First Big Lion build.

[chehorn]

Hey all, first would like to say, amazing forum. I have learned so much from this place and all of its members. Finally made an account to purchase some cells from a member and am now on my way to piecing it together. This will be the first time I will be building such a big lion battery, have worked with smaller lipos before but never welding the cells together with tabs, Wanted to make a post to see if anyone had any advice/corrections for me. Here is the build.

52v 14s6p

Samsung 35E: https://www.imrbatteries.com/samsung-35e-18650-3500mah-10a-flat-top-battery/

Bms: http://tinyurl.com/hvefclp

Nickel strips (will double up on these. thickest width i could find) : https://www.aliexpress.com/item/1KG-Nickel-tape-0-2-7mm-nickel-strip-18650-lithium-battery-nickel-belt-Battery-Spot-Welding/32709048425.html?spm=2114.13010608.0.0.89deOG



Basics for the Battery. Was also going to add two step down converters for different plug ins.

5v: http://www.ebay.com/itm/251623308707?_trksid=p2060353.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

12v: http://www.ebay.com/itm/261569589382?_trksid=p2060353.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

For the actual holding the battery together I'm using standard hot glue, large heat shrink, and xt90 connectors. Let me know what you guys think. Will be posting photos when i get the welder set up.

 

[mauimart]

I am in the process of doing something similar (https://endless-sphere.com/forums/viewtopic.php?f=1&t=85489 ). Here's some advice based on my experience so far:

The nickel strip you have linked in not pure nickel but rather nickel plated steel. It will rust sooner than later. Here is the one I went with.

https://www.aliexpress.com/item/Pure-Nickel-Strip-for-Scientific-research-18650-battery-welding-Size-0-2-8mm/32739610924.html

I can confirm that it's pure nickel. It's also an additional 1mm in width.

I recommend insulating washers on the positive terminal of all cells.

http://www.ebay.com/itm/200pcs-single-joint-18650-hollow-solid-insulation-red-paper-adhesive-cushion-mat-/331833547185?hash=item4d42d219b1

I would be a bit weary of hot gluing the cells together at least at the series connection. If the wrapper is compromised you will get a short. See my thread for the outcome of such a short.

 

[chehorn]

Damn, what I get for hastily buying something. I will be building an enclosure for it so will have to look into making gaskets and using sprays to try and waterproof it to delay the corrosion.

Washers sound like a good idea, the connectors do seem a little close.

Hope your hand is getting better, solid advice on being careful of a short. I will add some additional heat shrink and spacers between the series connections. Unfortunately I'm still working on fixing my 3d printer so i wont be able to build a hard casing for the batteries. Thanks for the advice!

 

[999zip999]

2nd on the washers on the pos end. Those chargers are only 10 watts . That take will a day to charge 24 hours or more.

 

[redilast]

Damn, what I get for hastily buying something. I will be building an enclosure for it so will have to look into making gaskets and using sprays to try and waterproof it to delay the corrosion.

Washers sound like a good idea, the connectors do seem a little close.

Hope your hand is getting better, solid advice on being careful of a short. I will add some additional heat shrink and spacers between the series connections. Unfortunately I'm still working on fixing my 3d printer so i wont be able to build a hard casing for the batteries. Thanks for the advice!

The nickel plated steel shouldn't rust in most environments. If you are in a high humidity environment you may see some rusting after a while. The nickel plating largely prevents it from rusting, but wherever there are heavy scratches in the nickel plating and on the edges and stuff is where it is more rust prone. The biggest difference though is nickel plated steel has 30-40% or so more resistance than pure nickel. But the benefits are its cheaper and generally easier to weld with less power required and less of a chance of electrode sticking.

 

[chehorn]

2nd on the washers on the pos end. Those chargers are only 10 watts . That take will a day to charge 24 hours or more.

Don't believe i posted a charger, Will be using lunacycles 52v smart charger. The 10 watt parts I posted are step down converters so that I can have other voltage electronics hooked up to the battery, have done similar things with other set ups, I believe it should work.

Damn, what I get for hastily buying something. I will be building an enclosure for it so will have to look into making gaskets and using sprays to try and waterproof it to delay the corrosion.

Washers sound like a good idea, the connectors do seem a little close.

Hope your hand is getting better, solid advice on being careful of a short. I will add some additional heat shrink and spacers between the series connections. Unfortunately I'm still working on fixing my 3d printer so i wont be able to build a hard casing for the batteries. Thanks for the advice!

The nickel plated steel shouldn't rust in most environments. If you are in a high humidity environment you may see some rusting after a while. The nickel plating largely prevents it from rusting, but wherever there are heavy scratches in the nickel plating and on the edges and stuff is where it is more rust prone. The biggest difference though is nickel plated steel has 30-40% or so more resistance than pure nickel. But the benefits are its cheaper and generally easier to weld with less power required and less of a chance of electrode sticking.

This is something i was worried about upon further research. According to the ultimate welding guide the steel wont be able to handle the amperage of the cells i have. Will need to get the pure nickel i believe. What do you think?

 

[999zip999]

Chehorn thanks I get it now. Well here's a chance to find out the difference in welding nickel and nickel plate. I think okasha had a chart on welding and resistance of different okasha ?

 

[redilast]

This is something i was worried about upon further research. According to the ultimate welding guide the steel wont be able to handle the amperage of the cells i have. Will need to get the pure nickel i believe. What do you think?

It depends. What kind of current do you plan to draw from this pack? Peak (surge amps) and max continuous amps? Then I can tell you if nickel plated steel will suffice or not.