Converting an inverter welder into a charger (and welder)

amberwolf · Jun 6, 2018

SOmething to think about when you get it:

Does it limit current in away you can adjust, either with built in controls or with built-in circuitry you can modify?

If not, then you'll need to build a current limiter for it that can handle the voltage and current you're after.

Alan B · Jun 6, 2018

What is the duty cycle rating? They are usually not 100% so it will have to be derated for charging.

Power factor of 0.73 is not too good. That means the current on the input line will be much higher than required, so the circuit will have to be derated as well.

Welders have to limit current because they operate shorted at arc initiation.

flippy · Jun 6, 2018

as mentioned, they usually have a crappy power factor and on 110V you need to watch out for the derating factor.
also thse inverters usually have 10 or 20% duty cycle. they are really not made to run for hours on end to charge a battery.

the regulation is also utter crap because it does not need to be accurate as in a charger. i expect voltages and currents to be all over the place without some modding and then some more to prevent the thing from melting.

Alan B · Jun 7, 2018

Server power supplies are rated for good power factor and continuous load, as well as good regulation. They are very low cost due to the quantity of production. They are an excellent choice if properly used.

Low cost welders are designed for light duty cycles. You'll probably have to replace the control circuitry and write new firmware to get the control precision required for battery charging. The actual continuous power rating might be only 20% of the published welding peak power ratings. The output voltage may be too low as well.

The PFC circuitry modulates the IGBT gate drive PWM over the AC cycle to spread out the load.

amberwolf · Jun 7, 2018

It would be a fair bit simpler to use Meanwell LED PSUs (many threads discussing using htem as chargers). There's a few versions; the HLGs I use are fanless, potted, weatherproof and vibrationproof, are adjustable voltage and current with knobs under rubber caps, and can be seriesed and paralleled for more total wattage. Easily bolted to the bike or vehicle to be charged to carry around with you.

Four of the ones I have is around 25lbs and about the size of four hardback books, providing around 2400W of charging capability.

trazor · Nov 6, 2018

usertogo, had you any progress?

I'm using a similar setup: https://endless-sphere.com/forums/viewtopic.php?f=14&t=97151

eee291 · Nov 6, 2018

I would recommend something like this:

PSU (92% peak efficiency):https://www.ebay.at/itm/NEW-with-box-Original-Eaton-APR48-3G-communication-power-supply-ship-by-EXPRESS/182639205884
MODS for the PSU: https://endless-sphere.com/forums/viewtopic.php?t=66169#
Programmer: https://www.ebay.at/itm/USBASP-USBISP-AVR-Programmer-Adapter-10-Pin-Cable-USB-ATMEGA8-ATMEGA128-Arduino/142957090650?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

You can mod it to go as low as 42V (10S) and as high as ~90V (20S)

All for about 100€

trazor · Nov 23, 2018

usertogo said:
eee291 said:

I would recommend something like this:
Eaton APR48-3G Rectifier Module
...
You can mod it to go as low as 42V (10S) and as high as ~90V (20S)

Click to expand...

I think there is a bit of disinformation in it too, because its not the APR48 that can go up to 90V, but this switchmode input booster that a certain motor controller seems to have build in.

Meanwhile if we are to list altwernative high power supplies I an resume that there are people working on the following:
- Huawei R4850G2 (3000W)
- Emerson R48-3200 (3.2KW)
- RSP-3000er Serie von Meanwell.
- HP ESP120 2950W (huge and 2-3times as heavy as a Huawei)
and there are more but the availability
also varies from Region to Region

Thanks for that info. The huawei price/power looks very good. https://es.aliexpress.com/item/New-and-original-Huawei-R4850G2-rectifier-module-48V-56A-communiction-power/32818030744.html

In the meantime, i've brought a dedicated 80usd DC welder. I've taken 1500W from it without halts. I will try to charge my two e-motos at the same time to push it to the limits of the duty cycle.
As some mentioned, the efficiency is very low. I measured 75% :roll:

Remember that I'm in Uruguay and the availability of components and the customs taxes make many good options for US residents too expensive here.

trazor · Dec 2, 2018

usertogo said:
trazor said:

Thanks for that info. The huawei price/power looks very good. https://es.aliexpress.com/item/New-and-original-Huawei-R4850G2-rectifier-module-48V-56A-communiction-power/32818030744.html

In the meantime, i've brought a dedicated 80usd DC welder. I've taken 1500W from it without halts. I will try to charge my two e-motos at the same time to push it to the limits of the duty cycle.
As some mentioned, the efficiency is very low. I measured 75%
Remember that I'm in Uruguay and the availability of components and the customs taxes make many good options for US residents too expensive here.

Click to expand...

Saludos hermano en Uruguay que adventura
I looked at your project and find the approach very exciting! Also very sharable by doing the 3D printing elements! I shall comment details in your thread...
The Huawei is indeed very smart, I am posting about that in a different tread which I have updated the previous tread where a variety of supplies is listed each will point to the threads about using them...
That Huawei has received some exciting updates, but it can come preconfigured in many different ways and I have heard about a CAN box circulating in Hong Kong (somebody hacked it there) (a company specializing in Huawei Power) To talk Huawei into open sourcing their protocol - Good luck !

But now on topic can you report more about the mods and specs of your inverter welder charger brother?

Hola hola! I've updated my thread on welders: https://endless-sphere.com/forums/viewtopic.php?f=14&t=97151&p=1428934#p1428934

Converting an inverter welder into a charger (and welder)

amberwolf

Administrator

Alan B

100 GW

flippy

1 MW

Alan B

100 GW

amberwolf

Administrator

trazor

100 W

eee291

100 kW

trazor

100 W

trazor

100 W

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