Extending battery cable with crimps, avoid?

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Lovelock   10 W

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Extending battery cable with crimps, avoid?

Post by Lovelock » Feb 27 2019 2:44pm

Hi, I have a new 52v 6ah battery that will be used at 20a max.

The power cables are slightly too short so I've used some of the same cable (12 awg) and connected it with basic B&Q / Home Depot crimps.

I have been shortening all the other cables by solder, but these 12 awg wires are like thin hairs and I can't get a decent connection between them to solder?

Will the crimps be okay? Or should I look at other ways to link the wires before soldering?

Using the NASA method just pushes them apart and they spread because so thin, wrapping round eachother gives a massive bump in size.

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e-beach   1 GW

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Re: Extending battery cable with crimps, avoid?

Post by e-beach » Feb 27 2019 10:04pm

As far as the durability of the amp draw, the only way to really know is by trying it.

I never liked the way crimps worked. Some people use them a lot. I have had a lot of them fail. They can vibrate loose, and the wires can fray where the crimp ends.

I prefer to crimp then solder them, then apply a few layers of shrink tubing to keep the wires from fraying from vibration where the solder ends. When one solders something like a crimp, the failure point is where the solder stops and the copper starts.

My first notion would be to replace the whole length of wire. If replacing the whole wire is not possible, then I would crimp and solder and shrink tube with several layers so the wire does not stress where the solder stops.

:D :bolt:
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Current Build: ProFlex 757 Expert full suspension. Yescomusa 36v 800w Rear DD, upgraded 10AWG solid core through axle phase wires. 15ah Headway, 1000+ cycles, 80% DOD 30A Tronsung controller.

Past: Trek 4500 Yescomusa 36v 800w front DD.
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Chalo   100 GW

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Re: Extending battery cable with crimps, avoid?

Post by Chalo » Feb 27 2019 10:50pm

Crimping can be the best method of connecting wires, or barely better than twisting them together. If you use the correct crimp fittings and a good crimper, it's second only to having no interruption in the wire at all. It's certainly better than soldering alone.

I have used crimp plus solder lots of times, but only when using pliers/vise/incorrect crimper/shabby crimper to do the crimp. If you do that, tie the affected portion of wire down so it won't articulate.
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Lovelock   10 W

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Re: Extending battery cable with crimps, avoid?

Post by Lovelock » Feb 28 2019 6:06pm

Thanks for the replies, I'm currently using these: https://www.diy.com/departments/b-q-blu ... 108_BQ.prd

Which I know wont be that great! I'm going to look at some higher quality crimps and see what I can do.

I'm pulling hardly any power, <500w unless im using throttle and even then its blips of 20a but I want some thing robust.

Sadly the battery is all heat shrinked up etc so no way to refit longer cables.

Any suggestions for really good quality crimps? Or just make sure that they are nice and tight, potentially tin the cable too?

Choppa66   10 W

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Re: Extending battery cable with crimps, avoid?

Post by Choppa66 » Feb 28 2019 6:48pm

Lovelock wrote:
Feb 28 2019 6:06pm
Thanks for the replies, I'm currently using these: https://www.diy.com/departments/b-q-blu ... 108_BQ.prd

Which I know wont be that great! I'm going to look at some higher quality crimps and see what I can do.

I'm pulling hardly any power, <500w unless im using throttle and even then its blips of 20a but I want some thing robust.

Sadly the battery is all heat shrinked up etc so no way to refit longer cables.

Any suggestions for really good quality crimps? Or just make sure that they are nice and tight, potentially tin the cable too?
Hi, those crimps should be fine. I tend to strip back the outer twice along as you need and then twist and fold wire back on itself,making the inner wire twice as thick if that makes sense? If the hole in the crimp will allow that of course? Also use a good quality ratchet style crimping tool and use the correct colour slot for that colour crimp so as not to damage it. Can always put some heat shrink over the crimp to. Crazy price to from b&q for 10!! Can get a pack of 100 from screwfix for a fiver! Wicked seing as b&q supposedly own screwfix! They will always come in handy.

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e-beach   1 GW

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Re: Extending battery cable with crimps, avoid?

Post by e-beach » Feb 28 2019 8:28pm

Weather you crimp only, or crimp and tin, the key is not to let the wire flex where the crimp and copper wire separate. That would be where the wire frays.

To know if they are working well enough, go WOT up a good hill so you reach 20a for a little while, stop the bike and feel the crimp to check if it is hot. If it is really hot, then it is a problem. If it is barley warm or not warm at all you are fine.

:D :bolt:
Favorite Quotes:
"This is L.A., sugar. There is no 'over the top." Chris Erskine
"At a certain point the entropy wins." Maria Helena Braga

Current Build: ProFlex 757 Expert full suspension. Yescomusa 36v 800w Rear DD, upgraded 10AWG solid core through axle phase wires. 15ah Headway, 1000+ cycles, 80% DOD 30A Tronsung controller.

Past: Trek 4500 Yescomusa 36v 800w front DD.
Liahona, Yescomusa 36v 800w generic front DD.
1992 Trek 800, Yescomusa 800w 36v front DD.

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