EBL C Size Battery Adapters, AA to C Size Battery Spacer Converter Case Use with Rechargeable AA Cells - 4 Pack

Found these after I had already found d some cheaper clamshell style clear ones found all over. These are way better with the fit of the inner battery, no rattling around. Keep in mind, unlike a real D battery or the clamshell style adapter that has its own larger negative contact area , these use only the inserted AA battery negative contact area anticipating the contact of the small nub from the positive side of another battery or adapter. This may not be an issue for your purpose but for mine, use in a D battery Maglite, these only work for the first inserted batteries. I have to use a real battery as the final battery because the Maglites cap spring is what contacts the negative battery contact area, has an inner diameter that is bigger than the outer diameter of the AA battery negative contact area.

About battery cell adapters..... Adapters such as these are simply a sleeve to center an AA cell in a compartment sized for a larger C cell. In order to work, the contacts on the device must be able to meet with the smaller diameter ends of an AA cell. Several other reviewers mention this. With an AA cell in hand, you can generally "eyeball" whether this will work by inspection before purchasing. For spring loaded devices, pushing in the adapter with its AA cell will sometimes result in the AA cell pushing through the sleeve. With multiple cells end to end, this can be a frustrating task. This can sometimes be corrected by wrapping some tape around the AA cell to increase the friction. If you can get this system to work, there are other considerations. An AA cell usually can't provide the amperage of a C cell so, some devices may deliver neither the brightness nor volume, etc. expected. Other devices may not work properly at all. Also, an AA cell can't provide the amp-hours that a C cell does thus, operating times may be shorter. I use these adapters with non-rechargeable Lithium AA cells (or, AAA cells, see below) in my seldom used equipment such as an emergency radio or lighted precision reticle since the Lithium cells are less prone to leakage, over time, than alkali batteries are, and, to my knowledge, are not available in C size yet. It seems the non-rechargeables are only available in AA, AAA, and 9v. That's where these are a good workaround. Another alternative is this adapter which I have also used. https://www.amazon.com/dp/B0851DLJ3T?ref=ppx_yo2ov_dt_b_fed_asin_title Here a combination of multiple AAA cells can be used (in parallel) to replace a C cell in many cases equaling, or exceeding, the C cell's original capacity. While contact alignment is not generally the issue, size may be. If the device using C cell compartment is tight from a diameter perspective, sometimes these adapters, with a full capacity of 4 AAA cells, will not fit or, will get jammed and difficult to remove. These adapters also introduce a third metal to the circuit. There is now the additional risk that different metals in contact with each other (essentially forming a "battery" in their own right) will begin an electrochemical reaction resulting in oxidative corrosion. Again, your mileage will vary. Both of these adapters have their function and purpose. They may well work for you. Hope this helps.

I have these in the D size, the sea size just didn't seem to work in the product I have, the batteries kept popping out of the holders so I couldn't use it. Had no problems with returns, I would have kept if it would have been in a different product Maybe. Can't really complain, as I said I have some in a different size but I just couldn't use these particular ones.

These are pretty basic, a plastic sleeve that slips over an AA size battery so they fit in place of a C battery. They work flawlessly in this regard, with the AA battery fitting inside snugly. The plastic feels strong, not like it will crush or fall apart easily, so I expect they should last a long time. They're working well for allowing me to use AA NiMH batteries in an old radio that takes C batteries, resulting in my not having to have specific batteries and a charger just for that radio. Well worth the price for that convenience.

I have two devices that use C batteries, and neither of them use much power. I didn't want to have to buy C batteries just for these two devices, so these adapters work great. You can just keep them in the device and swap out the AA batteries when it needs to be changed.

These might be usable for some applications, but they have a flaw that makes them useless for most. These are a plastic shell that you insert an AA battery into. This pushes the adapter's positive contact into position. If the battery is not fully seated, the positive will not reach the device's contact, so will not supply power. There is nothing but friction holding the battery in, so as you put these in the device, one wrong move means the battery slips out of position. Since I need to pull these out frequently to recharge, each time it's a struggle to install all four without at least one not working. So, stars added because they can work, but a couple off because they are so finicky.

Great tool! Especially in an emergency.

Awesome idea repeated buyer A+

他の方の投稿にもありましたが、単三のマイナス極のさいずになるので、単一用の電池ボックスに収めると、マイナス極に接触せず通電出来ない事があります。私の場合、ガスコンロの電池切れでこのアダプタを使用しましたが、マイナス極のバネ状の金属に触れず通電しませんでした。試しに二本入れるうちマイナス極側に電池切れした元の単一、プラス許可側にこのアダプタをつけた単三を入れたところ通電し、アダプタ自体は正常に通電することを確認しました。ほかのかたのとうこうのとおり、マイナス極側に1円を入れ、接地面を大きくしたところ、2本ともアダプタ付きの単三を入れても正常に通電するようになりました。

加工が甘いので、電池が引っかかる場合があります（3/4個）。 凸部の接地面が非常に狭いので、使用先の端子が完全に平面である必要があります。

通電しません 絶対に買うのをやめましょう

単一と単3が一対一で使えるので便利たが、 単3を入れるとアダプターのプラス突起が スライドして出っ張り、ロックされる仕組みだが、ロックが弱いためアダプターをセットする際、マイナス側がスプリングで押される前に プラスの突起を当ててしまうとロックが外れて 突起が引っ込み、接触不良となるので注意が必要。

単3の充電池で、単1用の器具が使えるので便利です。ちゃんと使えて、しかも安い。ありがたい商品です。