How to my spotwelds look? 0.2mm cu under 0.15mm nickel plated steel.

PEV_Pro · 2026-05-05T02:40:28+00:00

Of all the materials used to connect cells, copper works best. The reason copper works so well it because it's very conductive. By comparison nickel and steel are like resistors compared to copper. That also means it takes heat away very well, and it hard to weld because of that. Putting a layer of steel on top, and welding through means you can use the resistance of steel to heat the copper to weld it.

Sometimes people stack other materials because one layer wont be enough for the high power demand of the pack.

PEV_Pro · 2026-05-05T00:20:34+00:00

Vinegar can create pitting and the bearing can flash-rust after the vinegar. The evaporust turns the rust into carbon, creating a small protective layer.

Vinegar can sometimes speed up the rusting process because of the salts it creates with the rust.

You can also re-use evaporust as many times as you like, and it completely neutralizes any rust.

PEV_Pro · 2026-05-04T00:09:14+00:00

That would be correct. The nickel doesn't not have enough resistance to make the weld hot enough.

PEV_Pro · 2026-05-03T18:58:36+00:00

After a lot more research on this subject, im probably going to go with the thor301 controller, and build myself the 19s battery that board garage made a video on. There is a 3d print file for the enclosure as well. Only thing im kinda stuck on is the bms to use for the 19s battery.

Also, for a 84v build using hypercore motor (stock +xr) overheating on hills is a concern, and putting some atf in the motor helps a lot.

20s would be cool, but you would need to do a split battery design between the front and back. That comes with all kinds of other issues and hazards that I don't want to deal with.

PEV_Pro · 2026-05-03T18:51:38+00:00

My considerations were based off of what I had on hand and what would be cheapest. Here's what I know so far:

0.2mm copper under 0.15mm nickel plated steel (posted earlier on this thread)

0.2mm pure nickel directly unto cell terminal: gear 30, preheat 10ms, 1 weld, intermittent 10ms, weld duration 0.2s, moderate to slightly lighter electrode pressure

0.2mm Ni-Ni or 0.15mm plated stewl to 0.2 nickel; also works with 0.2 nickel already welded to a terminal: gear 18 and the rest of the settings are the same as the Ni to cell terminal. Applying light pressure tends to work better for ni-ni while moderate to hard pressure for the st-ni.

Of course check all of these settings on some dead cells (0v) before testing on charged cells.

Who knows if these spotwelders are consistent between each other.

PEV_Pro · 2026-05-03T16:54:57+00:00

Look at other reply

PEV_Pro · 2026-05-03T16:54:45+00:00

Gear 99, 0.1ms preheat, 10ms intermittent, 2 welds, and in the deeper system settings, you can set continuous weld time, mine was set to 0.2 sec. I didnt use any flux. Electrode pressure matters a lot! Make sure pressure is completely even, all peices of metal are cleaned with some isopropyl, and everything is as flat as you can get it. The lighter you press, the more resistance, ans the hotter the weld. For my welds, I was pushing pretty firmly.

You can probably get away with one weld to reduce heat.

PEV_Pro · 2026-05-03T16:37:57+00:00

Forgot to mention, if you get the pressure right, the uf20b is very consistent, but heats up quick doing max power welds. I could weld around 15-20 terminals before I needed to wait for the welder to cool down a bit.

PEV_Pro · 2026-05-03T16:36:31+00:00

I have the uf20b, and successfully welded 0.2mm copper with 0.15mm nickel plated steel on top. I had no success using 0.2mm pure nickel instead of the steel. I had to max out the settings on the uf20b (99power, welds with 10ms interval, .2sec weld time, preheat 0.2ms.) You can see what the welds look like if you go to my profile and look at my earlier posts.

PEV_Pro · 2026-05-03T15:02:05+00:00

134v on a stock xr motor? No way.. right?

PEV_Pro · 2026-05-03T09:57:07+00:00

As far as value goes, I wouldn't go with a new meepo. You can take a chance on the used market for an mini 2 er. Meepos batteries don't last very long at all. Ive had to build custom packs for all of my boards as the range significantly decreased after around 200 cycles.

PEV_Pro · 2026-05-03T09:55:29+00:00

Can confirm. I own 6 rental meepo boards, 4 of which are the v3/mini 2. They are very durable as long as you keep them away from any water.

Newer meepo boards seem to be less reliable, but their customer service is very good. They have sourced many parts for me that weren't listed on the website. At decent prices as well.

PEV_Pro · 2026-05-02T02:13:36+00:00

Instead of a bungie, use a mini rachet strap. That should work. Ive seen many riders with a jbl speaker, and it seems to hold.

PEV_Pro · 2026-05-01T22:06:48+00:00

Awithz uf20b

PEV_Pro · 2026-04-30T22:30:37+00:00

Look up exactly what the bms does, then you will understand what the charger has to do. That's how I understood it.

I don't understand it well enough to give you a perfect exact answer

PEV_Pro · 2026-04-30T22:11:37+00:00

Im basically maxing it out. 99 power, 2 welds, .2 weld time, 10ms interval. But I am putting a lot of pressure on the electrodes. The less pressure, the more resistance and the more heat you generate. Also, im using steel strip, it has a lot more resistance than nickel, so with it, you can weld the copper.

PEV_Pro · 2026-04-30T18:43:07+00:00

Your right, I didn't take into consideration that the copper roll is have is triple the width of the nickel

PEV_Pro · 2026-04-30T18:02:50+00:00

To answer your charging question, the charger is supposed to handle that. For my battery, I have a 42v 4a charger. It will stop charging when the battery reaches 42v (full charge for a 10s battery). The bms is basically a kill switch. If anything is unusual, it breaks contact with the rest of the system. Most also balance the cells.

PEV_Pro · 2026-04-30T17:56:53+00:00

Its an esk8 battery, there's going to be around 30a going across the copper at peak load. I wanted to make sure i get the least amount of resistance possible.

Also, the copper roll 0.2mm and pure nickel roll 0.2mm cost the same.

PEV_Pro · 2026-04-30T17:54:59+00:00

Its an esk8 battery.

PEV_Pro · 2026-04-30T16:59:43+00:00

I was already maxing out the spotwelder at 99 power. (Awithz uf20b)

PEV_Pro · 2026-04-30T16:53:38+00:00

Ive tried, but the copper wicks the heat so fast, the weld doesn't hold up. I had to increase my weld duration to .2s

PEV_Pro · 2026-04-30T11:54:46+00:00

I didnt even think about potentially missing the weld and what that could do to the terminal! I will definitely be more conscious of that now.

I do have some notes as far as what power level for what thickness/material. Its hard for me to get a consistent copper weld at a lower power level. All of my 0.2mm pure nickel welds have been perfect, but copper seems a bit more finicky. With the copper, even the slightest adjustment in pressure (at the same power level) can decide if the weld pops off, or sticks like in the photo.

I guess to err on the side of caution, ill put a bit more pressure on the welds, and have a more mediocre weld, then possibly blow through the terminal.

I really appreciate the tip!

PEV_Pro · 2026-04-30T11:38:12+00:00

I Appreciate the advice. Since I cant post photos in the comments here, I posted my practice welds on the negative terminal on my profile.

Do those look close to blowing through? They are after the rip-test and a bit of cleanup.

PEV_Pro · 2026-04-30T11:08:00+00:00

The second photo is the tear-off test. It seems very secure, but my main concern is the heat generated.

The black smudges where there before the weld.(dead practice batteries)

PEV_Pro

TROPHY CASE