


You set the tone,riba2233 wrote:
There's no need for tone like that. I just made a few points and asked a few questions, but guess you got a bit to upset to answer them, and just started bashing.
Please don't lie, my welder wont cost 350$. And while it might be "just battery short circuit device" (LOL), what is yours, capacitor short circuit device? What do you think, which one has nicer pulse shape and more controllable pulse?
So, my point was that this is ultimate 18650 spot welding repository, and your welder is total overkill for 18650 cells. That's because you can't weld material that is too thick for 18650 cell, because you will destroy them. So, if you want to weld 18650 cells (not some thick sheet metal), your welder is too expensive, and demands labor and skills. Especially for someone who just wants to make a pack for himself.
I also didn't mention my spot welder, let alone compare it to yours, because they are whole different leagues.
So, ease up on your tone, and contribute to the topic by answering questions you have been asked. Bashing someone with lies and ad hominem is not the right way to contribute on forum. Thanks.
I just followed it!riba2233 wrote:I think it's an overkill and waste of money if you are only going to weld 18650 cells. It's 600$ (with electrodes?) and you still have to invest your time by assembling it? And it's way to powerful.
I believe the way maddin88 did it is the best way and I followed in his foot prints is to have all the cells in parallel in a straight line and then the series next to it in a + up - up scenario like this picture so you don't have to have so many small pieces. Also trying to keep any one of the small pieces from falling across the batteries creating a short with so many to install would take a lot of concentration. To each their own though,mistercrash wrote:And THAT is THAT! We all good now?How about a discussion on what is the best way to connect the cells together in series and parallel? Most batteries I see that people make themselves have strips of Nickel welded to make the parallel connections and then more strips of Nickel to make the series connections. I remember dmun brought up a different way to make those connections that takes a lot less Nickel strips and despite my ignorance on the matter, it just makes sense to me. Make the series connections with small lengths of Nickel strips and then the parallel connections on the strips with a small gauge wire soldered on. Solder heavy gauge wire on the Nickel strips for the positive and negative poles of the battery. Below I included a couple drawings of a 4S14P battery, first the all Nickel strip battery I often see and second, the way dmun suggested many times. Sorry for the bad choice of colors representing some materials.g]
You are right, second picture is better option, since on the first one there's a lot of wasted nickel. However, that single soldered copper wire in the middle of the pack is not so practical because it protrudes over the plastic brackets, so it would be better to replace is with welded thin and narrow nickel strip.mistercrash wrote: How about a discussion on what is the best way to connect the cells together in series and parallel? Most batteries I see that people make themselves have strips of Nickel welded to make the parallel connections and then more strips of Nickel to make the series connections. I remember dmun brought up a different way to make those connections that takes a lot less Nickel strips and despite my ignorance on the matter, it just makes sense to me. Make the series connections with small lengths of Nickel strips and then the parallel connections on the strips with a small gauge wire soldered on. Solder heavy gauge wire on the Nickel strips for the positive and negative poles of the battery. Below I included a couple drawings of a 4S14P battery, first the all Nickel strip battery I often see and second, the way dmun suggested many times. Sorry for the bad choice of colors representing some materials.
Look, I haven't said that you welder is not great, but it's not fair to bash on mine like that. Mine also discharges precisely controlled pulses, more controlled because battery doesn't drop voltage as capacitor does. And what do you think happens after "precisely " charging your capacitor? It gets short circuited the same way as mine does with the battery. Absolutely same principle, but difference is that battery holds voltage better. Also, I can weld with one 45 Ah batter, which weighs 11 kg, making whole system 5 kg lighter than your unit. And it's more portable since it doesn't require power outlet (you can use small battery for logic).litespeed wrote:
Unlike yours this is not a "capacitor short circuit device" mine is actually a voltage adjustable charge circuit that precisely charges 3 computer grade 1 Farad capacitors that then discharge into 2 individually precisely controlled pulses and then near instantly recharges the circuit ready to go again. This one is fan cooled, plugs into any 110 outlets and completely portable for weighing in at 40 lbs so you can easily take it to your buddies house, no disassembly required.
This is picture from sunstone page, pulse shape for capacitive discharge dual pulse welder:Yes mine has a better pulse shape and more controllable pulse. Feel free to prove me wrong.
Well, I can weld with one 45 Ah battery that costs 45$ locally (you don't have to buy the most expensive one), and even two of them are 90$ which is not much. Power supply is like few bucks, and car batteries are easy to charge, you can use really simple circuit to do that, or find used battery charger, whatever. But, in reality, most people already have battery and power supply, so it's really convenient.Also I did not lie....car batteries are 75 bux each which you recommend 2 plus the needed plug in power supply and your unit with shipping is $350 and this does not include a way to actually charge the power source of yours....just saying.
John in CR wrote:2 pages of the "ULTIMATE" and still zero "how to" other than some different cell configs. If I'm going to DIY spot weld, then I want to do a better job than a typical hand assembler in China. I want to know how to make good connections that don't go deep enough into the battery to reduce its life.
