The first problem with the battery and motor hub

[Smurf2]

Hi. It seems that I have my first real problem with the battery. But I hope that is just connectors...

The battery is stuck and won't go out, even if unlocked!

How it started: One day I charged the battery to about 90% and went to work. After I was returning, the battery on throttle started acting strangely. A voltmeter started fast-changing values, like when I set the throttle, it jumping like 60% to 40% to 20% to 0% (not exactly) and then went up and down continuously. Then stay for a while at 0%. Throttle not working! Then again working normally for a few minutes.
I come home in third PAS gear, easy, somehow it works like that.

I recharged it fully and tomorrow again went to work. It worked normally for about 7 km (how is that possible?), then again started happening. It shows 0%. No throttle. I removed the easy battery on the road to see if it was seating good in connectors, I didn't see anything strange. Return the battery back and I came to work in PAS 3.

There, I had a time to better check connectors, but guess what, battery won't come out anymore!

Is it "stuck" somehow connected to battery failure, like maybe connectors are melted? I hope not.
I think that is just a stuck screw that goes from the battery holder to the bike frame (I found a picture of how it looks inside). Maybe the connector jack moved, or maybe something else.

Ok. First, let's pull the battery out somehow. Don't tell me about the battery lock cylinder (if you call it that), cylinder works fine and locks/unlocks without a problem.

My idea is to remove the 4 zip ties to remove the battery with holder together from frame, and then try to remove it from the inside of the bracket. But then I don't have an idea of how it would go out, because of that screw in the frame.

 

[99t4]

Try placing a block of wood on the back end of the battery and tapping the wood lightly with a heavy hammer to try to pop the battery out of the base.

 

[offGridDownUnder]

tapping the wood lightly with a heavy hammer

As the surrounding bits (frame, battery) are expensive, I'll second this. I'll further encourage putting the bike in it's side, upside down, right side up, front down, etc. while trying this.

Tough situation, Just wanting to offer encouragement.

 

[Smurf2]

I somehow managed to get it off. I put the bike upside down, pushed up the battery with a hard wiggle, then it jumped out. Didn't figure out what caused it. Plastic melts and stuck?

Now guys, what caused a burned connector?

I see that connectors are easy fix, but need long waiting thevorder and choose right one!

Strange sound
My ebike always has some strange sound under first motor strain, and I call it normal.
It happens when the bike is stationary, and you hit a hand throttle. It sounds like its "suffer". To help a motor, I always release the throttle and throttle it again, then sounds return to normal.
But, that sound, last 2 days, when new this problem first appeared, it seems that become louder to me.
So, can it be burnout from the controller? I didn't open his case yet.

Also, after last cleaning of the battery leads (maybe a year ago), it was easy to slide in/out without too much friction (so easy that if you did not lock it, it might jump out). So, maybe burnout happened because pins of connectors were not touched enough or the battery jumped on vibrations in/out in millimeters, and sparks happened often? (When the battery is locked it still can be slide in/out by a few mm).

May I open the battery to reach the connector and see the dimensions for ordering?

 

[Matt Gruber]

I make my own connectors with a piece of scrap copper pipe, or you could buy a 1/2" elbow for less than $1. cut it and shape it. good luck!

 

[OlderGiantFan]

That bottom connector in the third pic, I had a few of them on some radio antenna gear I left exposed to the elements and in 4 weeks that gold coating was pushed off by rust. Underneath was this cheap metal. The Chinese are making some real crap and it's finding its way into all manner of gear. Just be aware of that, and the fact that steel/tinplate doesn't conduct current nearly as well as solid copper. Copper is up to 8x better and some cheap connectors can actually act like resistors and heat up.

Table of Electrical Conductivity

https://www.thoughtco.com/table-of-electrical-resistivity-conductivity-608499

Lead's electrical conductivity is about 7% that of copper but it's used for battery terminals because it is malleable, cheap, and resists acid corrosion. Greater surface area is the key to performance with battery terminals on cars etc and contact surface area matters in all high current applications.

 

[Smurf2]

Smurf2 says:

• Now guys, what caused a burned connector?
• May I open the battery to reach the connector and see the dimensions for ordering?

 

[99t4]

(When the battery is locked it still can be slide in/out by a few mm).

This is almost certainly a large part of your damaged connector problem.and will continue to quickly degrade any new replacement connector you install.

Solve the loose battery problem by tightly strapping it to the base so it can't move.

OVERALL: This problem was caused by

• poor design-- weak hold down mechanism
• poor quality control
• insufficient testing
• Cheap materials

Not really your fault, except for buying low quality equipment.

 

[Smurf2]

Ok.
@99t4 Why you think that every next installed connector wont work? Because of bad and cheap material or?

And do you mean is it that voltage drop just a connector problem, or is it battery damaged?

With multimeter measurements from outside of battery we can't tell if it's still good, or? Because voltage drop will be shown on battery sag, I think.

 

[OlderGiantFan]

With multimeter measurements from outside of battery we can't tell if it's still good, or? Because voltage drop will be shown on battery sag, I think.

