Noob battery questions

ok....new guy here....feel free to flame away. Have been searching for something to explain different batteries, types, what fits what..... haven't found much. so here goes....
I have two chargers....a NiteCore D2 and an Eneloop with Panasonic charger. Not sure why I bought these other than I have a dozen rather inexpensive (less than $15-20) lights. I know I have an 18650 in one of these. I guess my questions are:
what do the 18650 replace? what to the 14xxx replace? what to the16xxx replace? What do the cr123 replae?
Why do I have nimh batteries? what is the "common" rechargeable battery? Are these white eneloop good rechargeable batteries?? Are the nimh good for flashlight or other ues?
I don't know much about this, trying to learn. I appreciate your input.

Not sure where to start with this question, asking "what do the 18650 replace" doesn't make much sense as is. Your devices will require a specific type/size/voltage battery, so you use in this device whatever battery it expects.

18650 is a Li-Ion technology battery, the chemistry used. Li-Ion batteries are named after their size, so 18650 means 18mm diameter, 650mm length, 14xxx means 14mm diameter xxx length etc. There are a couple of variations of the Li-Ion technology, the most common type has a nominal voltage of 3.6V (max at 4.2V), others max out at 3.6V (nominal 3.2V) or 4.35V (nominal 3.7V) so take special care on what battery to pick for your device and also what is supported by your charger. Always refer to your device on what type of chemistry/voltage it accepts otherwise you risk a burnt device or even worse a fire hazard.

CR123A is again a lithium battery, NON-RECHARGEABLE!!!!!! Take note on this, do not attempt to charge a non-rechargeable battery. Nominal voltage is 3.0V and max at about 3.2V I think. RCR123 is the rechargeable version of this battery (LiFePO4 technology) which is one of the Li-ion variations (max at 3.6V) but again usage depends on what your device can accept.

Please educate yourself on Li-ion especially before messing with these. There is tons of information on these batteries at CPF and elsewhere so take your time to understand what is what and how to handle them. The biggest issues arise from overcharging/overdischarging these batteries or use a battery that can't deliver the requested current of your device (like vaping equipment, you have to use a capable battery, not all are created equal).

NiMH is a replacement for the alkaline batteries in AA/AAA/C/D sizes and has a nominal voltage of 1.2V. NiMH is good for everything that takes such a size inside, it is actually much better than alkalines at power-hungry devices.The best battery so far is the eneloop/panasonic brand. There is a small posibility some quite older devices may have issues with the voltage offered by NiMH but this is mostly due to poor device design. NiMH is much much safer to use than Li-Ion, the most it can happen is to ruin your battery really.

Yes, basically your AAA size is 10440(3.6 or 3.7v nominal ,which is 4.2v fully charged). AA size is 14500(again 3.7v) CR123a is 16340(3.7v). For example, if your light used 2xCR123, then a rough size to use would be 16650. Now many single 18650 lights will accept 2x CR123 cells in its place(3v+3v=6v). However, again most will not support 2x16340 cells as fully charged you have 8.4v(4.2v+4.2v)

Yes the white eneloops are excellent, so are the pro versions (black wrap).

As said , be cautious on what cells your using if the light is running AA cells, as most will not support 3.7v cells. You can check by checking manufacturers specs or asking on here if not sure. Dont take any risks basically or you could end up with a paper weight.

18650 means 18mm diameter, 650mm length

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18650 is 65 mm in length, not 650.

And both AAs and AAAs are rated at 1.5v, so a one-in-series (1s) 18650 should suffice for a 3s AA/AAA low-draw application. Many cheap LED flashlights use 3s AAA, which can sometimes be easily modified to take a single 18650.

Yes the 0 on the end is for cylindrical , ironically the 65mm cells tend to be 66mm and over. Add protection / button tops and you can even see past 70mm, however 18650 cells do not come with PCB's from the factory. These are added later on by manufacturers along with button tops. PCB's depending are not perfect either, ones with the strip down the side can be shorted out by catching the flashlight tube . They can also give a false sense of security and users may rely on them when low voltage. Increased length can also be a problem, potentially damaging the top/bottom of the cell along with the flashlight.

Its certainly worth researching the light, finding out the best suited cell for it. Many lights today have LVP(low voltage protection) and some will trip the PCB on higher/turbo levels . The zebralight being one example where the manufacturer recommends sanyo GA flat tops. As the light asks around 8a(now you can get protected cells with higher rating), the GA and other flat top high drain cells work well. The manufacturer took advantage of this and made their models even more compact. Some dont like this, would prefer a few mm longer to allow more cell choice. I digress, but just an example where protected cells wont fit! or may trip depending.

ven said:

Yes the 0 on the end is for cylindrical

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No, it is because it is 650 tents of a mm long.
The R in ICR/IMR/INR is for round cell.

Thanks for the correction HKJ, i am sure i read for cylindrical/round in the past.

ven said:

i am sure i read for cylindrical/round in the past.

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I have seen that misunderstanding repeated many times. The meaning of the letters and numbers is defined in a standard and that standard says tents of mm.

:thumbsup:

HKJ said:

I have seen that misunderstanding repeated many times. The meaning of the letters and numbers is defined in a standard and that standard says tents of mm.

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Shouldn't it be a 180650, if they measure in tenths?

xxo said:

Shouldn't it be a 180650, if they measure in tenths?

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It is only the length that is measured in tents.
It is exactly same way button cells are specified, except the length has on less digit. A CR2032 is 20mm in diameter and 3.2mm thick and the R says it is round.

HKJ said:

It is only the length that is measured in tents.
It is exactly same way button cells are specified, except the length has on less digit. A CR2032 is 20mm in diameter and 3.2mm thick and the R says it is round.

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Thanks!



That makes sense, they are using the same system originally used for "watch batteries".

For reference, below is a summary of IEC battery nomenclature

You've already gotten some great responses on battery and battery charging use and safety, so I'll just add a quick comment of my own.

Based on what I've read here on CPF for several years, and also following people's experiences on the vaping websites (where "hot rodding" certain kinds of high draw vaping devices is common), most of the accidents seem to be where someone did a quick charge, and then immediately put the battery into a high draw application, without allowing the battery a "rest period," and some time to cool down before use.

Now this is just my anecdotal impression, and I'm sure there are more objective statistics on this somewhere. Of course, certain chemistries are more tolerant of abuse than others. I'm assuming most of these incidents involved lithium cobalt oxide types, but that's just an educated guess.

In any case, learning about and following proper battery and battery charging procedures and "discipline" is a very good idea when getting into serious or demanding lithium ion battery applications, or even casual not so demanding ones that are unlikely to stress the battery.