Which Crimp Connectors For Overkill BMS?

toms

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Jul 24, 2020
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737
Yes, Iwiss make a ton of different crimpers, unfortunately you really do need to match the terminal/crimper/wire combination precisely.
 

Jacky

New Member
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Aug 11, 2021
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7

Marine Grade Wire & Terminals Vs Automotive Grade​

Through YOUTUBE, I found this crimping terminal video is very effective

520PCS Marine Wire Connectors - Heat Shrink Terminals Specs Ring Fork Spade Butt Connectors, Heat Shrink Electrical Connectors, 12-10,16-14,22-16 Specs Heat Shrink Wire Connector Kit Tinned Red Copper​

, Try click connect

 

Jacky

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Aug 11, 2021
Messages
7
好的,现在我真的很困惑,或者至少我已经清楚为什么我对 @Stepandwolf 和他的问题感到困惑。

我回去看看我从 Overkill 那里得到的原始平衡线束。可能有点难以看清,但如果仔细观察,您应该会发现它是由 AWG 22 电线组成的。
View attachment 59234
为了验证它来自 Overkill,这是史蒂夫对另一端的非常好的密封:

View attachment 59235

并且......让我们回到我们开始的地方!这是我们一直在谈论这些电线末端的环形端子:
View attachment 59237

所以问题似乎是 Steve / Overkill 已经从使用 22 AWG 电线转变为 26 AWG 电线。我不知道为什么,除非是为了节省成本。

船用级电线和端子与汽车级​

[媒体=youtube]fqfqJaxL-uA[/媒体]
通过YOUTUBE,我发现这个压接端子视频很有效

520PCS Marine Wire Connectors - Heat Shrink Terminals Specs Ring Fork Spade Butt Connectors, Heat Shrink Electrical Connectors, 12-10,16-14,22-16 Specs Heat Shrink Wire Connector Kit 镀锡红铜​

,试试点击连接

 

Stepandwolf

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Nov 14, 2020
Messages
635
Yes, Iwiss make a ton of different crimpers, unfortunately you really do need to match the terminal/crimper/wire combination precisely.
I still haven't crimped on my BMS connectors as I kept hoping to find a better solution. Dealing with that super skinny wire is a pain for crimping. Soldering, no problem, but crimping....not so much.
 

curiouscarbon

Science Penguin
Joined
Jun 29, 2020
Messages
1,551
same, when the wire is small i sometimes wrap it around the screwdriver a few times, slide it off, smoosh it flat and the AWG is effectively increased and crimp success encouraged
 

Stepandwolf

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Nov 14, 2020
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635
I have doubled up the wire, tripled the wire, quadrupled the wire, different connectors, different crimpers, and when I am done, I either crimped so hard to smash things into oblivion or the wire pulls right out. Must be me as so many of you succeed without failure, but then even Andy screwed up one of them :)
 

chrisski

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Aug 14, 2020
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2,365
I have doubled up the wire, tripled the wire, quadrupled the wire, different connectors, different crimpers, and when I am done, I either crimped so hard to smash things into oblivion or the wire pulls right out. Must be me as so many of you succeed without failure, but then even Andy screwed up one of them
I have took one of my spare busbars and drilled a hole in it, and used a tap and die set to make a hole for a screw. This method could be used to get an open end connector or other type of connector sized for a 26 AWG wire. I think most of us are having trouble because there is not a 1/4" to 26 AWG open end crimp available, so we take the M6 which is made for a much thicker wire and make do. I have a 26 AWG open end crimper, but when I use it on the M6 crimp, it bends it:

1635015384374.png
That orange tool could crimp a 26 AWG (.14 mm2) crimper, but with the M6 stud, its just to big. A smaller stud or screw would work, it would just have to be screwed into the busbar since it won't fit on the battery stud.

