Soldering cradle terminals to controller

[Ethanator10000]

This is probably a stupid question, but I can't find any specific instructions and am curious as to how others do it:

What's the best practice for soldering my grin baserunner to the terminals in my downtube battery cradle? There are 4 pins (2 +ve, 2 -ve) and of course two wires. Should each wire just be soldered to one pin each? Or should each wire be connected to both of the respective positive and negative pins? If it's the latter, what's the best technique for that?

 

[amberwolf]

How is the battery itself wired inside? Does it use both sets of terminals, or only one? If only one, then you either have to use the mating set, or both sets. If it uses both sets, you could use either or both, depending on the amount of current expected to be required.

If the cradle terminals are pairs of same polarity next to each other, (as opposed to alternating polarities) and have holes in them that your wire will fit thru, I'd just bend the end of each one in an L, with that bottom angle of the L being long enough to almost touch the third terminal, and place the bottom angle of the L into a pair of terminals, bend that excess back toward the second terminal's face, and solder it there on both terminals. You'd want to make sure enough insulation is removed so that some of the main L "vertical" part's conductor is soldered to the face of the first terminal. (the idea is to have as much conductor actually up against the terminal as possible, so the solder doesn't have to do that job (just hold the stuff in place).

 

[Ethanator10000]

How is the battery itself wired inside? Does it use both sets of terminals, or only one? If only one, then you either have to use the mating set, or both sets. If it uses both sets, you could use either or both, depending on the amount of current expected to be required.

If the cradle terminals are pairs of same polarity next to each other, (as opposed to alternating polarities) and have holes in them that your wire will fit thru, I'd just bend the end of each one in an L, with that bottom angle of the L being long enough to almost touch the third terminal, and place the bottom angle of the L into a pair of terminals, bend that excess back toward the second terminal's face, and solder it there on both terminals. You'd want to make sure enough insulation is removed so that some of the main L "vertical" part's conductor is soldered to the face of the first terminal. (the idea is to have as much conductor actually up against the terminal as possible, so the solder doesn't have to do that job (just hold the stuff in place).

Beautiful, thank you. I'll do the "L".

 

[offGridDownUnder]

What's the best practice for soldering my grin baserunner to the terminals in my downtube battery cradle?

My battery case has polarity symbols molded into the plastic by the 4 spade slots, and that shows mine is 2x + besides 2x -

For me, the two outer spades are connected each to the black or red wire to match.

You may be knowledgeable, but beware the soldering kit you use for this. A home soldering iron delivered heat too slowly for me and the plastic began melting before the metal became hot enough to melt the solder. I had to take it to an e-bike shop who had an iron that delivered enough heat at a high enough temperature to melt the solder before the heat made it to the plastic in any great quantity.

Others here may be able to shed light (heat) on this.

 

[Ethanator10000]

How is the battery itself wired inside? Does it use both sets of terminals, or only one? If only one, then you either have to use the mating set, or both sets. If it uses both sets, you could use either or both, depending on the amount of current expected to be required.

If the cradle terminals are pairs of same polarity next to each other, (as opposed to alternating polarities) and have holes in them that your wire will fit thru, I'd just bend the end of each one in an L, with that bottom angle of the L being long enough to almost touch the third terminal, and place the bottom angle of the L into a pair of terminals, bend that excess back toward the second terminal's face, and solder it there on both terminals. You'd want to make sure enough insulation is removed so that some of the main L "vertical" part's conductor is soldered to the face of the first terminal. (the idea is to have as much conductor actually up against the terminal as possible, so the solder doesn't have to do that job (just hold the stuff in place).

Well I tried it.. and I'm not sure I trust my work and I'm a bit stressed out if I ruined my baserunner

I tried soldering on before I got your comment last night and the wires ended up blocking the baserunner from being installed in the cradle and I had to desolder the terminals and cut the wires.



My soldering iron is a bit wimpy as @offGridDownUnder said and doing the "L" took me a few tries as I had to restart after doing one side since there wouldn't be enough slack in the wire left to thread the other one. Unforuntately now there is barely any wire left on the baserunner as I had to cut and restart a few times, so I took some 12awg wire I had from my RC days (and it's super flexible so that helps here) and soldered the L's on first and then tried splicing that onto the baserunner so that I could have some more cable to work with. This came out a bit rough looking with my wimpy soldering iron, and the heatshrink I slid over shrunk from the soldering heat and I couldn't slide it over the splice, so I just wrapped it in electrical tape for now.



At this point I really don't know what to do.. is using 12awg wire here okay? I'm not sure what guage the baserunner wire is, but this 12awg felt a bit thicker than what was on it. I'm worried that I won't be able to do anything else on the positive wire because of how little is left on the baserunner. I have access to a much better soldering station at university so I can try redoing it there, but whatever I do I think I will have to start with carefully soldering on a positive wire extension. I'm not sure if the baserunner can be opened up and have that wire replaced.