Will my hack-job battery splice work?

[Pinesal]

I attempted to add another battery to my bike in parallel and the way I did it was to cut the wires leading from the battery to the controller and then I rejoined them with quick splice crimping connectors, except on one side of the connector an additional set of wires are connected that then lead to the second battery.

I am pretty sure this will work just fine but I want a second option before I connect the second battery.

 

[Drunkskunk]

Yeah, that's fine. All 3 ends of the red wire are electrically the same, All 3 ends of the black wire are the same. No worries.

 

[Tommm]

It is fine, if the batteries are exactly the same age, type, state of charge and so on.

 

[fechter]

I've done the same thing with no issues. Just make sure the batteries are within about 0.1v of each other before making the connection.

 

[John in CR]

I'd say it depends on the crimped splice connectors. Personally I would solder it, because otherwise moisture is going to get in there and start corroding the copper strands eventually leading to a poor connection. I your specific example I wouldn't have cut the original wire, just trim off some of the insulation and solder the new battery there.

Since you went the crimping route, I'd give it some moisture protection with heat shrink combined with liquid tape to fill in the gap where there are 2 wires.

 

[dogman dan]

You could have some issues with charging, if those batteries have a bms. If not, then no problem other than the connections need to be, and stay, solid.

For really good connections on my RC lipo packs, I like to use a thing called a crimp sleeve. They are intended for AC connections, and come in various sizes.