Inspiration to build Solderless battery

Batteries, Chargers, and Battery Management Systems.
john61ct   100 GW

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Re: Inspiration to build Solderless battery

Post by john61ct » May 29 2019 8:49am

Just using the conductive adhesive idea with permanent hard-wired intra-bank connections may not be worth it, since apparently proper spot welding causes no loss of lifetime cycles.

For me the holy grail is easy per-cell monitoring / diagnostics and (again, **easy**) periodic replacement of weaker cells as needed.

Thus allowing the use of cheaper per Ah, even secondhand cells with better overall results and less wasted time tearing down & rebuilding.

My general solderless thread

https://endless-sphere.com/forums/viewt ... 14&t=99213

Never did get feedback on

http://batteryblocs.com

vruzend I think is a no go, for me personally

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amberwolf   100 GW

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Re: Inspiration to build Solderless battery

Post by amberwolf » May 29 2019 3:51pm

laerciohj wrote:
May 29 2019 7:06am
I think the problem with this is that high discharge lithium batteries tend to get hot, this could melt the grease and remove it from the pole.
If the batteries get hot, then there either aren't enough of them in parallel, or they have too high an internal resistance.

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Chalo   100 GW

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Re: Inspiration to build Solderless battery

Post by Chalo » May 29 2019 11:17pm

amberwolf wrote:
May 29 2019 3:51pm
laerciohj wrote:
May 29 2019 7:06am
I think the problem with this is that high discharge lithium batteries tend to get hot, this could melt the grease and remove it from the pole.
If the batteries get hot, then there either aren't enough of them in parallel, or they have too high an internal resistance.
I've never observed a lithium battery become hot during normal discharge. Plugs, sure. Motors, sure. But not batteries themselves. I think you have to abuse them to make that happen.

The cell contacts in a battery like we're discussing could easily become hot if they have inappropriately high resistance to begin with.
This is to express my gratitude to Justin of Grin Technologies for his extraordinary measures to save this forum for the benefit of all.

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liveforphysics   100 GW

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Re: Inspiration to build Solderless battery

Post by liveforphysics » May 29 2019 11:24pm

Many good greases don't slump or run a bit clear beyond 120-150degC (250-300degF).
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Chalo   100 GW

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Re: Inspiration to build Solderless battery

Post by Chalo » May 29 2019 11:27pm

liveforphysics wrote:
May 29 2019 11:24pm
Many good greases don't slump or run a bit clear beyond 120-150degC (250-300degF).
The grease I use in the guns at the bike shop (Lucas Red 'n Tacky #2) has a drop point of 500F. I have no idea what its electrical conductivity is like.
This is to express my gratitude to Justin of Grin Technologies for his extraordinary measures to save this forum for the benefit of all.

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liveforphysics   100 GW

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Re: Inspiration to build Solderless battery

Post by liveforphysics » May 29 2019 11:31pm

Chalo wrote:
May 29 2019 11:27pm
liveforphysics wrote:
May 29 2019 11:24pm
Many good greases don't slump or run a bit clear beyond 120-150degC (250-300degF).
The grease I use in the guns at the bike shop (Lucas Red 'n Tacky #2) has a drop point of 500F. I have no idea what its electrical conductivity is like.
The grease at your shop likely works fine. The only issues you run into is some plastics absorb the oils out of the grease leaving it crumbly after a long time. If you do a plastic compatibility test with your grease and it doesn't swell it or soften it, it's likely a fine grease to use. Sometimes the best options aren't greases but single ingredient gels that can't separate.
Each carcinogen vapor exposure includes a dice roll for cancer.

Each mutagen vapor exposure includes a dice roll for reproductive genetic defects in your children.

Each engine start sprays them into a shared atmosphere which includes beings not offered an opportunity to consent accepting these cancer experiences and defective genetics life experiences.

Every post is a free gift to the collective of minds composing the living bleeding edge of LEV development on our spaceship.

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fechter   100 GW

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Re: Inspiration to build Solderless battery

Post by fechter » May 30 2019 9:16am

I've used silicone "high vacuum grease" which is just a very thick silicone oil. It does tend to spread a little over time but seems to do well long term. I use it on connectors to keep water out. I noticed the cable company guys use a similar looking stuff on all their outdoor connections.
"One test is worth a thousand opinions"

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Re: Inspiration to build Solderless battery

Post by john61ct » May 30 2019 9:52am

The two compounds I plan to use

A. electrically conductive adhesive, likely silvered epoxy

to hold the tinned copper strands against the cell ends, also flexible rubber buttons like short speaker feet squeezed by the clamping force of the case, likely aluminum. Also acts as a cushion against shock / vibration.

