Cutting phase wires?

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ebike11   1 MW

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Cutting phase wires?

Post by ebike11 » Jan 22 2022 9:21am

Hi all!
Is it worth/beneficial to, for example, cut the phase wires on a qs273 motor, leaving about 15cm sticking out of the motor then replacing the rest of the long phase wires that were cut with 6awg wire on each phase and crimping everything tight??
Its almost impossible to fit thicker wire through the axle so this seems like the only option at the moment.
Or would the gains be minimal or not worth the effort?
Ill be running over 100V and pretty high amps when in bursts.
Thanks!

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Re: Cutting phase wires?

Post by E-HP » Jan 22 2022 9:46am

ebike11 wrote:
Jan 22 2022 9:21am
Hi all!
Is it worth/beneficial to, for example, cut the phase wires on a qs273 motor, leaving about 15cm sticking out of the motor then replacing the rest of the long phase wires that were cut with 6awg wire on each phase and crimping everything tight??
Its almost impossible to fit thicker wire through the axle so this seems like the only option at the moment.
Or would the gains be minimal or not worth the effort?
Ill be running over 100V and pretty high amps when in bursts.
Thanks!
I'll probably do that, but mainly when adding connectors near the motor for easier maintenance. I think I'll do some tests with a spare thermistor and CA and see how much hotter they get under high current first, then decide whether to upgrade the wires or just use the stock ones when adding the connectors. By feel, I haven't noticed anything, but they probably cool down quickly, so a probe would give better data. They also sell probes with displays for $10 on Amazon, but I already have a spare thermistor.

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Re: Cutting phase wires?

Post by ebike11 » Jan 22 2022 10:27am

E-HP wrote:
Jan 22 2022 9:46am
ebike11 wrote:
Jan 22 2022 9:21am
Hi all!
Is it worth/beneficial to, for example, cut the phase wires on a qs273 motor, leaving about 15cm sticking out of the motor then replacing the rest of the long phase wires that were cut with 6awg wire on each phase and crimping everything tight??
Its almost impossible to fit thicker wire through the axle so this seems like the only option at the moment.
Or would the gains be minimal or not worth the effort?
Ill be running over 100V and pretty high amps when in bursts.
Thanks!
I'll probably do that, but mainly when adding connectors near the motor for easier maintenance. I think I'll do some tests with a spare thermistor and CA and see how much hotter they get under high current first, then decide whether to upgrade the wires or just use the stock ones when adding the connectors. By feel, I haven't noticed anything, but they probably cool down quickly, so a probe would give better data. They also sell probes with displays for $10 on Amazon, but I already have a spare thermistor.
What type of connectors will you plan on using?

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Re: Cutting phase wires?

Post by E-HP » Jan 22 2022 10:31am

ebike11 wrote:
Jan 22 2022 10:27am
E-HP wrote:
Jan 22 2022 9:46am
ebike11 wrote:
Jan 22 2022 9:21am
Hi all!
Is it worth/beneficial to, for example, cut the phase wires on a qs273 motor, leaving about 15cm sticking out of the motor then replacing the rest of the long phase wires that were cut with 6awg wire on each phase and crimping everything tight??
Its almost impossible to fit thicker wire through the axle so this seems like the only option at the moment.
Or would the gains be minimal or not worth the effort?
Ill be running over 100V and pretty high amps when in bursts.
Thanks!
I'll probably do that, but mainly when adding connectors near the motor for easier maintenance. I think I'll do some tests with a spare thermistor and CA and see how much hotter they get under high current first, then decide whether to upgrade the wires or just use the stock ones when adding the connectors. By feel, I haven't noticed anything, but they probably cool down quickly, so a probe would give better data. They also sell probes with displays for $10 on Amazon, but I already have a spare thermistor.
What type of connectors will you plan on using?
XT150 for phases, and deciding on 6 pin HiGo for the hall and temp wires.

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Re: Cutting phase wires?

