C Rating and JST discharge plugs?

[Coersum]

From what I read on forums (rcgroups and others).. jst plugs are good up to 10A (maybe a bit less but tested good up to 10A).

I see smaller mah batteries with jst plugs (which works with my esc), but as I was thinking about getting some 1000-1300mah 2S batteries, I see one with jst and the rest with XT60.

If I understand it correctly, the constant max draw of a battery is Capacity (in A) x C rating.. so say the 850mah 25C/40C Burst 2S nano tech I currently have would have a max substained load of 21.25A, so why does it have a jst discharge plug ?

Is it because having a jst plug would limit the "usage" of the battery since mostly only low Amp esc use jst plugs ? what about if someone puts a jst plug to match it on a 30A esc with a big motor ?

Or can jst/and smaller gauge wires take more than the 10A max I've read all around ? (I'm guessing not). Maybe I am totally wrong on the substained load of a battery vs load on the plugs/wires? I'm new and trying to learn as much as I can without making too many mistakes.

Basically trying to figure whenever to buy the 1000mah battery I linked above with the jst plug that matches my ESC jst plug, or buy a bigger ESC like the one from flitetest store that has an xt60 plug and buy a battery with XT60 plug on it. It's almost 20gr more than my current ESC (10A from headsuprc), as my setup doesn't pull more than 7A and is for power pack B type planes).

I would prefer to add 20gr of battery weight than 20gr of esc if I could hehe

 

[Hai-Lee]

From what I read on forums (rcgroups and others).. jst plugs are good up to 10A (maybe a bit less but tested good up to 10A).

I see smaller mah batteries with jst plugs (which works with my esc), but as I was thinking about getting some 1000-1300mah 2S batteries, I see one with jst and the rest with XT60.

If I understand it correctly, the constant max draw of a battery is Capacity (in A) x C rating.. so say the 850mah 25C/40C Burst 2S nano tech I currently have would have a max substained load of 21.25A, so why does it have a jst discharge plug ?

Is it because having a jst plug would limit the "usage" of the battery since mostly only low Amp esc use jst plugs ? what about if someone puts a jst plug to match it on a 30A esc with a big motor ?

Or can jst/and smaller gauge wires take more than the 10A max I've read all around ? (I'm guessing not). Maybe I am totally wrong on the substained load of a battery vs load on the plugs/wires? I'm new and trying to learn as much as I can without making too many mistakes.

Basically trying to figure whenever to buy the 1000mah battery I linked above with the jst plug that matches my ESC jst plug, or buy a bigger ESC like the one from flitetest store that has an xt60 plug and buy a battery with XT60 plug on it. It's almost 20gr more than my current ESC (10A from headsuprc), as my setup doesn't pull more than 7A and is for power pack B type planes).

I would prefer to add 20gr of battery weight than 20gr of esc if I could hehe

The whole current capacity of the connector or even the leads from the battery SHOULD be chosen by the lead/connector resistance as for the C number being the max current, well not exactly because the battery can always deliver far greater than its C rating though the C rating number is the maximum recommended repetitive discharge from the battery without serious permanent damage.

As for you wanting to use the JST already fitted and being confused by the range of alternate connectors Etc I found and use a simple solution.

About half of my current Hangar use JST connectors on 12A ESCs. The battery sizes range from 500mA through to 2200mA. Some batteries have JST connectors and others use XT60. I just use an adapter to allow me to use the XT60 batteries on my JST fitted ESCs.

You can either make your own or search around the internet for some retail adapters. I made my own!

Your query about drawing more current through the JST is best answered by stating the JST is relatively poor connector and can have a very small contact area and therefore relatively high resistance. If you try to draw more than your 10A or so current you could overheat the connector and it could melt, the insulation fail. the contacts migrate towards each other and touch. This is normally followed by a smoke trail, a total loss of control, a near vertical landing and a long time scraping burnt plane from the unburnt plane and making up new replacement plane parts.

For a simple rule make the ESC battery connector suit the ESC maximum current and buy/make battery adapter plugs/leads to suit the battery to ESC connection.

Just what works for me!

Have fun!

 

[ElectriSean]

Technically those JST-RCY plugs are only rated for 3A - http://www.jst-mfg.com/product/pdf/eng/eRCY.pdf

I personally only use them for video transmitters, and use XT30 and XT60 for battery discharge plugs.

 

[Coersum]

ElectriSean >

True, tested "ok" at 10A max from what I read but yes, I will keep an eye on wires and connectors just in case.

Hai-Lee>

That's what I thought but wanted to make sure, as long as you don't pull too much amps, JST is fine and lighter. But I think I might just get XT60 batteries so that I can use them for future higher amp setup and use an adapter when using it with my lower amp JST esc.

However I am no good at soldering so I think I'll get This one, unless someone knows of one on hobbyking (about to place a battery order).

Thnakyou guys.