Welder Operation

Status
Not open for further replies.
dereckbc

dereckbc

Moderator
Staff member
Location
Plano, TX
OK this sounds crazy I know, but here goes. I modify golf carts and EV's as a hobby. I was talking to one person who shares the same interest and he told me of using a DC welder to charge a 130 volt battery stack for a golf cart. Needless to say my eyes rolled back in my head and glazed over. :roll:

First I did not know they made DC welders, not my are of engineering. Anyway this guy told me he used a inexpensive 120 volt DC Welderr with a current regulation of 5 to 70 amps as a battery charger. Again I was stumped as to how it might even be possible.

So the wheels started spinning in my head how it could even posible work. With a 120 VAC circuit the most power he can produce is about 2000 watts before CB's trip (20-amp). In order to charge a 130 volt battery stack, you would need to supply 162 volts DC at some current limitaion. Based on say 2000 watts that current limit is around 12 or so amps. Is it even remotely possible to deliver that kind of voltage and current with a DC welder?

Can anyone tell me how a DC welder works or is there such a thing?:confused:
 
Was that 130 Volts or 13 Volts.

The Welder (DC) is impedance limited by the design of the saturatable core, and as the limit of Wattage is loaded into the system, the output Voltage drops quickly.
My experience is that the upper voltage is > 24V and it drops quickly down to the lower range of <12 Volts as the arc takes and current is drawn hard.

I need to go measure a DC welder to get some more accurate readings.
I think that if the output was upwards of 120V it would present a danger to the user.

Interesting idea, though, using a DC welder to charge a golf-cart.
 
glene77is said:
Was that 130 Volts or 13 Volts.
Click to expand...
130 volts. 65 x 2-volt batteries in series rated at 50 AH. Its a 90 MPH modified golf cart that does wheelies and boils the tires. A drag racer. for a 50 AH flooded lead acid battery the max charge current should be around 5 to 7 amps to conform to a C/10 to C/8 charge rate.

FWIW I am told it has a DC series wound 40 HP continuous/160 peak electric motor with a 500 amp PWM controller.
 
Last edited:
I don't think they use that much voltage for welding. An OSHA rule limits the maximum open circuit votlage for manual DC arc welding equipment to 100 volts. 1910.254(b)(3)(ii)(A) I would expect that the voltage under load would be much less than the open circuit voltage.
 
Could it be they are charging the batteries in parallel or 1 at a time? Some reason I was thinking a small stick welder maxes out at 60v but maybe it's a bit higher, enough to charge 1 battery or parallel? I don't think you have a very good control of the output on the bottom end 120v welders. Some, maybe most do have DC output as reversing the polarity affects the weld as needed.

I have used those cheap 120v buz boxes. Some will trip a good 20a CB if you go max and over due the next to nothing duty cycle.

Why not go with 4 or 5 of those batteries and take it out on the Salt Flats for a golf cart world speed record?

http://www.guinnessworldrecords.com/register/login.aspx
 
well I have heard of alot of ideas but that one actually sound like it would work well. the amount of amperage generated by the welder would be larger then the normal 2amp or 10amp charger purchased at the box stores. It should reduce charge times and last longer then normal chargers used on such large duty cycles as what he is subjecting it to. normal golf cart is bank of 6 deep cycle batteries and charging them is like 12 hr job. I would have to measure the voltage on lower end but would thonk that you should be able to generate 16 volts or so at around 25 ro 30 amps. but do not have any welders in the size area discribed to verify this experment. Dereck please find out more info let us know like is he using a miller or licoln welder, is it a transformer oe generator style welder. thing like that.
 
Status
Not open for further replies.
Top