Where to buy 18650 battery

[zahc]

I have bike lights that use 18650 but I only have 1 nitecore battery. Amazon is full of random generic batteries and even if I bought a name brand from them I would suspect counterfeit. So do you just buy the cheapest thing, or if not how do you buy a good protected 18650 online, while knowing what cell you are getting, without getting ripped off?

[charby]

Sometimes you need to get away from the keyboard and goto a storefront like Interstate Batteries.

[Fly320s]

I don't think you can guarantee that the battery won't be counterfeit, unless you buy it directly from the manufacturer.

Why don't the big name companies, Duracell, Energizer, etc., make the 18650 battery?

[K Frame]

I've had good experiences with BatteryJunction.com

[RocketMan]

Our own member Calumus recommended RTD Vapor for batteries.  They sell a wide range of 18650 batteries, and all are genuine.  Calumus buys his batteries from them.  I've purchased some Samsung units from them to rebuild cordless drill battery packs.  The customer service was good.
However, if you do choose to buy from RTD Vapor, you'll need to do so soon.  He is getting out of the battery business by the end of the year due to increasing costs.

[zxcvbob]

I've had good luck with RTDelectronix (no longer in business) and RTDvapor (same folks, still in business) and illumn.com.  You can also get 18650 unprotected flattop cells out of old laptop batteries.  I have a quart jar full of those; almost as good as new cells, and better than new off-brands and forgeries.

I also really like my XTAR VC4 battery charger.  It will charge a mix of one to four NiCd, NiMH, and lithium batteries all at the same time and charges them independently.  It's good for identifying the good cells from the bad one in scavenged batteries.

[zahc]

Gotta say these things are pretty intriguing, especially for camping or travel where I could recharge them off my cell phone charger.

https://www.amazon.com/dp/B085DV7VZK/ref=cm_sw_r_cp_apa_fabc_tt3PFbPDMVX7F

[Calumus]

I've had good luck with RTDelectronix (no longer in business) and RTDvapor (same folks, still in business)

I also really like my XTAR VC4 battery charger.  It will charge a mix of one to four NiCd, NiMH, and lithium batteries all at the same time and charges them independently.  It's good for identifying the good cells from the bad one in scavenged batteries.

He's a client of mine. The electronix site was only put up when PayPal started blocking sales of vape products. Apparently 18650's for mods are bad; but 18650's for flashlights are OK... I just picked up a VC4 from him. He says it's far and away his most reliable charger. He's sold thousands, and only had a handful come back.

[MechAg94]

https://www.batteryjunction.com/

I have used this site.

[Kingcreek]

Another satisfied battery junction customer here. I’ve made quite a few purchases there.

[Northwoods]

Wrecked Tesla?

[Silver Bullet]

Battery Junction for me.  Big shipping charges, but free if I buy at least $50 worth, which is never a problem I just stock up on AA and AAA when I buy something else.  Very good prices, too, when you are buying 36 or 48 AA at a time.

[AJ Dual]

Will a flat-top 18650 work in your bike light, or do you need a button top? Also, it matters what kind of driver circuit the light has, will it cut out/off after it reaches a certain drain voltage?

Because I've had excellent results with Panasonic, Samsung, and LG brand 18650's. They're meant more for laptops and battery pack applications where they're all spot welded onto bus bars, but if your device has contacts/springs that can reach the battery without a bump/button on the positive end, these are all the performance for a fraction of the price.

The downside of course is these cells for $3.45-$5.00 don't have a bi-metal protection cutoff switch in them. They're meant to be used with a charge controller that watches things.

And many/most of the other brands are just re-branded Panasonics, Samsung, and LG's anyway.

Stay away from Ultrafire. I don't think they'll blow up, but capacities in mAh are way over reported.

[zxcvbob]

For one of my better flashlights, to use flattop batteries I had to make a little adapter.  It's a circle (I guess 18mm diameter) cut from an old credit card.  I put a small roundhead paper fastener (brad) in the center.  It's a single-battery flashlight so I don't worry about reverse-charging.  And I don't run the battery all the way down before recharging.  The Chinese knockoff flashlight doesn't need the adapter because it has spring terminals.

[zahc]

This is the light. I'm not sure if it requires button top or if it requires protected cells. The single 18650 it came with is a protected button top cell FWIW.

https://www.amazon.com/dp/B015NMH16U/ref=cm_sw_r_cp_apa_fabc_j8yQFb1ZJ17YN?_encoding=UTF8&psc=1