sudomod

So these are probably a load of dumb questions, but im pretty new to this community and electronics so bare with me. I have a powerboost 1000c, Male to female JST connector from Adafruit, and a 4000 MaH battery from aliexpress(125054), and these Male JST with tail ends from amazon.

https://www.amazon.com/gp/product/B01DU ... UTF8&psc=1

as pointed out before and as seen in the picture attached, the polarity is reversed on the male JST with tail ends as the colors dont align with the adafruit JST. Is that what people mean by "check the polarity" of these male JST connectors with tail ends? Also, since the aliexpress is from china as well, would it be a good idea to make sure to check the polarity of the battery leads? like just make sure that the black lead is actually negatively polarized, and the red lead is actually positively polarized?

also, I don't think this really matters, but I dont need to check the polarization of the male JST connector with tail ends by itself(no batt attached), because the wires are technically resistors, and aren't polarized until they are connected to a polarized source(battery)?..

Lastly, if the battery lead's polarization are true to their colors, I would just solder the black lead to the red lead of the JST wire with tails since they are backwards? and vice verse for the other lead.

sorry its a lot, and also super noobish, I just want to be as confident and knowledgeable of the matter so I don't blow my battery up and set my house on fire lol. I did read the Battery Safety thread just trying to verify.

When it comes to battery it's always a good idea to use a multimeter to verify the polarity of the leads. It's a good practice to use red for the positive and black for the negative. But it doesn't really matter what color as long as you're connecting the leads to where they're supposed to be connected.