Post by ebike11 » Jan 22 2022 11:00am

E-HP wrote:
Jan 22 2022 10:31am
ebike11 wrote:
Jan 22 2022 10:27am
E-HP wrote:
Jan 22 2022 9:46am
ebike11 wrote:
Jan 22 2022 9:21am
Hi all!
Is it worth/beneficial to, for example, cut the phase wires on a qs273 motor, leaving about 15cm sticking out of the motor then replacing the rest of the long phase wires that were cut with 6awg wire on each phase and crimping everything tight??
Its almost impossible to fit thicker wire through the axle so this seems like the only option at the moment.
Or would the gains be minimal or not worth the effort?
Ill be running over 100V and pretty high amps when in bursts.
Thanks!
I'll probably do that, but mainly when adding connectors near the motor for easier maintenance. I think I'll do some tests with a spare thermistor and CA and see how much hotter they get under high current first, then decide whether to upgrade the wires or just use the stock ones when adding the connectors. By feel, I haven't noticed anything, but they probably cool down quickly, so a probe would give better data. They also sell probes with displays for $10 on Amazon, but I already have a spare thermistor.
What type of connectors will you plan on using?
XT150 for phases, and deciding on 6 pin HiGo for the hall and temp wires.
So where on the phase wires will you install the xt150?

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Re: Cutting phase wires?

Post by E-HP » Jan 22 2022 11:27am

ebike11 wrote:
Jan 22 2022 11:00am
E-HP wrote:
Jan 22 2022 10:31am
ebike11 wrote:
Jan 22 2022 10:27am
E-HP wrote:
Jan 22 2022 9:46am

I'll probably do that, but mainly when adding connectors near the motor for easier maintenance. I think I'll do some tests with a spare thermistor and CA and see how much hotter they get under high current first, then decide whether to upgrade the wires or just use the stock ones when adding the connectors. By feel, I haven't noticed anything, but they probably cool down quickly, so a probe would give better data. They also sell probes with displays for $10 on Amazon, but I already have a spare thermistor.
What type of connectors will you plan on using?
XT150 for phases, and deciding on 6 pin HiGo for the hall and temp wires.
So where on the phase wires will you install the xt150?
Planning on around 4" or so from the hub, but it's a low priority upgrade for me. If I swap out my controller, then I'd probably address is then though, since I'd be messing with the wires anyway.

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Re: Cutting phase wires?

Post by ebike11 » Jan 22 2022 11:31am

E-HP wrote:
Jan 22 2022 11:27am
ebike11 wrote:
Jan 22 2022 11:00am
E-HP wrote:
Jan 22 2022 10:31am
ebike11 wrote:
Jan 22 2022 10:27am


What type of connectors will you plan on using?
XT150 for phases, and deciding on 6 pin HiGo for the hall and temp wires.
So where on the phase wires will you install the xt150?
Planning on around 4" or so from the hub, but it's a low priority upgrade for me. If I swap out my controller, then I'd probably address is then though, since I'd be messing with the wires anyway.
which hub do you have?

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Re: Cutting phase wires?

Post by E-HP » Jan 22 2022 11:39am

ebike11 wrote:
Jan 22 2022 11:31am
E-HP wrote:
Jan 22 2022 11:27am
ebike11 wrote:
Jan 22 2022 11:00am
E-HP wrote:
Jan 22 2022 10:31am

XT150 for phases, and deciding on 6 pin HiGo for the hall and temp wires.
So where on the phase wires will you install the xt150?
Planning on around 4" or so from the hub, but it's a low priority upgrade for me. If I swap out my controller, then I'd probably address is then though, since I'd be messing with the wires anyway.
which hub do you have?
Not a big hub like yours; Leaf 5T, but the stock phase wires are pretty skinny.

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Re: Cutting phase wires?

Post by ebike11 » Jan 26 2022 8:38am

Im thinking to just leave around 15cm of stock phase wires exiting the motor and crimping thicker gauge.
Would going 4awg be super overkill or 6awg??
Motor is QS273 and Ill be putting a lot of wattage through it on "bursts". At least 25kw

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Re: Cutting phase wires?

Post by spinningmagnets » Jan 26 2022 8:50am

Copper wire is pretty cheap compared to the cost of the entire build. I would run the stock wires for a while to see how warm they get.

