12 Volt Lithium Battery Individual Cell Regulator

[MEXICOWANDERER]

This looks interesting. I wonder if they can be paralleled for larger batteries. The price is certainly reasonable.

https://www.ebay.com/itm/Lithium-Battery-Charger-Protection-Board-BMS-Li-ion-Charging-Module-3S-10A-...

[MrWizard]

if you held the button down instead of 'tapping' it

i'm sure you could over amp things

but thats NOT the right technique

but you could always use a 555 timer and a transistor or mosfet to fire the solenoid

or even use a bank of mosfets in parallel instead of the solenoid
press a button let the timer fire the circuit
get exactly the same 'weld time' every time

[MEXICOWANDERER]

If I didn't have a six foot campfire with a half dozen irons in it it might be fun. Didn't watch the video yet but I hope the battery spot welder does not over amp on discharge.

I used a GC220 one gauge cable, a connected to negative vise to solder in dish diodes and solder 2/0 Ford diesel battery cables using a quarter inch carbon electrode.

My focus presently is on getting that RSP-1500-15 battery charger finished. The Hirose connector needed 25 AWG wire and I am picking up an assortment of silicone wire and a label making machine tomorrow. Fun crossing the border Labor Day. Sheesh.

[MrWizard]

yes it can
but you are not going to weld these battery strips with that
tiny amount of power

nothing wrong, with a regulated supply for the right purpose

but welding needs Amps, lots of amps , especially for momentary contact spot welding
that weld has got to be a 100amps or more in that circuit for that split second weld, the nickel strip is basically a short circuit across the battery when the solenoid close contacts

you can built a regulated supply spot welder

but i think it will be more efficient/expedient less costly, and more timely to use the battery method

now if you plan on going into business making specialty battery packs
building the regulated power spot welder might be a benefit

sometimes quick and thrifty is the best way to go

do you really need to build a 'project' just to experiment with another project ?

[MEXICOWANDERER]

A regulated power supply can supply .1 volt and .1 ampere.

[MrWizard]

yes steel ? or maybe nickel

the DIY people don't use 60v and don't use carbon rods
they use stiff wire heavy gauge solid 'wire' electrode
contact points are side by side
its not one weld point, their systems make (2) dots on the strip
where it welds to the battery

https://www.youtube.com/watch?v=o1NFbchHeM8&ytbChannel=null

upgraded version of welder same person

(1) 12v battery , solenoid, push button monetary switch



https://www.google.com/search?q=spot+welding+18650+lithium+batteries&num=20&source=lnms&tbm=isch&sa=...

[MEXICOWANDERER]

***Detailed Info Re: Spot Welding How To?***

...and those strap conductors are spot welded .. NOT soldered to the batteries

How about this?

1/8" carbon rods held with alligator clips.

10-amp max 60 volt max power supply fully adjustable.

I am to believe that the attachment tang and the cell cap are both steel?

Place point of negative carbon rod near to where tab is to be spot welded. Push down on tab with positive carbon rod, and remove rod just after bond is made?

I can also work with a Megawatt or Meanwell at minimum voltage?

https://www.ebay.com/itm/Carbon-Electrode-Electrodes-Round-Cell-1-8th-in-x-12-in/332671946651?hash=i...

Thank you

[MrWizard]

20Ahr 12v LiFepo4 $139.99

20Ahr LiFePo4

[MrWizard]

a few links


12v 22.5 ampHr, used surplus ? $79.99
12v medical battery 22.5AmpHr
ships from virgina




12v 10AmpHr LiFePo4, new $69.99

new 10ah 12v
ships from Wisconsin

[time2roll]

theoldwizard1 wrote:
Charge/discharge characteristic are very different for Li-ion vs LiFePO4.

I thought Li-ion was more a generic name where LiFePO4 calls out a specific chemistry.
Yes the cells need to be closely controlled according to individual specs determined by the chemistry and construction.

[MEXICOWANDERER]

theoldwizard1,

Thank you. Your comment is important. The tiny size of the circuit in question lends itself (hopefully) in the right direction.

For LiFePO4 considerably more sensing, analysis and control must be utilized.

[theoldwizard1]

Charge/discharge characteristic are very different for Li-ion vs LiFePO4.

[time2roll]

I love seeing this stuff. The technology of lithium just went down in price.

[MrWizard]

should be able to parallel them

this designed to mount 'on' (3) 18650 cells
and those strap conductors are spot welded .. NOT soldered to the batteries

the DIY crowd are building their own spot welders using motorcycle size batteries
i watched some vids on youtube

the cells could end up being expensive if you buy new
if you buy used, you need a tester to find and grade the good ones from the bad ones
when building packs, you want them to have matching test/grade settings