily doesn’t mean it works well. it may only be a good product in the fantasies of the marketing department.
I will qualify my previous response to state that I’ve never heard of “Jump Up”, just the Sanyo Eneloop kit that seems to do the same thing. As long as Jump Up is decently constructed it should work in theory, with the caveats mentioned above.
a note that if you find rechargeable “C” or “D” cells in a store, they are nearly always “AA” cells in not-easily-removable plastic cases like these to adapt them up to the larger size.
What’s the business model for this premise? That a AAA battery is cheaper than a AA, and that 3 AA batteries are cheaper than one D. Or that larger batteries are harder to find?
Seems like a stupid idea. Different size batteries are cheap and easy to find.
as for selling these adapters, I think a lot of it is “hey, need a C or D battery but don’t/can’t get to the store? These’ll help you in a pinch.”
For the ones I mention sold inside adapters, I guess part of it is that the consumer demand for C and D cells is shrinking; time was that things like portable radios and TVs needed the capacity of D cells but now those things either have an on-board rechargeable lithium battery or use AAs.
I wouldn’ t be surprised if D cells are primarily sold for flashlights these days, and you’re not going to want to use rechargeables for those anyway due to the self-discharge.
you can find proper C and D NiMH cells if you look around (they should be 10000-14000 mAh capacity) but they’re expensive due to low demand.
This concept of using smaller batteries to work where a bigger battery was intended became popular or more popular when high energy density batteries became available.
The voltage on these small batteries is the same, 1.5VDC, except rechargeables are 1.2VDC. The small rechargeables were still able to supply the current needed to make devices work that used bigger batteries. There is a limit to the concept. It works in a radio, clock, or other device with a small current draw. Those batteries run short of power when higher demands are necessary. Also, they run down sooner because the total ampere hours available are limited.
Personally, I like the right sized battery in the maximum available ampere hours available in the rechargeable form when possible. Alkaline batteries hold their charge for years and are therefore handy to keep around for emergencies. I take pictures every day and always like to carry some alkaline cells just in case the rechargeables run out.
Oh I’m sure, but I don’t think people are buying as many as back in the day. I think most applications for large cells now are “Emergency” things like flashlights and stuff. Alkaline C and Ds are ok for this 'cos they’ll last on the shelf for a long time; dry cells will last practically forever on the shelf but their current output and internal resistance are crap.
I saw these years ago. As noted by others, rechargeables may be actually be very small, so you could keep a set of AA rechargeables and use these devices for compatability. But personally it’s never been worth the effort to use rechargeables or anything like these devices.
