Spare batteries and capacitors - fun project ?

Hi, i have some spare batteries (nicd from old drill, they have low capacity, some are revived with zapping, pretty useless for drill, i also have 18650 cells from old laptop batteries) and some spare capacitors from old computer components, like power suplies.

I always wanted to have a spot welder, never needed one, dont want to pay for it, but i was wondering if i could make 1 from batteries and capacitors. Capacitors and batteries are basicly without value so i dont care about destroying them. I was wondering, how much voltage and amps would i need for it to spot weld some very tiny piece of metal ? I was thinking of putting a lot of batteries in parallel and using this high amperage OR use the batteries to charge many capacitors and just use their power.

If possible i want to do this without buying anything, basicly just from spare parts i have at home. Is this doable ?

Anyone ?

SentinelAeon said:

Hi, i have some spare batteries (nicd from old drill, they have low capacity, some are revived with zapping, pretty useless for drill, i also have 18650 cells from old laptop batteries) and some spare capacitors from old computer components, like power suplies.

I always wanted to have a spot welder, never needed one, dont want to pay for it, but i was wondering if i could make 1 from batteries and capacitors. Capacitors and batteries are basicly without value so i dont care about destroying them. I was wondering, how much voltage and amps would i need for it to spot weld some very tiny piece of metal ? I was thinking of putting a lot of batteries in parallel and using this high amperage OR use the batteries to charge many capacitors and just use their power.

If possible i want to do this without buying anything, basicly just from spare parts i have at home. Is this doable ?

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There is little that can be done with just batteries and capacitors. A spot welder is not something to be done with weak batteries (or any batteries). You have to dial in the power and duration for a spot weld (to get a bond but not melt through the sheet metal). Hard to dial it power and duration when your power is continually draining from weak batteries and capacitive discharge. The best thing you can do is put them in a ceramic pot full of sand, set them under your work bench and pretend that you are saving the batteries for a great project that you will do some day (like many other people on this site).

If you are really honest with yourself, you'll just drop them off at a lithium battery recycling center and think about a project you want to build instead of a project that can use lithium batteries (and a project you understand will not perform well because the batteries are beyond their useful life).

gophert said:

. . . . A spot welder is not something to be done with weak batteries (or any batteries). . . . .

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Well - someone have actually tried this:

Looks like that guy has way too much free time on his hands.

Ok i will forget about battery/capacity welder. Any other fun projects i can make ? I already decided i will convert my old nicd drill into lithium, and i am improving/building my bluetooth speaker. Its fun when you have so many batteries for free, its like i can power anything i want )

What kind of nicad drill do you have?

Its a 14.4V nicd drill from toolson. Its nothing special but what i really love about it is that it has a clutch that can switch between 2 speeds. Lower speed is good for screws and is 0 - 350rpm. Higher speed is for sanding/drilling and is 0 - 1100 rpm. I really like it, it says tolson PRO-AS 14.4V from, bauhaus. It has 2 battery packs and a very fast charger, also detects to high temperature. I rebuilt batteries and they work ok, but problem is after 3 days they are completely empty if left alone. Charger is very fast but still sometimes i need it right away for a few screws and would like batteries to hold charge for few weeks at least. I decided i will gather all batteries, about 30 of them and pick 10 best to make 1 nicd battery pack that will hold charge for weeks. And another battery pack i will convert to liion. I will use 4S3P pack for it, 12 battteries together and since 3 parallel each battery from laptop will only need to suply on average 3A with occasional peak over 3A. And 4 in series will give me 16.8V when fully charged. Since nicd when new were about 16V (10 batteries) i think drill should hold, i read that this drill motors are very resistant to higher voltage so 16V vs 16.8V i hope wont give me problems. I already ordered 4S charger and BMS, i will also install temperature protection to make sure it shuts down when temperature is over 50C or soo.

Interesting. Good luck.

I was wondering if I can rebuild this?

It looks like reg 18650 batteries.

But how would I bread those welds?

I just used plyers, tear it away. Then i sand both sides of bettery well and then solder normaly. Have to be careful though, dont want to heat the batteries to much.

Thanks.

fixit7 said:

Thanks.

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Yes, just 'roll' them off with pliers, manual sanding is a pain, use a Dremel with a small sanding drum, takes seconds

We also have a small spot welder, so weld new batteries together to make new packs.

I am still wondering what fun project to do with all the capacitors and batteries ^_^

Not much Fun with just using Capacitors and Batteries.

SentinelAeon said:

I am still wondering what fun project to do with all the capacitors and batteries ^_^

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Let us know when you think of something we'd be glad to help

Well i still dont understand why i couldnt do a welder. I am not planning on using it for welding batteries together, i know that it wont work well enough. But i think at least i could weld some tabs together just for fun. Shouldnt it work if i put together enough capacitors ? Maybe at least for 1 nice weld ?

SentinelAeon said:

Well i still dont understand why i couldnt do a welder. I am not planning on using it for welding batteries together, i know that it wont work well enough. But i think at least i could weld some tabs together just for fun. Shouldnt it work if i put together enough capacitors ? Maybe at least for 1 nice weld ?

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Then build one. If you go into it with low expectations, and ou really want to try it, so it. I was 9nly saying you shouldn't expect it to work well every time because voltage (and power) will keep changing as the caps decrease and your batteries will to charge or last a consistent amount of time. Good luck. Most important, have fun and be safe.

SentinelAeon said:

Well i still dont understand why i couldnt do a welder. I am not planning on using it for welding batteries together, i know that it wont work well enough. But i think at least i could weld some tabs together just for fun. Shouldnt it work if i put together enough capacitors ? Maybe at least for 1 nice weld ?

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Maybe you will waste time and end frustrated. Tabs as you think are welded with small but more predictable welders.