B. dielectric sealant that is thermally conductive

to "pot" the wired ends, physically hold the batteries in place, fully seal the connection, conduct any heat to the outer case.

EPDM rubber, round strip between the "bare batteries block" shoulders and the outer case along its corner, further cushioning against shock / vibration.

May otherwise fully pot the interior if that seems beneficial, e.g. physical restraint, maybe additional shock / vibration dampening

but the case will be sealed watertight anyway.

The thermal issue doesn't worry me much, least of all toward the middle of the cylinders.

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Chalo   100 GW

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Re: Inspiration to build Solderless battery

Post by Chalo » Jun 01 2019 1:12pm

I hope you're not taking about having adhesive on the battery contacts. Conductive glues tend to be like conductive paint-- only conductive when you compared them to insulators, but not nearly as conductive as a metal. They can easily interfere with direct contact between the battery and the wire.
This is to express my gratitude to Justin of Grin Technologies for his extraordinary measures to save this forum for the benefit of all.

john61ct   100 GW

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Re: Inspiration to build Solderless battery

Post by john61ct » Jun 01 2019 2:12pm


Chalo wrote:I hope you're not taking about having adhesive on the battery contacts
see #19 & 20 above

specialized silver-filled sealant / adhesives

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Re: Inspiration to build Solderless battery

Post by 999zip999 » Jun 02 2019 7:01am

Yes silver would seem the way for the best conductibility. It does tarnish ?

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Re: Inspiration to build Solderless battery

Post by Matador » Jun 02 2019 4:27pm

laerciohj wrote:
May 28 2019 9:41pm
I used the vruzend kit and I do not recommend it. The connector of each module has poor spring function, often I lost connection in some cells. I suggested to them that they put copper alloy springs in place, but they ignored it. The vruzend kit is not trusted to maintain connection to cells. I made modifications to the modules: I added springs, copper wire and connector with ball of aluminum foil wrapped in the tip of the copper wire. In my test supported more than 5A for several minutes without any relevant heating, below 30ºC.
I remember being the first to suggest this idea to Vruzend when the kit came out back in early 2017. I even made a drawing of my idea:
https://endless-sphere.com/forums/viewt ... 5#p1277444
https://endless-sphere.com/forums/viewt ... 0#p1286125

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john61ct   100 GW

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Re: Inspiration to build Solderless battery

Post by john61ct » Jun 02 2019 4:57pm

999zip999 wrote:Yes silver would seem the way for the best conductibility. It does tarnish ?
embedded in epoxy?

laerciohj   10 mW

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Re: Inspiration to build Solderless battery

Post by laerciohj » Jun 06 2019 3:27pm

Hello guys!

After assimilating your considerations I have been thinking of ways to improve the support I would like to use and believe that I have solved the flexibility problem well.

With the use of steel springs, I got more than 2 mm of expandable space inside the holder and maintain enough pressure to maintain the connection.

Tip: Before I used round head screw, but they are more bulky and left little room for expansion. The tip is to use straight spindle, it looks excellent. As additional work I will have to shave the head of the screws, but it will not be something hard with a sander.

Note on the outside that I use two nuts, one to limit how much the bolt can force the cell in case of trepidation, so no matter how much I force externally, there will be no force against the cell, and another nut to attach copper wire or plates of nickel for the connections between the cells.

I'll use grease to seal the connection or even insulation tape, that part I think will be the easiest to solve.

See images and video of the new version of solderless support enhanced with your tips.

Tips and guidelines are always welcome!

Thank you!

https://youtu.be/TWn6qwAo9pU

https://youtu.be/Uk7VPVhPUdU
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inCollage_20190606_172307558_compress53.jpg

999zip999   100 GW

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Re: Inspiration to build Solderless battery

Post by 999zip999 » Jun 06 2019 9:11pm

How about some conducted cream.

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Re: Inspiration to build Solderless battery

Post by laerciohj » Jun 07 2019 11:52am

I believe that if a nickel coated bolt is used it would solve the oxidation-reduction problem that leads to surface corrosion. Nickel plated and brass screw has pretty much the same low price.

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Re: Inspiration to build Solderless battery

Post by laerciohj » Jun 07 2019 9:29pm

In this other example a solderless support for four cells. In this case I will use only one spring.

There is difference in the quality of the plastic of these supports. In the previous example the holder has a smaller internal space and the friction is larger, the plastic is different. This makes the cell slide little and it needed springs from the sides. In that other, which is another manufacturer, is little friction and a spring is enough to force the contact the two poles of the cell. For anyone who uses the technique will depend on luck with the quality of the plastic and may need springs in only one pole or both.

Really a straight head screw is more interesting. It allows more space inside the holder and larger contact surface with the pole of the cell.
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