JST connector to 2s LiPo question

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tmorgenthaler

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Good evening all,
Mail came today, and I built my first altimeter, a Eggtimer Quantum. The build went really well, but I have a question about hooking up the battery. The LiPo battery I have has 2 different JST 3 pin connectors, one with two positive wires and a negative, and the other two negative and one positive. The JST connectors, although both 3 pin, seem to be slightly different as well. There is a third connection that I’m not sure what type of connector it is, and it only has two wires.

This is the one I got:


What is the purpose of the third wire on the JST connectors? Also, is there any issue using the JST connectors in HPR? Is the other 2 wire connector a better option?
 

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Titan II

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It takes three wires to balance charge a 2s lipo. Given you asked the question, I highly suggest you read up on them. The 2 wire goes to the alt (generally). JST are fine in HPR.
 

cerving

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You want to use the red connector, it's a "JST" connector (actually a JST-RCY). It's not hard to find the matching pigtail... virtually any hobby store will have it, or you can get them online.
 

epflyer

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I use the same battery in my high power rockets. One of the 3 conductor connections is the balance connector for charging. The other 3 conductor is for a brand of RC models. The 2 conductor connection would connect to the altimeter.
 

rharshberger

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You want to use the red connector, it's a "JST" connector (actually a JST-RCY). It's not hard to find the matching pigtail... virtually any hobby store will have it, or you can get them online.
just make sure if you buy them online that the red and black wires are not reversed when you recieve them or before use...it does happen.
 

Dane Ronnow

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JST-RCY connectors (male and female):

[Edit 2] I'm totally messing this up. Sorry. Here's a link to JST types. Scroll down to the table with the blue border. At the bottom of that is the JST-RCY. Just make sure the pitch is the same on yours. See post #10 below.


[Edit] I posted the following link before I looked closely at the Amazon listing for your LiPo battery. I think it's a JST-PH connector, not a JST-RCY.


JST-PH (male and female):


[/Edit]
 
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BenCook

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That smaller 3 pin connector is commonly used on smaller RC aircraft. I think that battery includes both the red connector and the smaller connector to be a universal fit.
 

tmorgenthaler

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You want to use the red connector, it's a "JST" connector (actually a JST-RCY). It's not hard to find the matching pigtail... virtually any hobby store will have it, or you can get them online.
Thanks Cris. That's what I assumed was the one I should use, but wasn't sure of the difference between them all. This is my first time using any sort of integrated electronics in rocketry, and I've never used LiPo batteries, other than what might be included in consumer electronics. I'd rather ask the question and look stupid, than do something stupid and destroy the electronics, or worse, the rocket.
 

tmorgenthaler

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JST-RCY connectors (male and female):

[Edit 2] I'm totally messing this up. Sorry. Here's a link to JST types. Scroll down to the table with the blue border. At the bottom of that is the JST-RCY. Just make sure the pitch is the same on yours. See post #10 below.


[Edit] I posted the following link before I looked closely at the Amazon listing for your LiPo battery. I think it's a JST-PH connector, not a JST-RCY.


JST-PH (male and female):


[/Edit]

Thanks for the link. I was looking for something like that last night and couldn't find a good one.

I actually had a box of JST connectors related to my 3D printer that I bought. Sadly, it did not include the RCY connectors, and the end of the plug I would need for the white connector is meant for to surface mount, not a pigtail. Even still, it only matched up to the larger of the two white connectors

@BenCook and @epflyer both mentioned the smaller one is used for R/C aircraft, so likely why it's not included in the box of JST connectors I have.
 

OverTheTop

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I actually had a box of JST connectors related to my 3D printer that I bought. Sadly, it did not include the RCY connectors, and the end of the plug I would need for the white connector is meant for to surface mount, not a pigtail. Even still, it only matched up to the larger of the two white connectors
If you have some JST-XH surface mount connectors you can use them if you need. They can be glued down with CA glue to a sled or other surface (keep the glue out of where the plug goes!), then wires soldered to the pigtails exiting the connector.
 
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