Are BAK 21700 5000mAh 15A Battery (N21700CG) any good?

@raccoon city, you forgot the fact that it’s sold out :slight_smile:

You made a great choice :slight_smile:

Life is a school, such things happen to all of us.

Awesome.

For once I'm glad that the better item is sold out.

I got 4 of them from there also. Didn’t have any problems. Can’t use them for hot-rods.

Bak stuff is decent.
I would use them if i didnt have tesla model 3 packs to tear down for cells.
Last year a regular bought a bunch of the bak 5000mah 21700 for me to put in his harmon kardon speakers.
A cycle a day since and no capacity fade noted.

I decided to switch from Samsung 30s over to Molicel 4,200 mah 45 Amps. Not quite up there with 5,000 but much better runtime for my lights and noticeable increase in power

less internal resistance on the lower capacity cell. this is why finding the right battery for your application is so important.
i use a 5000mAh battery, but only draw 500mA of current most of the time, and 1A at most.

That’s really interesting I didn’t know that

Can you elaborate more on “this is why finding the right battery for your application is so important.” for me please?

Ive raised concerns here and there a few times, about not understanding whether a certain cell and flashlight are an “appropriate combination”.
I basically just get told to not really worry about it.

i’ll try. note, i’m not an engineer or an expert in anything.

first you need to know how many Amps are drawn on the battery, not on the Emmitter leads for the light in question.
then i suggest looking at battery capacity curves at different currents. you may find you get more capacity with a lower mAh cell at a given load.
some want the highest output and least voltage drop from a cell when fully charged and capacity be dammed.
also, MANY cell ‘manufacturers’ and re-wrappers lie about Amp, and capacity ratings.

the two places i use that in my opinion are very reputable for battery test data.

Mooch (AKA Battery Mooch on youtube) his content is aimed at batteries for Vape Mods etc, but his testing is thorough and relevant to us.
make sure you read his notes when he tests cells.
https://www.e-cigarette-forum.com/blogs/mooch.256958/

HKJ (from EEVblog)
https://lygte-info.dk/info/indexBatteriesAndChargers%20UK.html

i really like Mooch’s approach and showing just how many companies and re-wrappers lie about ratings.
you should check him out on youtube. very informative about choosing the right cells.

or, you could ‘not worry about it’

CG battery is good,equal to 50E-2

@Dudeman
Thank you.
I’ve clearly been using my lights like a moron this whole time.
I don’t know anything about electricity let alone taking it that far.
I no longer feel safe using these lights/cells. And probably never should have been in the first place being so uneducated. Thanks for possibly saving my life and others. Or at least from wasting any more money.

The dude is not saving your life and is being overly dramatic. I can’t stand clearly unknowledgeable people trying to “guide” and overwhelm other unknowledgeable people.

Batteries are perfectly safe as long as you just use common sense. If the flashlight is too hot to hold, just ramp down. Most of the lights for enthusiasts do this automatically.

Discharge rates don’t matter much other than the fact you might not get max performance on your lights. A low discharge cell might get a bit hot but the flashlight will ramp down well before reaching any unsafe limits (80C+). The flashlight heatsinking ability is almost always the limiting factor.

One of the only dangerous situations an enthusiast may encounter is not locking out a powerful light in a bag or something.

Look it this way, Li-ion batteries are everywhere including phones, laptops, electric bikes, etc… How many people know anything about their batteries or how to take care of them?

1 Thank

I was pretty overwhelmed at the time of writing that. Regret it now but not deleting it.
I have been reassured by many people now that my worries are misguided and Im overly concerned about non issues.
I have had a lot of misunderstandings lead me astray regarding lithium ion cells over the last coupl years.
Im getting there. I love my flashlights.
Thank you for your input as well.

My appologies to BLF at large for being very over dramatic at times.
Ive chilled out a bit agan.

fogofwar is 100% correct!

Glad to see you have “chilled out” a bit CRC2, now stay that way & enjoy using your lights. :wink:

No worries, I was actually saying that the other commenter was being a bit overdramatic implying that you’ll burn down your house or something if you don’t understand discharge rates. But you were also a bit dramatic :wink:

Enjoy your flashlights!

Well this BAK N21700CG looks like an interesting 15A cell. Thanks for this RC :+1:

I will soon permanently make transfer from 18650 to 21700 format in my flashlight builds and unfortunately I’ll have to say goodbye to my most trustworthy cell Samsung INR1865030Q.

P.S.
Is there anything on the market that could be cheaper than mentioned BAK N21700CG which costs about 3$ per cell?

To reply again. About month ago I took small order of 250 pcs BAK N21700CG battery from reputable NKON intended for mine 1x 21700 flashlights.
Each and every one of them are on the same charge voltage(3.5V), they are much more powerful than Samsung INR1865030Q giving better and longer constant performance/longer runtime/better brightness with FET drivers even though they have greater stated internal resistance than INR30Q?! Don’t know how that is possible but it is. They are so good that I will have to de-tune FET driver setup (removing bypasses here or there). Very cleverly spent 4$! China manufacturer nailed with this one :+1:

1 Thank

That reminds me…
The next time that Lishen or BAK has their 5000mAh 21700 cells on sale, I need to get some. :slightly_smiling_face:

BAK is a really big battery manufacturer in China along with Lishen and PLB. They make good low cost cells for a lot of OEMs worldwide (find them in Sofirn/Wurkkos, Astrolux and Mateminco, Trustfire, Fireflies, and other small brands) but you probably won’t encounter them in any products for mainstream consumer use here in the USA.