This is how I have decided do 26 AWG to M6 stud on an open end crimper. I don't double and triple bend the wire. I put heat shrink on first because it won't fit over the M6 connector and then using my MC4 crimper with a 2.5 mm2, 4 and 4 mm2 crimper. I crimp the insulation on first, then crimp the wire on. For the insulation, I use the 4 mm crimp, and for the wire I use the 2.5 mm crimp. On the orange tool pictured above anything smaller than the 2.5 mm crimp bends the conector so I use this tool which the second photo shows the crimp size:

1635016306328.png1635016025893.png1635015633943.png
This is still too loose and will pull out. so I take a pair of needle nose pliers and crimp the 26 AWG end so it ends up looking like this:
1635015690213.png1635015719211.png
I then take the heat shrink put it over the wire and heat into place:
1635015794139.png1635015810469.png1635015849835.png
I've done this on the two 25 ah battery packs I am using and have put this on my 280 ah eve cells.

For those Eve's using a BMS, I have pre-charged to less than 3.45 volts per cell, 27.5 volts Absorption Charge, and now that they are at 95% capacity, I will put them in parallel to finish off the top balance at 3.65. This pic is the BMS app from just before taking the 8S 24 volt battery off the pre-charge, disassembling, reassembling in 8P, and starting the top balance at 10 amps and 3.65 volts.
1635016758465.png
I pre-charged these cells to avoid being on the 10 amp power supply at 3.65 volts per week.
 

Batvette

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Feb 25, 2021
Messages
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This is a gross oversimplification of industry practice. Crimping connectors is faster and cheaper than soldering. Crimping must be done carefully and good practices followed; soldering is no different. Crimping CAN be more reliable for fine wire in high-vibration environments like aircraft or automotive, but only IF the properly sized terminal is used. For stationary equipment with no vibration or mechanical stress, crimping THEN soldering with a minimal amount of solder (don't let it wick inside the wire insulation) can give the most reliable connection--especially if the crimp terminal is larger than the actual wire diameter.

The point is to exclude oxygen and moisture while allowing flexing and thermal expansion. Always allow some slack in the wire. Very tightly harnessed wiring with no slack is a bad idea generally, except in very specialized applications.
This.
Several other points.
Teaching new production employees to solder is costly.
In addition, the personal hazards and environmental risks from lead is a down the road liability companies are increasingly loathe to accept.
Most that argue soldering is bad because it breaks wire, etc, you find that they have no experience with it, or do it poorly. I wouldnt consider crimping eye terminals in any application without soldering, and never use that lead free ****.
But then I have likely soldered in the tens of thousands of connections in 40+ years, never knew of one of them that went bad.
 
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Batvette

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Feb 25, 2021
Messages
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Heres a crude image of what i did with my jbd bms harness. I didnt have black heat shrink in the right size so the negative is wrapped in 3m super 88, thats the only tape I use. Id have preferred sealant impregnated heat shrink but this will do. The grey jacket is some very cool silicone covered fibreglass aerospace grade stuff a local surplus place had for 25 cents a foot I think. Got some bigger stuff too. Anyone in san diego area, thats k surplus in national city. The terminals from willys electronics also in nasty city. And yup folded the wire and soldered after crimping them in the classic m shape with an old pair of GB staking pliers. If youre soldering you can crimp them in a vise or pounded with a hammer and it doesnt matter. I actually run a little solder up the wire in cases like this to transfer the stress point away from the crimp because the wire gets pinched by the crimp and strands are already weakened.
Due to the high quality jacketing and heat shrink holding it to the terminalvl these will be plenty durable.
Finally note that all five wires are equal length, making them electrically, if not aesthetically, equidistant in the circuit. This should make the BMS sensing of the cells more accurate than cutting each to length for tidiness.
20211025_023709.jpg

I wasnt real thrilled about the way they will hang down in my cell enclosure and they have to reverse back up so I jacketed them close to the plug and coated the whole affair with clear amazing e6000, in a bent position.
 
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