Hello guys:
There is a lot of confusion and wrong sources online between wires gauges and it’s maximum withstand current, there are a lot of different type of wires, different insulations and materials, at the end some online charts could be misleading.
In this hobby we use silicone flexible wires so this table is the one we should use:
how is “withstand current” defined?
I mean, doesn’t the current a given cable can withstand depend on the distance it has to travel?
how does this compare with my current resource?
Conductor Current Ratings [SRO]
As I understand the withstand current (thermal withstand) is the maximum current at which a given wire starts to generate heat and deteriorate the cable insulation causing a failure.
at what length? resistance plays a function…
?source?
just curious…
Exactly what @kook said. Length is incredibly important here. Some ratings are likely done at 1 meter and some are done at 100, but that’s important to identify.
A 16g wire will not handle the same amount of current at the same temperature at 16 inches vs 1 inch. I’d love to see some data on this specifically. Im sure there’s a balance with resistance as well
even the chart linked by @eboosted that has the chart @b264 posted, none of those amp ratings specificy the length of the connections for the nickel strip. All things im curious about.
@eboosted has shown before where small 14g(?) wires were used as series connections in a high amp pack. All because the series connections are short where as the longer battery cables are much thicker. Theres little data captured about this. Would love to see someone like Mooch who does a lot of the 18650 and 21700 cell testing online provide data about this – he likely has the equipment.
When the limiting factor is resistance generated heat breaking down the insulation the length doesn’t matter. The current loss increases as the wire length increases but the important factor here is current loss per unit length. That turns into heat generated per unit length and a corresponding temperature increase in the conductor that damages the insulation.
If the limiting factor is total current loss then the length is important.
exactly
I like the detail @eBoosted’s table and since the values are somewhat higher than the the values given in Brian’s table, I’m guessing that these are ratings for a shorter run of wire.
In other hobbies, tables wire table selection charts exist that match length and current load. I would love something like this for the scale we are working with. In the meantime, I like how @b264’s chart is laid out