I dont believe that putting in fatter phase wires outside of the hub will help performance, but doubling the copper cross-section can create a heat-sink to allow the bottle-neck at the axle to run cooler.

Do you plan to run 72V / 20S, or more?

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Re: Cutting phase wires?

Post by ebike11 » Jan 26 2022 2:05pm

spinningmagnets wrote:
Jan 26 2022 8:50am
Copper wire is pretty cheap compared to the cost of the entire build. I would run the stock wires for a while to see how warm they get.

I dont believe that putting in fatter phase wires outside of the hub will help performance, but doubling the copper cross-section can create a heat-sink to allow the bottle-neck at the axle to run cooler.

Do you plan to run 72V / 20S, or more?
Hi there
running 28S or 32S

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Re: Cutting phase wires?

Post by 999zip999 » Jan 26 2022 2:18pm

I remember having my first motor with 5ft phase wires and got really hot. So getting that controller close to the hub and wires as short as possible is best. And had solder on 4mm connectors melt off.

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Re: Cutting phase wires?

Post by spinningmagnets » Jan 26 2022 2:44pm

running 28S or 32S
32S seems to be much more rare than 28S. What charger, BMS, and controller are you using?

I have wondered about using two 14S packs in series as a 28S battery. Possibly with no BMS's.

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Re: Cutting phase wires?

Post by ebike11 » Jan 26 2022 4:34pm

999zip999 wrote:
Jan 26 2022 2:18pm
I remember having my first motor with 5ft phase wires and got really hot. So getting that controller close to the hub and wires as short as possible is best. And had solder on 4mm connectors melt off.
5ft??? For each phase?

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Re: Cutting phase wires?

Post by ebike11 » Jan 26 2022 4:39pm

spinningmagnets wrote:
Jan 26 2022 8:50am
Copper wire is pretty cheap compared to the cost of the entire build. I would run the stock wires for a while to see how warm they get.

I dont believe that putting in fatter phase wires outside of the hub will help performance, but doubling the copper cross-section can create a heat-sink to allow the bottle-neck at the axle to run cooler.

Do you plan to run 72V / 20S, or more?
Yeah im not expecting performance gains besides the gains of the motor/wires being cooler

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Re: Cutting phase wires?

Post by ebike11 » Jan 26 2022 4:43pm

spinningmagnets wrote:
Jan 26 2022 2:44pm
running 28S or 32S
32S seems to be much more rare than 28S. What charger, BMS, and controller are you using?

I have wondered about using two 14S packs in series as a 28S battery. Possibly with no BMS's.
Im using high discharge hobbyking lipos and they only come in 6S and 4S
I went 32S because my 300A ANT bms can go up to 32S.
Im doing all series so I was able to get a 32S charger as well

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Re: Cutting phase wires?

Post by ebike11 » Jan 26 2022 4:45pm

I measured the phases on the qs273..little over a meter from the outside of the motor..around 120cm i think

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Re: Cutting phase wires?

Post by 999zip999 » Jan 26 2022 4:51pm

Yes 5ft I it was for pedicab or something. 130v- 134v Wow

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Re: Cutting phase wires?

Post by ebike11 » Jan 26 2022 7:16pm

999zip999 wrote:
Jan 26 2022 4:51pm
Yes 5ft I it was for pedicab or something. 130v- 134v Wow
Hi yes high voltage but pack range is 20Ah.

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Re: Cutting phase wires?

Post by ebike11 » Jan 28 2022 12:55am

I plan to crimp the stock phase wire to the thicker wore with 1 to 2 cm copper tube pieces.
I assume the current would flow better compared to solder? Plus crimping with guarantee the wores dont come loose

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Re: Cutting phase wires?

Post by Voltron » Jan 30 2022 2:20pm

I did that on my high power cargo bike, and it def made it difference on how hot the wires would get coming out of the axle. It wouldn't seem like that much help, but between the IR² heating from the long skinny wires, and the copper mass of the new thicker wires making a heatsink, it was really noticable on mine. The very short run of the remaining thinner wires still isn't the best, but way better overall re. the heating.

