I have a power bank made of lithium ion batterys. Its 12v and over 10 amp (I can't test it do to a lack of a tester that reads over 10 amps). I am planning on making a welder out of it using 1/16 in welding rods. But I have issues with the batteries heating up do to short circuiting them.


  1. How can I prevent them from short circuiting?

  2. what could I take a thermostat shut-off out of to make sure I don't exceed high temperatures?


I believe from what I read on the internet that I can prevent my circuit from short circuiting by doing a few things:

  1. Add a fuse to make sure that the max current doesn't flow from the positive to the negative.
  2. Add a resistor or current regulator that will prevent the max current to flow to the negative.
  3. Add a light that can handle the current to prevent it from short circuiting.

I have my two questions under the word questions. And I just added some possible solutions that I need to know if it will help prevent it. If you have any other questions I will be more than happy to edit this post.

  • \$\begingroup\$ For those of you who believe that this will not work, I have looked at the amperage ratings for many wielding rods and a 1/16 inch rod can be powered by 10-40 amp. If anyone could tell me what type of rod I should use or have any other recommendations please comment \$\endgroup\$
    – user100476
    Jul 14, 2016 at 16:02
  • \$\begingroup\$ Please make sure that you follow all safety-related procedures for welding. In particular, make sure you wear heat resistant clothing and are prepared to extinguish a fire. It is very common to accidentally start fires when welding, and also when discharging Lithium batteries at very high rates. Do not do any of these things when flammable materials are nearby. What is the total capacity of your power bank (in Watt hours or Amp hours?) \$\endgroup\$
    – mkeith
    Jul 14, 2016 at 16:05
  • \$\begingroup\$ I am not sure about the total capacity do to the lack of a high amp multimeter. I believe it was around 20amp 12 volt. Thanks for the caution I ha e welded quit a but in my life and after u get burned and arc flags a few time, you know to listen to the safety cautions \$\endgroup\$
    – user100476
    Jul 14, 2016 at 16:11
  • \$\begingroup\$ The capacity of the battery would be in Amp-hours probably. This tells you how much energy the battery contains. For example, if it really was 12V and 10 Amp-hours, you could drain it at 1 Amp for 10 hours. Because of inefficiencies, if you drain it at 10 Amps you will get much less than 1 hour. I am trying to figure out if what you want to do is remotely practical, because I know welding is an energy intensive process. I think you would need a very large battery bank to do it for more than just a few seconds. \$\endgroup\$
    – mkeith
    Jul 14, 2016 at 16:16
  • \$\begingroup\$ I believe this will not work. Even a quick Google tells me that for 1/8th inch welding rods you will need between 85 and 150A. Your Li-ion batteries will probably explode. \$\endgroup\$
    – Steve G
    Jul 14, 2016 at 16:17

1 Answer 1


If you'll take a look at page 20 of this guide by a welder manufacture you'll see that 1/8 welding rods are recommended for 16 ga material, and recommended currents run from 70 to 115 amps.

This is for a welder with current control. In your case, current will be whatever you get given your lead resistances, and may well be either higher or inadequately low.

I really don't recommend doing what you want to do. You are almost certain to blow up your batteries.

  • \$\begingroup\$ I Kent 1/16" rods, I changed it. And 1/16 run as low as 10 among depending on the type \$\endgroup\$
    – user100476
    Jul 14, 2016 at 16:37
  • \$\begingroup\$ Doesn't matter. If you can't control the current, you're going to kill the batteries. \$\endgroup\$ Jul 14, 2016 at 16:38
  • \$\begingroup\$ I will put a resistor ,fuse, current adjuster, heat sensor shut off on it to prevent it from being damaged or exploding \$\endgroup\$
    – user100476
    Jul 14, 2016 at 16:39
  • \$\begingroup\$ The parts I need to control the current to prevent it from short circuiting was the other half of my question. If u have any suggestions other then the parts I just named, please comment \$\endgroup\$
    – user100476
    Jul 14, 2016 at 16:41
  • \$\begingroup\$ A "real" welder is often AC powered and uses SCR's in a constant-current mode, and is adjustable. Large marine batteries with 100Ah rating may work, but you still need a current regulator. A resistor would be a very expensive 10KW type. You cannot do what you want to do the way you planned it. \$\endgroup\$
    – user105652
    Jul 14, 2016 at 17:17

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