Newbie here, how do I connect my battery to my controller?

[waratte]

Hi, I just bought a generic kit from amazon (link) for my bike and the only thing I'm lost on is how to connect the battery to the controller.

The wires in question on the controller look like this:

The plug in question on the battery looks like this:

Any ideas?

 

[Sunder]

First idea...

Don't post photos that have their permissions set to private (I get a permission denied trying to view your images at least).

So what's the actual problem? The plugs are different?

 

[waratte]

First idea...

Don't post photos that have their permissions set to private (I get a permission denied trying to view your images at least).

So what's the actual problem? The plugs are different?

Alright, I fixed it, should display now from imgur.

But yes, the plugs are indeed different and I'm not sure how to go about this.

 

[Sunder]

Thanks. Much better.

The top photo (Controller) looks like 4mm bullets, and the bottom photo looks like a standard jug cord.

You have the choice of either staying with bullets or jug cord. Personally, I would stay with the jug cord (Easier to connect, especially inside a bag, and sparks are partially shielded by the plug), but I know I'm going to get shouted down here. (Higher resistance, 4mm bullets are very common).

You can go to any computer store and ask for a standard 3 prong power cable or jug cord. Once you have that:

1. Cut the cable and keep the half that plugs into your battery
2. Strip the insulation and cut off the earth (usually green and yellow)
3. Cut off the bullets.
4. Figure out which prong is positive, and which is negative on the controller and match to the battery. Check, double check, use multimeter, do not get this stage wrong, or you're up for a new controller.
5. Solder, then insulate (electrical tape, heat shrink etc).

If all went well, you should be able to power up your controller.

 

[Sunder]

Oh, third option, which is what I would personally choose, is swap to XT90s or Andersons.

Andersons are probably the most popular ones here. They are hard wearing, easy to assemble, and once you pin the positive and negative together right once, you can't accidentally reverse polarity. However, I find them hard to assemble in the dark/inside a bag.

XT90s are my personal favourite. Carry huge currents. very easy to solder/assemble, spark is totally hidden, can't reverse polarity, very easy to line up even in the dark/inside a bag:

 

[waratte]

Ah, I see, darn.

Would it be a good idea to get an adapter for my bullet plugs? I'm thinking of getting this: link.

Then replace the battery's jug plug with this (since it looks the easiest to replace): link

Would this work?

 

[Sunder]

Getting the adapter would work and save you having to cut the old bullets off, but personally, I like the fewest connections. Least losses, least places to corrode, least things to go wrong.

If you're not confident soldering, then your strategy sounds best.

If you have the option of turning off the battery before changing the jug cord, definitely do it. I don't have any handy photos, but these eBike batteries are pretty unforgiving if you short them. Very first pack I did (wow... 5 years ago now?), I was foolish enough to cut both wires off at the same time to change the plugs. One moment of inattention, they touched, and molten copper burned a hole in my carpet. Was damn lucky it wasn't my eyes.

Edit: Here's someone else's photo of a LiPo short:

 

[waratte]

Alright, I'll try it, and thanks for the heads up.

This is a pretty big lithium battery (nearly as heavy as the bike's motor w/ wheel), I'm sure it won't be pretty if something like that happens to it.

 

[spinningmagnets]

A "pigtail" is a common term for a connector that already has a few inches of wire soldered to it. I highly recommend buying pigtails, and just solder the butt ends of the wire together after you cut off the old connectors. As stated above, the Andersons and XT90's are the most popular right now. Both are good, if you want Andersons, buy a red/black "extender" set, and cut the two wires in the middle.

http://lunacycle.com/connectors/xt90-connectors-with-pigtails/

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http://www.powerwerx.com/adapter-cables/powerpole-bare-end-adapter.html

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The Amberwolf method of soldering butt ends of wire.

 

[rider95]

Just call up or send a quick e mail to the ppl you bought it from and ask them after all theay sold it too you