Keystone battery holder fix

[VapingBad]

Pimped my Keystone sled with a 4 mm brass screw, some circuit board fibre glass, a spring, a copper contact from an old flash light and some epoxy. Could be better especially the spring, but a lot better than the standard contacts.



I was asked why on ECF, here is my answer

I am getting lower sag in EScribe as the standard connections have less electrical admittance and yes fewer weak battery warnings. The standard connections can also rip the shrink wrap, are made from thin metal I think was chosen for it's springiness and you only need 1 spring not 2. This is more like when they realised the spring should not be a conductor with 510s and started making decent sprung 510s, plus a better contact area.

It is common with vape parts, partly a brand name thing and partly a lot of mod makers & mod making supply stores choose the thing that's easiest and quickest to fit. Like probably the most popular sprung 510 they seem to trust in the name and don't actually address performance and reliability.

All IMHO

[VapingBad]

More people are realising how poor these sleds are in > 30 W e-cigarettes now they are building DNA 75s with as you can see the voltage sag on there PC. It is not that they are bad for other applications or it's just this brand, just that they not fit for today's e-cigs IMO, even the cheap $30 mods have much better battery connections these days.

evolvapor.forumchitchat.com/post/battery-sleds-8125802

[Greg]

I'd think conductance would be a more appropriate term than admittance for such a connection

[VapingBad]

May 28, 2016 15:34:53 GMT Greg said:

I'd think conductance would be a more appropriate term than admittance for such a connection

Admittance is the more commonly used electronic engineering term and applicable to both AC and DC, but it's six of one and half a dozen of the other I guess you are thinking that just because conductance is only used in DC it is more apt. 

[Greg]

May 28, 2016 15:52:06 GMT VapingBad said:

May 28, 2016 15:34:53 GMT Greg said:

I'd think conductance would be a more appropriate term than admittance for such a connection

Admittance is the more commonly used electronic engineering term and applicable to both AC and DC, but it's six of one and half a dozen of the other I guess you are thinking that just because conductance is only used in DC it is more apt. 

No I think admittance is AC only and it's made up of a combination of conductance and suseptance, the latter doesn't occur in a DC circuit hence why I suggested conductance to be more appropriate although I could have omitted the more  Tease-smiley

[VapingBad]

May 28, 2016 15:57:47 GMT Greg said:

May 28, 2016 15:52:06 GMT VapingBad said:

Admittance is the more commonly used electronic engineering term and applicable to both AC and DC, but it's six of one and half a dozen of the other I guess you are thinking that just because conductance is only used in DC it is more apt. 

No I think admittance is AC only and it's made up of a combination of conductance and suseptance, the latter doesn't occur in a DC circuit hence why I suggested conductance to be more appropriate although I could have omitted the more  Tease-smiley

It is not AC only, it does allow for the effect of reactive loads (capacitance and inductance) in DC circuits, but by all means use conductance if it makes you happy.

[Greg]

[VapingBad]

Anyway the point was don't spoil the ship for a ha'p'orth of tar by using these flat spring connectors that are for far lower currents, you go to all that effort making a mod just spend another hour and fix them or make something even better.

[domejunky]

I've just bought some 25Rs with nickel tabs from NKON. Putting them in a 1550p in parallel - with USB charging - kind of like a LiPo pack. I was shocked by the lack of sag when I wired them up on the bench...

Mooch also found a measurable difference in where on the battery clip he soldered his wires. So the clips must be introducing a fair bit of resistance.

[VapingBad]

We all knew it when we were using mechs, but seem to have forgot with the rise of high powered regulated mods and just trust what the shop stocks. In fairness to them I haven't seem a decent off the shelf cradle yet, though the Fat Daddy tube should be OK, if you happen to want a tube in your design.

[VapingBad]

We were talking about these and how bad FD 510s are at the vape meet last night and I remembered I had these photos of the Keystone not coping with a nearly 2 year old 25R. I doubt the current was extreme because the battery was not damaged apart from heat damage to the wrap from the temp the connector got to, probably over 600 C going by the colour chart here. The arching at the positive terminal that caused most of the damage is not the whole story as the negative has still got extremely hot from current that did not over stress an old 25R and shows these flat springs and especially the small contact patch can't handle the high current with today's mods. Flat springs belong in torches and not in over 10 W e-cigs IMO, but the good news it is a fairly easy fix with a couple of brass screws.

[igual]

Don't have any pics but I noticed this in a series mod I built, to correct this I ripped out the contacts and made some out of 0.8mm thick pure copper with a few turns of a stiff spring behind ( spring takes no current) .