The Sunkko 788H: BZERP BZERP

People ask me what welder i use on my packs. This is her.

It’s a Sunkko 788H I got from a dude in Chicago over ebay and its been the shit for about a year now. I also own a 709A but i feel like the 788H works better on the heavier nickels.

So far i’ve been able to do both 0.15mm as well as 0.2mm in pure nickel when i crank it way up.

Anyone else building packs with one of these and what are your thoughts? Got any mods to share?

I know they’re all great and everything those Sunkkos… but I’ll stick with my £20 DIY build… :wink:


i’d love to know what happened to the arduino based spot welder i ordered. It never showed up.


I run a hakko carbon filter above my spot welder to extract those nasty fumes. I also use a hood extractor above the workbench/welding station. Something left over from my days tig welding stainless

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I use the same spotwelder but with the ‘wand’ you cant use as thick nickel but its a hell of a lot easier to use.

there has to be a quick and easy solution to that. Fatter cables and a transformer mod maybe?

I just use multiple layer of nickel but we both know its a lot more work

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That’s happening this year. I’m designing an exhaust vent system that will basically blow everything through the roof. Vents over the welding and soldering spaces as well as the building stations, all ducted into the attic and ejected outside through a few filters with room air intake happening at close to floor level.

other things on the list for 2018 include a steel deck press, a proper cage with dust management for Shirley (my xcarve), air conditioning inside the shop, reframing the attic over the shop for storage and better electrical, and a raised floor with removable tiles for cable management and air return. and a Galaga machine.


I used the diy arduino one, works great with .15mm.


That’s the one i ordered that never showed up.

Do you have a link to where you got yours? I want to modify my 709A with it.

@longhairedboy I’m in the UK so got mine from . Fast shipping as well. I never used the pedal, I found that the auto welding function works great: touch the copper terminals and 2 seconds later it welds.

I’m using it with a 440cca car battery but even high discharge lipos work great for .15

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Here’s a sample:

I use the 788 too, no complaints other than having to wait for cool down if doing a lot of thick nickel I find keeping the tips clean is KEY to good, consistent welds

true. I keep a popscicle stick wrapped in sandpaper nearby to rub the tips.

I have found that waiting a few seconds to let things cool helps a lot too. If you don’t the tips gnarl quicker.

Can you share link to that Chicago seller page on eBay or share eBay store name? Thank you!

Im running a 788h because it was the cheapest I could find at the time… no complaints here. Just have to run it on a 20A dedicated circuit or else it sometimes will flip the breaker.

What cool down? I don’t remember having to wait for a cool down period.