[LithiumaniacsEVRacing]

Well, now that I have battery packs flowing in like rabbits. I decided to dissect one 10S pack. I like the welded tabs and the secure pouch structure. The wires are too small and needs to be upgraded.

The company placed one 5S pack on top of another 5S pack to create the 10S 37V. I am waiting for my battery guy to get his packs so we can design the special BMS. But, I will play with them until then.

 

[LithiumaniacsEVRacing]

I have separated a 5S pack to inspect tabs for all possibilities. My battery guy wants to design the BMS system keeping the packs in 5S. As long as we upgrade the 12 gauge wires to a larger grade. We are sticking with the smallest but safest size. He recommends keeping the wires warm for best results. He has a system for wire size/amps/heat/time. Way above the basic system for amps to size.

I could reweld the pouches into parallel packs of 5P, but he said it is not needed with his BMS system. He will get his packs anyday and his testing will begin. They are rated at 45c to 90c.

 

[LithiumaniacsEVRacing]

The goal is the replace all the wires on the 5S packs and parallel into 25AH or 50AH rows. I am not sure of the final design yet until his testing and final results are completed. The battery design and pack will depend on his findings. Our goal is to have a 5000amps to support both controllers.

 

[DavidDymaxion]

Pics?

Jack Rickard had a case where the LiPo pouch was electrically active -- are you going to electrically insulate the boxes?

The goal is the replace all the wires on the 5S packs and parallel into 25AH or 50AH rows. I am not sure of the final design yet until his testing and final results are completed. The battery design and pack will depend on his findings. Our goal is to have a 5000amps to support both controllers.

 

[MN Driver]

Pics?

Jack Rickard had a case where the LiPo pouch was electrically active -- are you going to electrically insulate the boxes?

Jack Rickard has never used LiPo. He was talking about someone else who used Kokam packs.

Turnigy cells are shrink wrapped and not separate and exposed, so this shouldn't be an issue.

 

[frodus]

The issue with one person I know of that used LiPo was that the ends where they crimp them together, are cut foil. The edges could electrically conduct and actually shorted out cells because they touched the cases.

The packs are shrinkwrapped, but he's taking them out of the shrinkwrap I assume..... so the cell edges could be exposed. Its not an issue for most people because they keep them in the packs, which are wrapped in plastic. If he intends on using them in a box, or putting them edge to edge, he's going to need to insulate.

look here:

 

[MN Driver]

So the entire pack is plastic shrink wrapped or is it some sort of metal vacuum pack?

Seems to be the same cells, pictured here and it was assumed that the pack was electrically insulated and as far as I know the only change was to punch a hole in the terminal to secure the cell.
http://www.metricmind.com/audi/images/_0227_stack.jpg

 

[frodus]

read my entire post.

the ends where they crimp them together, are cut foil. The edges could electrically conduct and actually shorted out cells because they touched the cases.

The case that metricmind built were metal. The crimped edges shorted to the metal case. Stacking them is fine, they're insulated. But put them next together where the crimped edges touch something else that is metal or has an electrical potential, and you create a short.

 

[LithiumaniacsEVRacing]

I am still waiting for my battery tech to receive his packs of Turnigy. Once he has tested cell tab size, wire, etc....we will know if we can keep the wires and packs intact. What ever the final verdict will be, the packs will be wrapped. We might have to add additonal packs in parallel to use the smaller wires, many unknowns at this point. I dissected one pack just to see their engineering skills in China, my opinion all welds were done nicely! But, who am I?

 

[LithiumaniacsEVRacing]

 

[LithiumaniacsEVRacing]

 

[LithiumaniacsEVRacing]

 

[LithiumaniacsEVRacing]

 

[LithiumaniacsEVRacing]

 

[LithiumaniacsEVRacing]

 

[frodus]

by welds, you mean solder.....

 

[LithiumaniacsEVRacing]

 

[LithiumaniacsEVRacing]

 

[LithiumaniacsEVRacing]

 

[LithiumaniacsEVRacing]