How do the unregulated dual 18650 mods work?

[farraz]

I got one its using dual 18650 batteries and fully mechanical... My question is how does the 2 batteries work on it? Does it take both amps from the batteries? volts.. Not sure how it uses the batteries someone please explain thanks

 

[93gc40]

If paralell 2xbattery amps limts, 1xvolts. Allows for lower ohm builds, and longer battery life at same voltage as single battery.

If in series 2xvolts 1xamps.

 

[hadewwken]

Tons of other threads already up to learn about this but in a simple explanation:

Battery play depends on how the unreg box is wired
Series (one Battery positive side up, other positive down) - double the voltage. You're basically stacking batteries and so the mod would be pushing around 7.5-8 volts.
Parallel (both positives up) - pushes a normal voltage output (4.2v), double the mah (battery life), can't tell you much about the amp limit since I've never gotten too into parallel box mods and seen numerous debates on whether the amp limit doubles or not but it does feel safer to fire a .12 build on a mod with two batts compared to a single 18650 mech lol

 

[Hans Wermhat]

If you post a pic of the mod and batteries you will likely get a lot more help.

 

[Boden]

Tons of other threads already up to learn about this but in a simple explanation:

Battery play depends on how the unreg box is wired
Series (one Battery positive side up, other positive down) - double the voltage. You're basically stacking batteries and so the mod would be pushing around 7.5-8 volts.
Parallel (both positives up) - pushes a normal voltage output (4.2v), double the mah (battery life), can't tell you much about the amp limit since I've never gotten too into parallel box mods and seen numerous debates on whether the amp limit doubles or not but it does feel safer to fire a .12 build on a mod with two batts compared to a single 18650 mech lol

For a parallel box the amp limit dosen't quite double unless the batteries have perfectly matched internal resistance. Since most people don't have the equipment to measure the internal resistance of batteries a safe bet is CDR x 1.7.

So two 20A CDR batteries
20A x 1.7 = 34A

How to Measure Internal Resistance

 

[papergoblin]

For a parallel box the amp limit dosen't quite double unless the batteries have perfectly matched internal resistance. Since most people don't have the equipment to measure the internal resistance of batteries a safe bet is CDR x 1.7.

So two 20A CDR batteries
20A x 1.7 = 34A

How to Measure Internal Resistance

^^^^ This and internal resistances can/will change after usage cycles and not exactly evenly.