i attempted and was successful on my first coil build. Was shooting for .2 and ended up with .21. Not too shabby.
First coil build
- Thread starter josh w
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i attempted and was successful on my first coil build. Was shooting for .2 and ended up with .21. Not too shabby.
Nice work Josh
Congrats, don't you feel like you accomplished something. Great feeling on the first one.
Grats.i attempted and was successful on my first coil build. Was shooting for .2 and ended up with .21. Not too shabby.
Specifically, what batteries are you using?
I must comment that 0.2 ohms is pretty low for a beginner to start out on. Considering that resistance is over all currently available batteries' upper CDR spec, leaves absolutely no safe headroom for potential battery failure, and taking for granted that your ohm reader is measuring accurately to tenths and hundreths of an ohm.
Everyone is free to set their own parameters, and I can only say what mine are. I try to never exceed 50% of the CDR (continuous discharge rating) of a fully charged battery (4.2v). So with a 10 amp battery, that 50% would be 5 amps continuous -- a 5.2 amp draw from a 0.8 ohm coil).
Coil amp draw from Ohm's Law calculations:
1.0 ohm = 4.2 amp draw
0.9 ohm = 4.6 amp draw
0.8 ohm = 5.2 amp draw
0.7 ohms = 6 amp draw
0.6 ohms = 7 amp draw
0.5 ohms = 8.4 amp draw
0.4 ohms = 10.5 amp draw
0.3 ohms = 14.0 amp draw
0.2 ohms = 21.0 amp draw
0.1 ohms = 42.0 amp draw
0.0 ohms = dead short = battery goes into thermal runaway
1.0 ohm = 4.2 amp draw
0.9 ohm = 4.6 amp draw
0.8 ohm = 5.2 amp draw
0.7 ohms = 6 amp draw
0.6 ohms = 7 amp draw
0.5 ohms = 8.4 amp draw
0.4 ohms = 10.5 amp draw
0.3 ohms = 14.0 amp draw
0.2 ohms = 21.0 amp draw
0.1 ohms = 42.0 amp draw
0.0 ohms = dead short = battery goes into thermal runaway
The reason that I place a 50% limit is because as a battery ages the mAh of the battery degrades, as the mAh degrades so does the batteries c rating (amp limit). So down the road, your 20A battery may only be a 10A battery. A 30A battery may become only a 15A battery.
You may be placing a lot of faith in a cheap ohm reader in making a precise and accurate reading to a tenth or hundredth of an ohm. The most accurate and recently calibrated digital multimeters can cost over $1000.
A loose post screw holding your coil on your RBA can drastically lower your coil resistance by as much as 0.5 ohms (from personal experience). This is why some safe headroom is recommended.
At the time of this writing (July 2015), there are no mod batteries that can deliver more than 30 amp CDR. Any advertisement of over 30 amps is either marketing hype or a pulse discharge rating (a spec we choose not to use).
You may be placing a lot of faith in a cheap ohm reader in making a precise and accurate reading to a tenth or hundredth of an ohm. The most accurate and recently calibrated digital multimeters can cost over $1000.
A loose post screw holding your coil on your RBA can drastically lower your coil resistance by as much as 0.5 ohms (from personal experience). This is why some safe headroom is recommended.
At the time of this writing (July 2015), there are no mod batteries that can deliver more than 30 amp CDR. Any advertisement of over 30 amps is either marketing hype or a pulse discharge rating (a spec we choose not to use).
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Rofl don't worry I'm not using the coil. I did the wicking wrong and it tasted like burnt cotton lol. I see now why that's not a juice flavor. Anyways I'm back to my .3 atlantis pre made coils and will not attempt another coil build until I recieve my vtc4's. But I think I'll try to stay in the .3 range. It's good enough for me.
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