Understanding the Samsung 30q

When I first put my Samsung INR18650 30Q in the charger (a LiitoKala Lii-PD4) it’s charging at
500mA and on the left it reads Li-ion-3.70v
When I first put the battery in I have an options to switch it to Li-ion-3.80v
What is the difference in the voltage? When charging.
When I do switch it to 3.80 V the percentage that the battery has been charged drops.

The 3.8V setting is for batteries intended to be charged to 4.35V. The 30Q is intended to be charged to 4.2V, for which the 3.7V setting is appropriate. Overcharging the battery will significantly reduce its service life.

Yup, as Zak mentioned, the difference is the termination voltage. If you choose “3.70V”, the cell will terminate at 4.2V. If you choose “3.80V”, the cell will terminate at 4.35V.

You want the “3.70V” setting for your 30Q cells.

Thanks guys I appreciate it I’m new at this just starting to learn. These batteries came with my blf A6 spec Edition flashlights.
Another question, if the A6 has come with double tail cap springs do I need to do the spring bypass mod. I’m guessing yes because I did one and it is noticeably brighter, side-by-side with another one with the same batteries, both fully charged straight out of the charger.
And what gauge copper wire are you using for the spring bypass mod?

The A6 does not need a spring bypass, but I expect it will be brighter afterward, even with a double-spring design. I use 3mm desoldering braid for bypasses, usually.

I know this is a loaded question,but.
Why don’t the manufacturers do this if it makes a better Connection?
Or is that the 64 million dollar question.

Concerning the A6 would a spring bypass on the front spring make for a better connection and brighter light?
Is there an advantage to doing both front and rear spring bypass?

More labor, and most people don’t care. 100 lumens here or there won’t make a noticeable difference on the A6.

If you think about manufacturing something like a flashlight, you can imagine that soldering little wires to the insides of both springs adds labor and cost to the production. If doing so offers an important advantage in lumen output over a competitor, it might be worth it; otherwise, it’s not.

Doing both bypasses gave another 200 lumen on the original-production light, but that light did not have a dual-spring tail. Your light may already achieve near its maximum output.

If I’m going to do a bypass, I’ll try to do both springs. However, my current-production A6 came with two springs on the tail, so I feel no need to mod it. If you do, the best approach is probably to remove the inner spring and put the bypass wire through the PCB to the switch. That’s a lot of hassle for little gain, though.

The A6/A1 only does Turbo for 45 seconds and can get very hot if you keep re-activating Turbo, so at some point you’re better off modding a different light. A C8 can absorb more heat and the larger head is easier to mod. Just sayin’ :wink: .

I’m all in favor of modding your light, however, as that’s a large part of that BLF is about. A look through the forum history will show that members were often squeezing every possible lumen out of $15 lights. I encourage anyone to keep that tradition alive :beer: .

Also see:

You know what’s better than an A6?
6 A6’s
I got 3 black anodized and 3 non anodized, I love this light !!!