18650 battery Kit development and discussion[testing done]

agniusm said:

I am just amazed, how there is none such kit available on the market, surely Chinese are scanning these forums as well

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That's two of us! I hope someone is! The links above show there is someone thinking. I'm going to try to see if there is a chance for a group order. I really like the design! WOW!

riba2233 said:

Just give me some time to track down the link.

EDIT: Ok, here it is. Wireless design But if I see it well, they still have to weld the positive side of cells which are on topmost position.

http://akbattery.en.alibaba.com/productgrouplist-220504360/48V_Series.html

http://akbattery.en.alibaba.com/product/1526882743-220504360/48V_40Ah_High_quality_Lithium_Motorcycle_Battery_Very_safe.html

http://akbattery.en.alibaba.com/product/1468356473-220504360/48V_40Ah_E_scooter_E_motorcycle_Special_vehicle_Rechargeable_Battery_Pack_Lithium_Ion_Battery_Pack.html

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This company has a representative in the USA. I'll be speaking with them this afternoon about the solderless system.

Great, tell us the results!

Well China you know, is on vacation. However I just got some stunning prices, low, for LifePO4 packs. More to come.
They are on it and promise results on the solderless system parts for 18650. I'm told the parts ARE available. Now we wait for the New Year to end. First week of March for any solid answers but I'm locked in...

We should entertain a battery group buy come March. Certainly a group buy on the solders system components. Again, I'm amazed at this USA companies price point. I'm VERY positive. There may be a wheel and no need to reinvent it!

Interesting. Would be good to have some close ups as its not clear what they do at the negative end. It looks like spring tab. One concern is that spring tab. You better have it on the side cause the more cells you put on top, the more presure pushes on bottom cell, unless there is a ring stop. Its still not the same what I have imagined. You still need enclosure.
Damn, I have spent some time getting new drawings which eliminate 18650 holders. Will do 10S6P and will get it 3D printed, hopefully diy some copper tabs to see if it will work at all.

They do enclosures as well. Waiting for more answers. Unfortunately their primary design is not eBikes and some of the sizing is odd IMO. BUT the information, as you noted, is still sketchy.

I am waiting for a confirmation on their LifePO4 36V 10Ah packs too. Knowing the "power rangers" <tongue in cheek> here aren't much interested but I am, and a few others lie myself are, interested in a pack that's good for 2000 charges to 80%.

Time will tell, damn if this didn't have to be found during the New Year/Spring shut down.

I still do not understand how exactly it works. I see the theory but physical pressure needed?

parabellum said:

I still do not understand how exactly it works. I see the theory but physical pressure needed?

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tomjasz said:

Waiting for more answers...

Time will tell....

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Looks like for the negatibe side plastic tray has a metal insert grab the cell firmly, hence the cut shrik tube. Positive side has a metal spring. Negative and positive trays/holders are conductive at the top as well. I just dont see how it is all attached together and all, perhaps through some of those vent holes. Conductor plate is for series connection to loop back. Might be over engineered.

tomjasz said:

parabellum said:

I still do not understand how exactly it works. I see the theory but physical pressure needed?

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tomjasz said:

Waiting for more answers...

Time will tell....

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Anyway weigh and volume figures are far better then my build. Hope that current rate will not disappoint.

Any update on these? seems like a doable idea...

So far got quote for punch making copper plates, 3000eur. Not gonna happen at those prices. Will look to east

So i had a bit of time to play with this no solder/weld concept. I had a lot of thinking about it during past months and decided to give a shot at modular 18650 design. I am working on 4P module, not intending to make 5p or 6p. It will work as 8P though. Not to talk too much, photos talk best.
This is the first attempt:





Then i thought i will try something screwless, the printer is at work now and i will have prototypes tomorrow:





I have left out copper tabs, but the idea is that those will have longer strip that will fold on dowetail joint and then slide together making connection with posibility to solder at the end of the strip. I am thinking of nickel plating them to avoid oxydation. Channels in the lid are made for balancing connectors to be attached and hiden with the diy lid of the whole pack.

My last prototype allows to form different shape batteries, also it is possible to join two main bodies together to form tube like battery pack.
I am looking to make it as simple as possible with as few pars as i can.
At the moment there will be 3 different parts, main body, lid, copper plate. I envision that i would open online service to purchase separate parts so anyone could build their pack as they like and not be limited by whats available. Its not for the power bikes but i think it will be good for low to average power builds.
There will be some DIY needed with connectors and protection boards (another part that i have in mind is plastic box with dowetail connectors to attach to the battery)
I have not yet looked into manufacturing of this kit but i will sure to try my best to make it happen.
I will also continue working on the 10s and 14s 6p ready battery kits which will require only cells of your choice. I need to refine my design and print out prototypes to see how all fits and looks.
Thanks for visiting.

P.S. FDM printing is just for prototyping, if the kits will see daylight they will be made using industrial methods.

Watching closely. I still think a rebuildable compression pack would be a HUGE success, but money talks, bullshit walks...

Yes, it will be rebuildable, cell swappable compression module

Thinking now on electroplating copper to eliminate unwanted galvanic corrosion. What would be the preferred coating? Would it be nickel, tin or perhaps silver if its cost is reasonable?

Hi Agnuism,

When I did this I went with Tin. I wanted silver which I gather would be the best choice, but the cost was very high. I went with Tin over Nickel on the advice of the plating people, but they came back looking awful, hugely disappointing after the cost and effort I went to making the contacts. Perhaps they were careless, and I suspect this is the case but I wish I'd gone with Electroless Nickel with another firm at about the same cost now. FWIW, I think that would be my choice if I were to start over.

Regards,

Jason

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After:

Yeah, that does not look professional and perhaps they did not lean thm properly. The question is mostly about conductivity. I know silver would be the choice but the cost is in a second row. I wander what nissan leaf busbars are coated with, it does look like shiny tin.

agniusm said:

Yeah, that does not look professional and perhaps they did not lean thm properly. The question is mostly about conductivity. I know silver would be the choice but the cost is in a second row. I wander what nissan leaf busbars are coated with, it does look like shiny tin.

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Nickel is more conductive then tin.

Any recommendation on test cell? I need 60-80A cell @ 6P. I am not fussy on capacity but 2.3-3.0AH is the range, perhaps i could go as low as 2.1AH. The cheaper the better.

Samsung 25R or Sony VTC5.

Thanks

Sony VTC4 is lot cheaper, 2.1 Ah 30 A cont, and heats less at same current (unless you want to test cell that heats more on purpose )

Slow but going forward. 4 months ago i had a baby girl and things were slow on this end, but never the less i find some time to continue working on this battery kit. I have nearly finished my test kit and would like to share some of the parts.
Here is a bus bar for 6 cells in parallel:



They were milled out of flat copper sheet, got few made:



I made rude punch and die to get those nipples done:



Its OK for the test kit, but production will be more uniform and smooth:





Small tab is for balancing harness:



I have cut some Rogers Poron, it will be required for one side of the battery. I will most likely change it to low set silicone, it has better working temps and compression set rate is lower:



I have tested POM material for top and bottom but it deformed after machining:



Just tested if all fits and i have no errors:



At the moment new covers are made from Tufnol(Novotext). Its more rigid, has working temps of -40 to 120C (compared to POM -50 to 105C). The downside is that it does not look as nice:



I will be offering 2 sizes, 10S and 14S. It will be possible to produce any Series kit in 6P (standard) configuration at extra.