New batt pack- 8s4p Basen 26650

Sorry @Namasaki. My bad. I thought that was what you meant in your last post when you said you believed a 60a battery was just not adequate for hill climbing.

People are buying 30q cells from nkon with good results. Looks like it would have been cheaper too

Ok. Received welder. It is a Sunnko. A 788H model. Got for $120 after negotiating on eBay.

that is a pretty solid deal. I just got a sunko709a. If you find a spot selling pure nickel strips, please let me know! I have had no luck so far.

This one I can vouch for, it’s what I bought.

Not sure about this one though…

I’m with @Namasaki in recommending high amp/current batteries whenever possible. it’s why i’ve avoided 18650’s for so long, because high C lipos were just a better match for me. (40-60c rated lipos)

I’m delving into 18650’s now to be like the cool kids… I have a 3p HG2 setup in process which i expect will work well for mostly flats, and a VTC5a pack TBD (3 or 4p). I’ve also been doing some testing to determine my true current consumption when riding. Using an eagletree logger i have seen much less current draw than expected. Peaking to around 46-50A on a single setup. I’ll do some more testing w/ some VESC Sixes since they have a higher current limit to see what my real-world worst case current draw would be - and then i’ll overbuild from that measure.

I’m not a normal sized human (6’8"/2m - 265lbs/120kgs’ish) - on ‘The Suga’ (guest board) - 149kv 8s2p 60c (2x8s 5.8Ah 30c parallel) - i saw 51A peak:

(i have a nice bike path across the street and did a quick 4’ish miles with a couple nice long gradual hills, and a short steep one behind me i tried to stress it) Most boards won’t take me up, it did though slowed down midway to top.

On my GF’s Vanguard - 190kv 8s 30c (2x4s 8Ah) - i saw 46A:

Just a short ride to test, did not do the long gradual hill, just the one steep behind house. (12mm belt started skipping and almost made the top of the last steep hill)

Both VESC 4.xx running FOC fw 3.26.

at 4p i think your setup will work really well - just somewhat bulky given the weight/size.

Looks like your 60C setup has very little sag regardless of high current peaks

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As @darkkevind has posted, eBay. I purchase 50x2" pieces of 10mm at .15mm thick but they are not enough and I will use them to connect the 4-packs.

I found 10’ rolls at about $4 on eBay. Of course I’ll be waiting about 3-4 weeks to get them. That’s ok. I’ll keep going over plans and practice spot welding.

So I’ve tested the 788H with a dead cell and watching a couple of YouTube videos. Disappointing results to say the least!

Any suggestions? I had sanded the welding tips as suggested elsewhere. I’ll also clean everything with isopropyl alcohol too. But what have you found for settings on the spot welder? Amps? Pulses, etc?

Build update. The pack was finished but ran into other issues (broken switches, waiting on chargers, heatsinks, fans, ebay, amazon, etc.). Ran maiden voyage of any distance this morning. Went about 9 miles. Everything seems solid. :+1:

I started at about 76% charged as I had been doing short runs as I have been tweaking the VESC firmware. After getting into work, I am at roughly 40% still charged. That should put me solidly above the 20+ mile mark I was shooting for.

Incidentally, I was surprised when @Ackmaniac’s Android app started telling me via my earbuds that my battery had discharged to ‘x’ level. Pretty cool. :grin: