18650 vs 18650B?

What is the difference in 18650 and 18650B.

Plan to use in Convoy S2+.

Is there a valid difference in brands?

Looking for long(ish) run time. Used for tracking and can take 2-4 hrs.

taz-d said:

What is the difference in 18650 and 18650B.

Plan to use in Convoy S2+.

Is there a valid difference in brands?

Looking for long(ish) run time. Used for tracking and can take 2-4 hrs.

Click to expand...

Well, specifically, the 18650 denotes a li-ion cell that is 18mm wide, 65mm long and 0 means cylindrical (or as some state, rechargeable.)

They are normally a 3.6v/3.7v nominal (~50% charged) and charge up to 4.20v hot off the charger.

Panasonic is a manufacturer of 18650s and their progression in development was the NCR18650, which was a lithium-cobalt based cell (ICR) and 2900mAh in capacity. Next up, was the NCR18650A, which had less cobalt and was 3100mAh in capacity. Then they moved to the NCR18650B, which was 3400mAh and lastly, we have their NCR18650G, which eked out 3600mAh.

Other manufacturers like Sanyo (now owned by Panasonic,) Sony, LG and Samsung all make 18650s and have their own model numbers.

The chemistries have changed to hybrids, using all sorts of metals/chemicals. It used to be that you could have high current handling and lower capacities (IMR: usually for tool packs,) or you could have higher capacities and lower current handling: the NCR18650A/B.

Now with the hybrids, we have something like the Sanyo-Panasonic NCR18650GA, which has both 3500mAh of capacity (pretty high) AND higher current handling (10A,) so we get the best of both worlds right now.

Still, if you need really high current handling--15A-30A, we have 18650s like the Samsung 30Q, 25S, the Sony VTC-5, 5A and 6. LG makes some cells capable of 15A+ (HG/HE 2,) so look to that brand.

The above comprise the Big 5 for 18650s and are to be sought after. These cells all come from their respective factories with flat tops (vs. button tops) and without any added protection circuits (PCBs,) so if you see either of those, they've been added by a 3rd party vendor.

Chris

Thank you.... Big help.

In addition to the above excellent info from Chris, I would say to avoid any light that has "Fire" at the end; they have been counterfeited by many many types(I have seen a Cr123 cell wrapped to look like an Ultr*fire 18650 and sawdust added as a filler). The other sage advice from many CPFr's is to only buy from a reputable source(Mountain Electronics, IMR Batteries, Illumin and Battery Junction to name a few)...

That post from Chris should be a sticky. I for one, am saving it.
P

Ordered the Panasonic NCR18650B.

Thanks.

taz-d said:

Ordered the Panasonic NCR18650B.

Thanks.

Click to expand...

I've got 3 S2+ lights and 4 other Convoys (M1, M2, C8, S2) and all of them, save for an S2+ Triple custom that Ven got me, have the 8x7135 2.8A driver boards and the NCR-B should be fine for your light. It can handle the ~3A current and it's got good capacity.

Good luck.

Chris