Hub motor melting 3 phase wire connector to controller

[easyrider15]

Hi everyone,
I need a little help with a recurring problem l have.
l resently bought a standard Chinese "Champion" 48v 1000w rear hub motor kit from ebay.
l also bought (from a different seller) a, what he claimed was a 48v 20ah Lifepo4 battery and charger for £330. When the battery arrived it had a sticker saying 48v 10ah, when a approached the seller he said the sticker was "to get the battery through UK customs cheaper"????? what a crock. It's covered with 1 year warrenty and covered by ebay so l thought i'd give it a try. It seems rather small for 20ah.
Anyway I assembled the kit onto a downhill bike and on my first test run l did around 15 miles at about 15-20mph unassisted. (l'm actually more Wheasyrider than Easyrider) . When l was checking the wiring l noticed that the 3 bullet connectors on the 3 phase wires had melted and fused together. I did a temporary fix and rewired using a large choc block connecter but the same thing has happened again melting and deforming the plastic sheath.
l am thinking of buying a new kt-lcd3 controller with the programable lcd unit which l can restrict and should make me road legal, but l would like to solve my melting connector problem before l fit a new controller.
Does anyone know where l can buy a kt-lcd3 controllor in the UK, Germany is the closest l could find other than China
attachment=0]IMAG0077 (640x383).jpg[/attachment]

 

[100volts+]

Wow. How many amps are you running? I run 125v at 150 battery amps (220 phase amps) and it doesn't do that. PS I don't like bullet connectors on the phase connection. I use butt connectors.

 

[wesnewell]

Get some gold plated 4mm billet connectors. They rated for 90A. You're probably pulling a max of 30A. Loose connectors is what usually causes the connectors to over heat. for ference;
http://www.ebay.com/itm/10-Pairs-4-0mm-4mm-Gold-plated-Bullet-Connector-Banana-Plug-RC-Battery-/381037556885

 

[wesnewell]

Get some gold plated 4mm billet connectors. They rated for 90A. You're probably pulling a max of 30A. Loose connectors is what usually causes the connectors to over heat. for reference;
http://www.ebay.com/itm/10-Pairs-4-0mm-4mm-Gold-plated-Bullet-Connector-Banana-Plug-RC-Battery-/381037556885

 

[d8veh]

The best controller IMHO is the S12S from BMSBattery. You'll need the external speed sensor, S-LCD3 and a decent PAS to go with it. If your motor is sensorless, it has to be the S12P controller. Don't worry about buying them from China.



It's not uncommon for the motor connections to get hot. The better quality controllers have silicone rubber shrouds over them so they don't melt. You can either upgrade to decent bullet connectors or cut the connectors off and solder them directly together.

 

[easyrider15]

Thanks everyone for your help with my overheating.
According to the spec that came with the battery - Rated Discharging Amperage: 20 Amps Max Continuous Discharging Amperage: 30 Amps.
l'm new to the ebike scene and this is my first kit so l'm still learning, so as far as sensors go l'm not sure. This is the item number of the kit l bought on ebay, he is still selling them - 151495184427 it says it has a pedal assist sensor.
The kit came originally with bullet connectors but they melted together that's why l fitted the block as a temporary fix.
I read in the forum about "hotroding a hub motor by thickening up the wires from the hub to the controller. One fix suggested drilling out the centre of the hub axle a bit and another fix which saved doing this, was cutting the wires just after they come out of the hub axle.
What would be the best way to join up the wires and will this stop the melting connector problem??
Can someone please let me know if they think l've done any serious damage that can't be fixed, l don't want to buy a new kt-lcd3 controller £75+postage from Germany if l'm just going to burn it up
Thanks everyone
I'm off to get some 12 gauge wire and bullet connectors

 

[easyrider15]

Could someone please tell me what's causing this to happen? l'm worried in case l've done any terminal damage.

 

[999zip999]

Wesnewell did answer your question. Loose connectors, junk connectors. Get the 4mm connectors, keep your wires short. The small hall can be left long so no need to rewire.

 

[Doctorbass]

Oh wow.. there is so much heat that appear to have been lost on these poor connector than I'm sure that once you will have solved that you will FEEL the torque difference ! :lol:

 

[easyrider15]

Thanks again everyone, I will change the connectors at the weekend
Phwew!, l thought i'd done some serious damage there.

 

[friendly1uk]

I don't think it was loose. It's too uniform. More like when someone does all the connections equally too tight. Flattening the cable to nothing. Reducing it's current carrying capacity by a large proportion.

Tip: Double your contact area

 

[mybike]

I have got the very same motor I had no problems with it. I don’t use the controller that came with it. Very smooth ride even at 10mph although i was told I brought the wrong motor. It even has no problems getting up hills. I never installed all the kit that came with motor I just installed the motor from the kit.
Make sure you put the motor on right as when I got mine the washers were in the wrong order.

Change your controller that came with it and if you buy a controller that’s rated 30amps or under use the 30Amp connector blocks if you want to keep connector blocks (i have).

I also have in line 30Amp fuses in the negative and positive battery side.

I running the motor hall less and its runs fantastic!

 

[easyrider15]

Thanks guys,
I'm trying to get a new controller "mybike", I've been trying to get a KT-lcd3 with 48v 1000w controller so I can restrict the motor for road use, but Germany or China are the only places I can find them, does anyone know where I can buy one in the UK. I too am impressed with the kit and apart from this problem everything has been fine. I'm 78K and it pulls me up hills without pedaling no problem i've had 20, 25 and about 30mph from the 3 speeds. Great fun. I like the torque and the acceleration is as good as a small car and easily better than trucks.

That's very interesting friendly1uk, that's exactly what I did, I tightened the block screws as tight as I could, I've always thought that's what you did. It would have definately crushed the wires flat. I've just refitted new 4mm bullet connnecters recommended by Wesnewell and I've thickened up the wire from the hub to the controller to 10 gauge, it's now the same as the short wires that come from the controller.
When I fitted the new bullet connecters I crushed the connecter as tight as I could onto the wire, would that be ok??

 

[wesnewell]

I hope I'm misunderstanding your post and you didn't crimp the bullet connectors onto the wire. They have to be soldered on.

 

[easyrider15]

Ahh Thanks for that wesnewell, yes I did crimp the bullets but I'm off to buy some solder now.