2x 7s10p in Series (Triangle Pack)

Batteries, Chargers, and Battery Management Systems.
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doomy   10 µW

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Joined: Feb 07 2018 11:39am

2x 7s10p in Series (Triangle Pack)

Post by doomy » Feb 14 2018 5:16am

Hello everyone,

This is going to be my first Pack and it would be great if you could give me some input on how i can improve it.

I plan on using it with a BBSHD motor so max 30A current draw.

My Cells are recycled Sanyo NCR18650GA.

The pack will be seperated in 2x7s because i want to balance charge it with my iCharger 208B.

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I use a DIY microwave transformer spot welder with 15ms preweld and 30ms weld setting.

I have bought 0.15x10 and 0.15x25 pure nickel strips.

Plan on using the larger strips for the rectangle pack and some for the triangle pack where the space allows it.

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Will post more pics while the build continues.

Thanks!!

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doomy   10 µW

10 µW
Posts: 6
Joined: Feb 07 2018 11:39am

Re: 2x 7s10p in Series (Triangle Pack)

Post by doomy » Feb 15 2018 9:07am

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I just glued the triangle pack together with hot glue. I was scared somtimes that the nozzle could burn trough the insulation when i glued the strips in the jig. This was luckily not the case tough.

The hot glue gets hard very fast and when i tried to glue the second row to the first row it was not completely straight. I had to use force to separate the batteries again and tore off some of the heat shrink from a few batteries.

I continued gluing the rows together first and then just placed them where they should go and tried to fill the holes between the batteries. This was no good because the surface area of the glue was too small and it was very messy. You can see it from the 2nd to 3rd row.

I then just placed the pack in front of me, prepared the row so i can just flip it up to the pack, quickly put some hot glue on it and then flipped it up and pressed it to the pack. This worked quite well.

So the pack is ready for welding now.
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doomy   10 µW

10 µW
Posts: 6
Joined: Feb 07 2018 11:39am

Re: 2x 7s10p in Series (Triangle Pack)

Post by doomy » Feb 27 2018 5:54am

Yesterday i contuinued with the build, the spot welding came out nice.

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I had some problems soldering the power leads.
My soldering iron is 65w and its not enough to quickly solder the AWG 12 cables to the nickel. I have ordered a 100w iron now and will try with this one.
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doomy   10 µW

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Joined: Feb 07 2018 11:39am

Re: 2x 7s10p in Series (Triangle Pack)

Post by doomy » Mar 07 2018 4:07am

Finishing touches:
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EbikeAus   100 W

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Joined: Feb 04 2018 5:58am

Re: 2x 7s10p in Series (Triangle Pack)

Post by EbikeAus » Mar 16 2018 5:15am

Looks like a good job!
Hows the pack going?
Were these cells from power tool packs?
Choose LiFe 8)

May all your batteries be fully charged and perfectly balanced :P

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doomy   10 µW

10 µW
Posts: 6
Joined: Feb 07 2018 11:39am

Re: 2x 7s10p in Series (Triangle Pack)

Post by doomy » Mar 28 2018 3:56am

Thank you ebikeaus, the pack is working fine other than my icharger that blew up when i first tried to charge my pack. So now i'm charging it in parallel with my IMAX B8 charger with cheali firmware installed. It takes a long time at only 5A so maybe i will invest in a bulk charger and only balance from time to time.

The cells are from disposed ebike batteries that had only their bms fail. Other than the cells stayed charged at 4.08 for a long time, they are in a great state.

I built another battery with LG HE2 cells for a small saddle bag in a 2x 7s2p (14s2p) configuration.
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