You are right, I started this because a united resource was needed. I take all into account, I will compile and make sums about the -how too's- soon with info and videos. It is going slow but solid.John in CR wrote:2 pages of the "ULTIMATE" and still zero "how to" other than some different cell configs. If I'm going to DIY spot weld, then I want to do a better job than a typical hand assembler in China. I want to know how to make good connections that don't go deep enough into the battery to reduce its life.
nice, if you spot some essential info you can post the ES tread link here, and i will link it with a title on the first post.riba2233 wrote:
There are some advices in other thread (high power cells, samsung25r/lg he2/sony vtc5), maybe should be moved.
My advice - don't used nickel thicker than 0.15, that way you are on the safe side. Then you can weld something on top of it if needed.
Just regular hobby hot glue is best since it's easier to remove a cell if needed with just a little heat. If your pack is getting hot enough to melt glue you have bigger problems to think about.....ohzee wrote:What are the suggestions for holding the cells together until I can shrink wrap the entire pack ? I was thinking I would just use hot glue with a high melting point.
I also have some pretty good double sided tape that may work just as well , but be easier to deconstruct in the event it's needed. About have everythign I need to
start building my 20s15p battery just trying to decide the best way to do it. Thanks
Sunstone engineering recommended the Glidcop.....usertogo wrote:I am curious what you experts think about using Tungsten electrodes such as used by TIG welders? Of course not cut to such a needle tip but maybe just a 90deg. tip? I figure 2.4mm diameter for example or the thickest I can find mounted to the thicker wires and not protruding more than necessary from the brass block through which they are fed. I figure tungsten has the highest melting temperature, and should keep its shape for a long time, while not being so bulky as some of the copper electrodes I have seen. The idea is to rather weld many small spots than only 2 or 4 big ones!
I am planing to build a microwave oven transformer based spot welder, But I am not going to try to squeeze one big gauge wire through its secondary position but many parallel 1.5 or 2.5 mm°2 for maybe 5 or 6 windings.
Any comments welcome!
Thanks for the link, they show a wide variety of other electrode types too, among them pure tungsten and copper/tungsten mixes. Still I am hesitating to invest in a spotwelder that will then likely sit there for month if not years till I build the next battery! Doing it all on a shoestring I will likely call my local specialized welding shop and ask them to save me a tungsten electrode from being thrown away, If that doesn't work I get a single electrode on ebay and cut it apart because they are plenty long usually, an end up spending 5-6 Euros...Sunstone engineering recommended the Glidcop.....
"Thank you for contacting Sunstone Engineering. The electrodes that we recommend using for welding nickel battery tabs is Glidcop, it is a copper/chromium mix. We have special electrodes that we sell for battery welding, part number EL125BATT. These are 1/8” shaft with a 1/16” welding surface on either end. You can find them on our website here:
http://sunstoneengineering.com/products ... lectrodes/ "
They work perfect on my welder!
The DIY slit is a cool idea. I usually buy just normal pure nickel strip, but there is the option to buy some pre-split strips like these: http://www.aliexpress.com/item/0-15-7mm ... 4.2.4YFfRPspinningmagnets wrote:This slit can be added to plain nickel strip material with a dremel tool, using a thin abrasive disk.
You should have used extra washers on cell positives, and extra insulation between parallel groups connected in series.mlt34 wrote:I'd like to submit a how-to I wrote up on building 18650 ebike packs - I took a lot of pictures along the way of one of my builds to try and make a very clear walk through: http://www.ebikeschool.com/how-to-build ... 650-cells/
Thanks for the feedback!riba2233 wrote:You should have used extra washers on cell positives, and extra insulation between parallel groups connected in series.
wow nice mlt good work.mlt34 wrote:I'd like to submit a how-to I wrote up on building 18650 ebike packs - I took a lot of pictures along the way of one of my builds to try and make a very clear walk through: http://www.ebikeschool.com/how-to-build ... 650-cells/
Couple suggestions/ideas:mlt34 wrote:I'd like to submit a how-to I wrote up on building 18650 ebike packs - I took a lot of pictures along the way of one of my builds to try and make a very clear walk through: http://www.ebikeschool.com/how-to-build ... 650-cells/
interesting! I normally add the fuse when I connect it to the bike, but putting one in before the BMS, that I never thought of! I guess you could run the wiring outside the pack for the fuse, so you can still access it but keep the whole pack shrink wrapped.meelis11 wrote:I added fuse and connector before BMS for pack I built
That's a good point. I like the idea of shorter tabs for the top. The scissors cutting the nickel sometimes gives the corner a bit of a bend. I always try to put that bend up if I can't flatten it completely, but shorter tabs would solve that too.meelis11 wrote: these strips on positive should be little-bit shorter - to avoid sharp nickel-strip corners near negative case