Which is the hot side?

[Nvreloader]

Hey Guys
My new air pump for the 48 and 52 V batteries just got here, it is this model,

Amazon.com

It has the goofy plug on it, so I made a couple of brass prongs that fit the plug and pressed them into the slots, I also split the Oem plug to fit the spacing for my Hailong 4 and 5 pin batteries.
All I need to do is figure out which side of the plug is the Hot and Neg sides.
I don't want to let the magic smoke out of my batteries while finding out.
I did notice that the OEM cord does have a ridge on one side and smooth on the other side.
I'll mark the hot side with red shrink tubing, to make sure.
Tia,

 

[dodgeman]

Do you have a volt meter? That will show.

 

[Nvreloader]

Hey Dodgeman,
Question for you,
How is a voltmeter going to show which is the Hot side and the Neg side? when there is NO power going to the plug prongs?
My volt meter does not say which side is hot or neg, that I KNOW of.
Thanks,

 

[Tars Tarkas]

DC motors typically run backwards if the polarity is reversed, so just try it. If it sucks instead of blows, just reverse the wires.

TT

 

[Slaphappygamer]

DC motors typically run backwards if the polarity is reversed, so just try it. If it sucks instead of blows, just reverse the wires.

TT

I thought that was only brushed DC motors. Pretty sure OP has a brushless motor.

 

[Nvreloader]

Guys
I guess I don't speak English, this is getting frustrating,

This tire pump DOES NOT have a battery or any type of power.

It has a standard type power cord that plugs into a BATTERY and the power cord is NOT MARKED for the Positive or Negative sides.

All I need to do, is figure out which side of the plug
is the Hot and Neg sides.

I don't want to let the magic smoke out of my batteries or hurt them, while attempting to find out which side is Pos or Neg.

Does anyone have this type of air pump.

Robot or human?

Tia,

 

[PCeBiker]

You're fine. Just plug it in and see if it works.
There's a diode inside the compressor, so it only runs if it's plugged in the right way.
It doesn't work and causes no harm if you plug it in backwards.

Electric Air Pumps 2024

,.. My advice is DO NOT DO IT. And they will never run out of gas. Those ebike-battery-powered pumps run $25 to $30. And since 2020 I've never had one fail. So... live and learn I guess :) . I decided to buy one,.. I've got this one too, but it's fricken huge and weighs a ton...

forums.electricbikereview.com

 

[Slaphappygamer]

Usually, the side with the ridges is the hot, but double checking like dodgeman said will dispel any mystery. Yet, without being able to supply a power source to the OEM cord there is no way to confirm our suspicions. If you check for resistance, you’ll just see whatever ohms value it is regardless of polarity.

That’s a very detailed post. Thanks @PCeBiker
Interesting that you mention the smooth wire and the ridged wire. That the ridge is always ground. I’ve found the opposite to regularly be true. The ridged wire is hot. Good to know that reversed polarity won’t damage the unit.

As a fun experiment, would you mind running the pump, then check if the ridged wire is hot?

 

[PCeBiker]

Interesting that you mention the smooth wire and the ridged wire. That the ridge is always ground. I’ve found the opposite to regularly be true. The ridged wire is hot. Good to know that reversed polarity won’t damage the unit.

As a fun experiment, would you mind running the pump, then check if the ridged wire is hot?

I plugged in the pump and checked the polarity.
It is written on both the battery and the plug.
I also checked it with my voltmeter.

The smooth wire is definitely the Positive or Hot wire.


I also checked my Polarized extension cord and the Line (or Hot) wire is also the smooth wire.

I also checked the AC voltage at the outlet, and got 120 VAC between Line (or Hot) and ground, and no voltage between Neutral and ground.

The Line wire is smooth and connects to the smaller bladed prong on a Polarized plug.

 

[Slaphappygamer]

The smooth wire is definitely the Positive or Hot wire.

Thanks for confirming that. One of us lives in oppositeland. Lol

 

[PCeBiker]

Thanks for confirming that. One of us lives in oppositeland. Lol

Check a polarized extension cord that you have and see what you've got.
I'm pretty sure that it's all the same in North America ?
Whenever I order plug-in stuff on-line, I order the US plug.

 

[Nvreloader]

PC
Thank you,
I thought, I had seen something on this info here,
I looked, but did not go back far enough to find your post.

I just checked and tested the pump and it did work,
now the Pos side is marked with a Red heat shrink tube on that side.

The smooth side was the positive side.

The pump is outstanding and moves lots of air.
I now have one for each bike that will stay on the bike,
no more swapping back and forth or forgetting it on the rides.
Tia,

 

[Nvreloader]

Here is a couple of photo's on how I converted the OEM plug to a standard type US plug to fit my Hailong bike battery's, and the OEM plug fits inside the pump case.

 

[Slaphappygamer]

Looks great!

 

[PCeBiker]

Yeah,. your plug looks ""OEM"

Mine looks homemade.