How to modify a switching power supply that has voltage/current adjustable but powering it from a battery pack

[sam_sam_sam]

I have been pondering this question for a while but now I have see if this doable but I need to answer this question once and for all

I would like to know how to safely do this undertaking my first thought is to solder wires to the main filtering capacitors and see
what voltage I am getting and seeing if I can build a battery pack with voltage or not and if

I can find a BMS balancing protection board at this voltage level and weather or not do I have use more than one BMS balancing protection board

[eccerr0r]

This appears to be one of those voltage doubler input stage PSUs so likely you'll need at least 190V or so DC to get this thing started (set to 220V operation). At 160VDC or lower it will likely not work right.

[CapLeaker]

What battery pack?

[sam_sam_sam]

This appears to be one of those voltage doubler input stage PSUs so likely you'll need at least 190V or so DC to get this thing started (set to 220V operation). At 160VDC or lower it will likely not work right.

Is a 200 volt battery pack doable and if so how would you go about changing it yes a this voltage would be a little bit dangerous to play around with because the highest MPPT controller voltage I have seen so far is 160 volts is there any that go higher voltage than the ones that I have seen so far

[sam_sam_sam]

What battery pack?

This is the question that I am asking is it doable or not and feasible or not is another question

[eccerr0r]

Hooray it's one of those TL494 designs... i.e. old slower design, I'm surprised it would stay stable at 1V looking at the parts here...

[eccerr0r]

Is a 200 volt battery pack doable and if so how would you go about changing it yes a this voltage would be a little bit dangerous to play around with because the highest MPPT controller voltage I have seen so far is 160 volts is there any that go higher voltage than the ones that I have seen so far

You'll have to build your own BMS as probably most BMS won't handle such high voltages. And I don't understand how you're integrating mppt into this, this is completely different, you have to get a fairly stable power input and not depend on sunlight.

Another way to help make things easier is to design your own APFC and get rid of the input stage.

[sam_sam_sam]

Hooray it's one of those TL494 designs... i.e. old slower design, I'm surprised it would stay stable at 1V looking at the parts here...

Surprising enough it is very stable for charging battery packs this the reason for posing this question like I have

I know when I was screw-ing around with computers switching power supplies trying to change voltage out and realizing that the this concept is not practical because you would have redesigned the hole circuit to be able to accomplish this and when I saw this design and it seems work decently designed yes it not perfect but it does the job that it was designed to do which is to voltage and current and being adjustable

Now there is a version that is 0 to 15 volts or 0 to 30 volts and the 0 to 30 volts the 0 to 15 volt one supposedly can deliver 1000 watts I do not know if it is the same design or not the 0 to 30 volt one I can not remember what the wattage on this model but it is only available on AliExpress at the moment every once in while some EBay seller will have for a period of time and then they disappear for a period of time again

[sam_sam_sam]

you have to get a fairly stable power input and not depend on sunlight.

Another way to help make things easier is to design your own APFC and get rid of the input stage.

I have two questions
one how easy is it to design APFC
two I was not going to rely on sunlight but also battery power as well

I not suggesting that this feasible or not exploring possibly of doing something like this but like I mentioned earlier it might be worth it in the long run

[eccerr0r]

I don't think the transformer on that board can pass 500W or at least it seems a bit small IMHO. Then again it doesn't need to have as many windings as an ATX PSU.

And effectively building an APFC is building a wide input range boost mode 300V PSU. These can now deal with lower battery voltage input.

[CapLeaker]

The APFC idea is pretty good, but since I am lazy @$$ fux, how about a small 24VDC or 48VDC to 110 or 220VAC inverter? The effiency is down the shitter, since you converting DC to AC and then back to DC. But I am sure the AC switch for the voltage doubler circuit is there for a reason. I guess it's pick your poison. Either deal with inverter and crap efficiency, or deal with high voltage DC (I suppose you could put various battery packs in series like five 48V packs in series for 240VDC, but when you charge them you have to charge 5 packs each).

[sam_sam_sam]

The APFC idea is pretty good, but since I am lazy @$$ fux, how about a small 24VDC or 48VDC to 110 or 220VAC inverter? The effiency is down the shitter, since you converting DC to AC and then back to DC. But I am sure the AC switch for the voltage doubler circuit is there for a reason. I guess it's pick your poison. Either deal with inverter and crap efficiency, or deal with high voltage DC (I suppose you could put various battery packs in series like five 48V packs in series for 240VDC, but when you charge them you have to charge 5 packs each).

There are trade offs no matter what option you choose but question is which one is lesser of the two options evils you will give up something the real question is which one is a better option effectively wise battery charging that you can adjust the voltage and current and be the most efficient way to do I saw YouTube video on a boost converter that might be the option that I am looking for this only issue is that the lowest voltage seems to be 12 volts it might be lower but the person doing the review did go with an input voltage lower than 12 volts if I decided to try this boost converter I would have to try at lower input voltage and see how it preforms

[eccerr0r]

The APFC / boost converter is not going to be an easy solution of course. You could find a PSU with discrete APFC and just ripping off that section, though a lot of recent PSUs with APFC integrates the APFC with the switcher making it tough to separate. I'm not exactly sure how well the APFC will work with continual low voltages either, mainly because it probably still is expecting 120VDC to maintain most of the power.

Just using that inverter is much easier.

[CapLeaker]

The inverter idea is the easiest. But the best idea is straight DC for efficiency.
But I wouldn't have a use for a CC CV, High DC input voltage PSU.

[eccerr0r]

Surprising enough it is very stable for charging battery packs this the reason for posing this question like I have

You really have a 1V battery pack to charge to test stability?
I'd imagine at really low voltages it'd oscillate. Average will still be the correct voltage but will be surging up and down. Maybe so fast you need a 'scope to see it.

The inverter idea is the easiest. But the best idea is straight DC for efficiency.
But I wouldn't have a use for a CC CV, High DC input voltage PSU.

Technically a inverter that goes straight to 220V won't be too bad for efficiency. Then again it's still doing transformer -> half bridge rectifier -> filter -> H bridge -> full wave bridge rectifier -> chopper -> transformer, you could cut out a lot of that too

[CapLeaker]

Technically an inverter that goes straight to 220V won't be too bad for efficiency. Then again it's still doing transformer -> half bridge rectifier -> filter -> H bridge -> full wave bridge rectifier -> chopper -> transformer, you could cut out a lot of that too

Oh yes! All the unnecessary chit would have to be gone. Agreed!

[sam_sam_sam]

Oh yes! All the unnecessary chit would have to be gone. Agreed!

Technically a inverter that goes straight to 220V won't be too bad for efficiency. Then again it's still doing transformer -> half bridge rectifier -> filter -> H bridge -> full wave bridge rectifier -> chopper -> transformer, you could cut out a lot of that too

Could you please share a website link where I can find a decent one that I do not have to pay an arm and a leg for

[CapLeaker]

Riiight... Places like Ali and whatever is a no go for you guys at the moment due to these forking tariffs... I suggest you look for a (broken) inverter or UPS in a recycling centre and or facebook market place, Ham fleamarket etc. Or a Canadian mailing address and drive over the boarder.

[sam_sam_sam]

Is this what you are talking about

https://www.ebay.com/itm/39660749083...Bk9SR47lq-vaZQ

[CapLeaker]

Is this what you are talking about

https://www.ebay.com/itm/39660749083...Bk9SR47lq-vaZQ

Dayum. That is a cheesy and thin looking board. No protection and 150w? Looks more like 15w to me.