Which electrical connectors to use

Emeraldtarpon · Sunday at 1:35 AM

Hi all,
It's my first build and I've gone and ordered the wrong motor so my system is a bit of a mis-match:-
2860, 2190kv motor.
I had to up the ESC to 150A to cope with motor (apparently I'm looking at 133A).
5200 100c 3s lipo (apparently 3s is my safest option under the circumstances).

Now, connectors
The battery's got an XT90 plug, all good BUT the motor has 3.5mm bullets attached...I would have thought a 2860, 2190kv motor would have larger connectors??...4.5mm atleast?
Do I need to change the motor connectors to 4.5 - 5mm bullets and use XT90's??
The other thing is the thickness of the motor wires, approx' 2.6 to 2.7mm dia (not sure the correct terminology)...again, I would have thought the wires would have been heavier/larger dia on this motor?
Should I use XT90's for the above set-up? as I'm sure xt60's wouldn't cope, is this correct?
Thank you for your help, cheers

Paul Traufler · Sunday at 9:22 AM

The XT90 is rated for 90-120A continuous so you are ok with that part, the 3.5mm are rated for ~50A, now remember you have 3 wires carrying the load to the motor so you are looking ~45A max per leg. The battery only has 2 wires to carry the load so they see the full current.

Now I will also say not all connectors are created the same and stick with name brands and you will be fine. The fit MUST be tight for the connectors or they will overheat and un-solder themselves.

Paul

Emeraldtarpon · Sunday at 6:14 PM

Paul Traufler said:
The XT90 is rated for 90-120A continuous so you are ok with that part, the 3.5mm are rated for ~50A, now remember you have 3 wires carrying the load to the motor so you are looking ~45A max per leg. The battery only has 2 wires to carry the load so they see the full current.

Now I will also say not all connectors are created the same and stick with name brands and you will be fine. The fit MUST be tight for the connectors or they will overheat and un-solder themselves.

Paul

Thank you for your reply Paul, I appreciate it.
I'm still wrapping my head around this stuff so every bit of info I get is giving me a better understanding of what I'm actually doing and whether, what I'm trying to achieve, is possible or within acceptable limits.

The battery already has an xt90 so if I was to use xt90 on the ESC and change the 3.5mm bullets on the motor to 4.5-5mm, i should be OK?
Will the 3s cope fine? (was suggested i go with 3s due to me getting wrong motor...safest option under the circumstances).
Many thanks

Emeraldtarpon · Sunday at 9:13 PM

OK, just had a read and it looks like 6mm connectors would be a lot safer than using xt90's...sounds like the xt's would be in danger of over-heating/melting with the 150A ESC.
Can I just use 6mm bullet connectors (handle up to 180A) for everything...motor, esc, battery??

Paul Traufler · 2024-11-11T06:19:01-0500

Emeraldtarpon said:
OK, just had a read and it looks like 6mm connectors would be a lot safer than using xt90's...sounds like the xt's would be in danger of over-heating/melting with the 150A ESC.
Can I just use 6mm bullet connectors (handle up to 180A) for everything...motor, esc, battery??

You can go with the 6mm for the battery, that is fine, however the motor part that is WAY overkill. The 3.5mm are fine, remember that the motor legs are way lower current then the battery and this is not a constant current thing but rather a pulsed power on the motor legs.

Most of the high power side go with 8mm for the battery that will cover pretty much any power you would need. One thing to remember is the bigger connectors are harder to solder also so that can be an issue. A GOOD SOLID connection is needed or there will be trouble.

Keep asking questions as the road to understanding has many paths...

Paul

Emeraldtarpon · 2024-11-12T05:57:00-0500

Paul Traufler said:
You can go with the 6mm for the battery, that is fine, however the motor part that is WAY overkill. The 3.5mm are fine, remember that the motor legs are way lower current then the battery and this is not a constant current thing but rather a pulsed power on the motor legs.

Most of the high power side go with 8mm for the battery that will cover pretty much any power you would need. One thing to remember is the bigger connectors are harder to solder also so that can be an issue. A GOOD SOLID connection is needed or there will be trouble.

Keep asking questions as the road to understanding has many paths...

Paul

Thank you Paul,
OK, I understand now, a bit of knowledge goes a long way...cheers.
Ive got 6mm connectors but I'd rather err on the side of safety so 8mm it is.
Will leave the 3.5mm on the motor and just attach the female connectors that came with the motor, to the esc.
I assume I attach 8mm to the power wires on the esc (as well as the battery).
I believe I'll be good with a 3s 100C lipo, due to its higher discharge rate, correct?
I'm using a 3s lipo as I mistakenly purchased a 4 pole motor, as stated previously.
Thanks for your patience Paul, I really appreciate it (I'm definitely getting there bit by bit : )