Battery position on a mech
- Thread starter Jackvape
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Shetland Sam
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I always put the positive towards the vent holes.
speedfreek67
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There are many aspects to this.
Firstly, there is the need to understand what battery orientation does, in terms of current flow.
With positive up, the pin in your atty is positive, whilst the outside of the battery, the body of the atty and the body/switch of the mech is negative.
If there were some small unseen damage to your battery wrap, and the side of the battery made contact with the inside surface of your mech tube, it would complete the circuit, cause current to flow and your mech would auto-fire.
If your build is well within the safety limit of the battery, this shouldn't cause too much of a problem, and is easily noticed.
If you put positive down, now the pin in your atty is negative, the outside of the battery is *negative*, the body of the atty and the body/switch of the mech is positive.
If there were damage to your battery wrap and the side of the battery made contact with the inside wall of the mech, nothing would happen until you press the button to complete the circuit...
...BUT... The circuit would bypass the atty, causing a short circuit between the outside of the battery, the inside of the mech and down through the switch! This is a hard short circuit, bypassing your build, with only the resistance of the body of the mech and the switch. Very very dangerous indeed, instantly causing your battery to overheat and possibly explode very quickly in a process called thermal runaway.
Now some mechs have an insulating sleeve inside to prevent that kind of internal short circuit. In these there is generally considered to be no danger of that battery positive down scenario.
But there is always the question of venting holes to consider too. Are they at the top, or the bottom?
Batteries tend to vent from the positive end.
If a battery gradually overheats and vents, say due to an unnoticed auto-fire, then there is not enough pressure from venting gasses to cause your mech to explode, even if the battery swells up. So I would go positive up in a tube with no inner sleeve, even if the vent holes are at the bottom.
And vent holes aren't enough to stop your mech turning into a pipe bomb in the event of thermal runaway anyway, so in my opinion that is the most important scenario to avoid.
Always scrupulously check your battery wraps!
Firstly, there is the need to understand what battery orientation does, in terms of current flow.
With positive up, the pin in your atty is positive, whilst the outside of the battery, the body of the atty and the body/switch of the mech is negative.
If there were some small unseen damage to your battery wrap, and the side of the battery made contact with the inside surface of your mech tube, it would complete the circuit, cause current to flow and your mech would auto-fire.
If your build is well within the safety limit of the battery, this shouldn't cause too much of a problem, and is easily noticed.
If you put positive down, now the pin in your atty is negative, the outside of the battery is *negative*, the body of the atty and the body/switch of the mech is positive.
If there were damage to your battery wrap and the side of the battery made contact with the inside wall of the mech, nothing would happen until you press the button to complete the circuit...
...BUT... The circuit would bypass the atty, causing a short circuit between the outside of the battery, the inside of the mech and down through the switch! This is a hard short circuit, bypassing your build, with only the resistance of the body of the mech and the switch. Very very dangerous indeed, instantly causing your battery to overheat and possibly explode very quickly in a process called thermal runaway.
Now some mechs have an insulating sleeve inside to prevent that kind of internal short circuit. In these there is generally considered to be no danger of that battery positive down scenario.
But there is always the question of venting holes to consider too. Are they at the top, or the bottom?
Batteries tend to vent from the positive end.
If a battery gradually overheats and vents, say due to an unnoticed auto-fire, then there is not enough pressure from venting gasses to cause your mech to explode, even if the battery swells up. So I would go positive up in a tube with no inner sleeve, even if the vent holes are at the bottom.
And vent holes aren't enough to stop your mech turning into a pipe bomb in the event of thermal runaway anyway, so in my opinion that is the most important scenario to avoid.
Always scrupulously check your battery wraps!
Last edited:
Vapaneezer Scrooge
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papaeff786
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Seeing this info always makes me feel safer using the battery positive up
vapesmarter
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100% @Mitz , for me it's always positive up, I'd rather deal with autofire than a hard short any day, avoids the brown pants syndrome
EDIT: Unless there's a liner.
So your saying positive to the 510 ?
As in up
On a mech pipe it’s positive down as in positive to the positive pin ?
D
Deleted member 54254
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I can't speak to pipes @vapesmarter , I've never seen one to understand how the circuit works 
I did preface my sentence with - for me... no doubt others might see it differently but I'm just an old paranoid wreck. There's a few mech's I've passed over due to their design.
I did preface my sentence with - for me... no doubt others might see it differently but I'm just an old paranoid wreck. There's a few mech's I've passed over due to their design.
speedfreek67
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Yeah, if we are talking about a battery tube without an insulating sleeve, in the event of unseen damage to the battery wrap there is the possibility of the negative battery casing shorting against the inside of the battery tube.
In that scenario, battery positive to positive pin would cause an auto-fire, whereas battery positive to switch would cause a hard short when the switch is pressed.
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