Multimeters tests of this sort are like mirrors on vehicles, they say No, but they don't say Yes. What that means is that it might show a good connection, but for all you know the connection could be just a couple of strands thick. The low current draw of a MM won't tell you the condition of the cables or connections, only direct visual inspection will, like turning your head to look over you shoulder to see if a car is coming.

 

[Smurf2]

Ok.
I am surprised that the seller didn't lie that there are real Samsung 3500 mAh batteries inside!

I am surprised that all batteries are in a plastic holder case! Nice.

I am surprised that the blue cover tape is cut for some reason. Is it normal that blue cover tape is cut? (I am the first customer).

Guys, I am scared of doing that, and need your support. The glue around the connector is strong and will be hard to remove.

It can't explode if I'm just trying to remove the connector and holding the positive and negative wires separated, right? Some other safety suggestions maybe?

 

[99t4]

@99t4 Why you think that every next installed connector wont work? Because of bad and cheap material or?

I didn't say it won't work, I said it would fail again, based on what you described:

So, maybe burnout happened because pins of connectors were not touched enough or the battery jumped on vibrations in/out in millimeters, and sparks happened often? (When the battery is locked it still can be slide in/out by a few mm).

So even with a new connector, the loose battery will continue to unseat/seat the electrical contacts, pitting and eroding them until failure.

It can't explode if I just trying to remove connector out and holding positive and negative wire separated, right? Some other safety suggestions maybe?

Keep the + and - wires separated, don't handle both at the same time. Especially not one in each hand (creates a pathway through the heart). Don't disturb any other wires. Take your time. Favor safety.

 

[Smurf2]

So even with a new connector, the loose battery will continue to unseat/seat the electrical contacts, pitting and eroding them until failure.

Yes, don't worry, I will figure out something about that, when I reach that point.

Tnx.

 

[Smurf2]

Unsoldering that connector was really pain in the a.s. It was very hard to remove it because solder won't melt it mixed with plastic and hot glue. Then I set solder iron to 400 C° and that works.

The connector number is pla077010. Not too many options for ordering from the EU. I was ordered from AliExpress, now waiting maybe month or more, because a small package

View attachment 388207

 

[Matt Gruber]

looks similar to the 3/8 copper pipe on my old kitchen faucet. so I don't see what is the problem? just go over to Home Depot and grab something similar size and fix it.
Or you buy a new battery. then you can attempt to fix it as a spare or keep for the spare cells.

 

[Smurf2]

Guys, connector has come; let's get back to business!I love when orders from AliExpress come extremly fast-one week!

The connectors look pretty identical. The joint is very tight.

I hope that I will not mess them up with the soldering iron and melt plastic.

As you can see, the red wire cover is peeled off about 1cm. But I will not cut them because the wires are too short (it affects opening the battery box). So, I will put some heat shrink, maybe a few levels.

 

[99t4]

I hope that I will not mess them up with the soldering iron and melt plastic.

That's going to be tricky. Do you have experience soldering larger wires? Requires a larger more massive tip and higher wattage. For quick in and out, done operation. Otherwise spend too much time with a wimpy tip and end up melting the plastic housing and wire insulation.

What's the access like on the wire connection side of the connectors?

 

[Matt Gruber]

often the connector is removed to solder or crimp.

 

[Smurf2]

Do you have experience soldering larger wires?

What's the access like on the wire connection side of the connectors?

I've done a few XT30/XT60 connectors before on my e-skate, e-bike and drone. I have a soldering iron of 450°C. I will set it to max.
These are my tips:

I melt the plastic, as you can see when I pull the connector out, because I set it only around 300 °C. When I increased temp., it went easy out.

On the battery connector, will be a little tricky and challenging. You see that access to the pins for soldering is a little "in the hole". So, some plastic behind that pin might be a melt, but who cares?

On the bike frame, male connector, do I change it or not? (I can scrape out/grind that bad pin). But maybe better both? This connector needs to be a little modified. You see that on the old connector I removed a little part so that connector can lie down nicely over the screw head.

 

[offGridDownUnder]

I hope that I will not mess them up with the soldering iron and melt plastic

I tried this and melted the plastic. My iron could not deliver heat rapidly enough to raise the temperature of the metal to flow solder before transmitting on enough heat to also melt the plastic.

My fabricator had a more powerful machine with settable temperature that could, and he soldered the connection for me starting with a fresh terminal.

Now, I keep a spare that was soldered at the factory.

 

[99t4]

That is my preference also, to buy connectors with pigtails. Make life easy.

 

[Smurf2]

It is late for pigtail. I already bought connectors

Which glue was on the connector and wire which I barely took off (post #11, #14)? Is that super glue or hot glue?

I have some cheap hot glue, but I suspect that will hold tight.


Also, I have super glue and epoxy.

 

[Smurf2]

How did they predict that this screw must go in?
There is no thread. I think it will be broken with force.

As you see on the old one, the screw is fully tightened, but it broke the plastic (That came from the factory. Not by me).

If I heat the screw and screw it, would that work?

 

[offGridDownUnder]

There is no thread

Self-tapping screws. It can be done right and work. It's not usually used when disassembly is expected.

 

[Smurf2]

Connector is done.

Strange sounds still persist!

Listen to the video I recorded. Who knows what that sound is? Controller or motor?

Sound:

I am afraid to drive fast, to not burn the connector, again.