JMO, the closer to the axle the better, mine were just a few inches, and yes on crimps, way more reliable long term when done right. Plus I left each of them not bundled tightly together to look pretty, but spaced from each other and getting lots of airflow right on the insulation
And I'd put a plug on the other end from the motor, even if it means more hassle unbundling the wires for flats etc . Farther from the motor heat, more sheltered from water spray and corrosion, and on my set up the controller was pretty exposed, so easy to reach and feel the plug for heat while riding, where if it gets loose or corroded at the back and starts resistance heating, you tend not to notice it until full meltdown stops you mid ride somewhere. That might not work for a setup that has a lot of internal routing or hard to access controller though...

Just a separate heads up with that high a voltage, use a really well shielded power plug on the battery end. Mine slipped out of my hand when I was removing the battery one time and swung near the aluminum mounting plate, and a spark jumped the air gap, and gouged a 3cm long trench in the plate like an arc welder, until enough of the plug vaporized that it stopped. And that was at 20s...
391.jpg
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Re: Cutting phase wires?

Post by 999zip999 » Jan 30 2022 5:47pm

Yeah that's what I found out the length of the wire makes a big difference I like the idea is separating the three phase wires so they don't hit each other up. I have a Lyen 18fet and wires coming out are big a stock mxus 3,000 wires. I think I will make them shorter as I would have to use 4mm bullets from the controller wires 6in. to 27in thicker gauge to 4mm the 6in of wheel wires. I don't like having two solder 4mm in each line. ??? Just thinking.

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Re: Cutting phase wires?

Post by ebike11 » Jan 30 2022 11:09pm

Voltron wrote:
Jan 30 2022 2:20pm
I did that on my high power cargo bike, and it def made it difference on how hot the wires would get coming out of the axle. It wouldn't seem like that much help, but between the IR² heating from the long skinny wires, and the copper mass of the new thicker wires making a heatsink, it was really noticable on mine. The very short run of the remaining thinner wires still isn't the best, but way better overall re. the heating.

JMO, the closer to the axle the better, mine were just a few inches, and yes on crimps, way more reliable long term when done right. Plus I left each of them not bundled tightly together to look pretty, but spaced from each other and getting lots of airflow right on the insulation
And I'd put a plug on the other end from the motor, even if it means more hassle unbundling the wires for flats etc . Farther from the motor heat, more sheltered from water spray and corrosion, and on my set up the controller was pretty exposed, so easy to reach and feel the plug for heat while riding, where if it gets loose or corroded at the back and starts resistance heating, you tend not to notice it until full meltdown stops you mid ride somewhere. That might not work for a setup that has a lot of internal routing or hard to access controller though...

Just a separate heads up with that high a voltage, use a really well shielded power plug on the battery end. Mine slipped out of my hand when I was removing the battery one time and swung near the aluminum mounting plate, and a spark jumped the air gap, and gouged a 3cm long trench in the plate like an arc welder, until enough of the plug vaporized that it stopped. And that was at 20s...

391.jpg
Thanks for the info
Yes the shorter the phase the better but i have no choice to have my controller bolted to the front side of my EEB frame so after measuring it looks like exactly 1 meter from the motor axle nuts to the Sabvoton.
Therefore, i will go pretty overboard and copper crimp 1 meter of 4awg on each phase to the oem phase after cutting it 10 to 15cm outside the motor.

I noticed new QS motors now has ALL 3 phases wrapped all together and coated with wire insulation to make it look like 1 thick wires coming out of the motor. Older QS motors had each phase loosely coming out ot the axle

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Re: Cutting phase wires?

Post by Voltron » Jan 30 2022 11:39pm

I meant cutting the old wires close to the hub, not moving the controller closer 👍

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Re: Cutting phase wires?

Post by ebike11 » Jan 31 2022 12:11am

Voltron wrote:
Jan 30 2022 11:39pm
I meant cutting the old wires close to the hub, not moving the controller closer 👍
Yes thats what ill do..with 1 meter of 4awg on each phase and without wrapping together as you mentioned

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