Adjustable Boost Power Supply DC-DC Constant Voltage Current Charging Module

[sam_sam_sam]

Yeah it is dangerous, was planning on building a dual LM317 CC/CV linear charger in the meantime (~70% efficient straight from panels) though technically... I should be able to use that linear supply and bypass the transformer/diodes and have the same efficiency... HMM...

If done right it should work fine just make sure that you use a couple of heat sinks on the LM317 if you can find the T3 mount type it has better heat transfer than the 220 type just make sure that you the right wattage resistor because if you are going to use one amp output mode

[eccerr0r]

Think it would be better if I hacked the otherwise useless 24V linear PSU which uses 3 TO3 series pass transistors and a LM723. Just need to hack in a viable current limit and should be good to go. It'll be more efficient with the solar panels I'd think because it won't need to drop as many volts since the PSU transformer output is higher voltage... (The linear psu was already rated for 6A continuous so this will be better than any LM317 design I could hack up short of one that also has series pass transistors.)

however will need to redesign the psu to run totally off the solar panels, currently it uses two windings on the transformer to allow for instant on/off.

Still want to target a SMPS solution somehow. Need to get efficiency up so arbitrage is viable instead of trying to target just absorbing excess.

[sam_sam_sam]

There is an issue with the volt / current meter module the current meter is a little over one amp off in its reading results which I will probably remove it and use a different meter module after I run some more tests today if the sun will corporates will me long enough to determine if it can or cannot charge 12 volt battery packs on one solar panel

Still want to target a SMPS solution somehow. Need to get efficiency up so arbitrage is viable instead of trying to target just absorbing excess]

I would be very interested in what you come up with if you can get this to work

Also how well dose a GTI work on 220 volt without using a neutral tap for 120 volt circuits

I am having hard time understanding how you could get this to work correctly and not not have issues with this setup now a 220 volt device no issues doing this

[eccerr0r]

120V GTI works because there's an autotransformer somewhere and it could be outside your house. Same with 240V but I'd not get one for 240V w/o a ground tap. And definitely not a 220V one rated for 50Hz.

[sam_sam_sam]

Well did some testing on a 12 volt battery pack with the boost converter and results are what I expected it to be at 12 volts what ever the voltage is the battery pack voltage is very close to that and the same thing with the current is very close to the same between the solar panel and the battery pack voltage

Which is what I expected now the current did come up to 6 amps until the battery voltage was at 13.5 volts and this also what I saw with the MPPT solar panel charging controller so this part looks good so there description seems to be accurate in that does function like a MPPT charging controller to some extent now when it is in the boost mode the current is almost half of what the solar panel current is which is what you expect being in the boost mode so the results are decent

Now weather or not it can handle 100 amps input I with what has been mentioned above maybe it can but I have my doubts because they are using the enclosure as a heat sink and a cooling fan which actually does come on when the enclosure get to warm

I just not sure if the enclosure can dissipate that much heat that 100 amps input from the solar panels I do not think that I will ever get that close to what they claim it can handle

I have a concept about running one of my battery testing machines on a solar panel / battery pack setup I think it might be feasible to do it because it runs on 24 volts switching power supply and the functioning controller is running on 12 volts from a linear voltage regulator a LM7812 ic chip

I am thinking that it should work because the buck converter only controls the current output from the buck converter which is a XL4015 ic chip so I think I can use a couple of these 24 volt battery packs from BH and it should work ( I going to give some more consideration think about what could go wrong with this concept)

I am very interested in your project about doing a SMPS power supply for a solar panel charging system

[CapLeaker]

I think as higher the voltage difference is heat becomes a problem and thus limits you current output.

[sam_sam_sam]

I think as higher the voltage difference is heat becomes a problem and thus limits you current output.

I became aware of this because of the difference of input current versus the output current which would mean that the mosfets are switching harder which would increase the possibility of generating more heat

Now if you keep the voltage difference to a minimum of what is needed then you get more current output and less chance of producing more heat than necessary now I could be wrong about this assumption if I am wrong please correct me if I am wrong about my assumptions

More testing needs to be done to understand how much difference in current will produce an acceptable result and not be a danger of thermal runaway situation and destroy the entire circuit to point of no return

[CapLeaker]

I became aware of this because of the difference of input current versus the output current which would mean that the mosfets are switching harder which would increase the possibility of generating more heat

Now if you keep the voltage difference to a minimum of what is needed then you get more current output and less chance of producing more heat than necessary now I could be wrong about this assumption if I am wrong please correct me if I am wrong about my assumptions

More testing needs to be done to understand how much difference in current will produce an acceptable result and not be a danger of thermal runaway situation and destroy the entire circuit to point of no return

Nohing to correct here Sam… you are on the right path! The circuit shouldn’t be allowing thermal runaway to the point of no return. It should go into protection mode.

[sam_sam_sam]

The place where I bought two 100 watt panels 12 volt at 6 amps for $49.00 each
Now they had a 190 watt panel for $109.00 12 volt at 9 amps but a floating voltage of 24 volts instead of 20 volt on the 100 watt panels ( one note these panels are 1/2 off the original price as well )

I going to see if I charge the 24 volt battery packs from BH

Because I was not happy with the results that I got from one single 100 watt panel trying to charge a 24 volt battery pack on it I was only getting about 1/2 of the current output I would like to see around 75 to 80% of the input current because at around 5 amps output I was getting around 3.5 I want to get it closer than that

The problem is if you put two 100 watt solar panels in parallel I will have a 40 volt floating voltage I can not use it this way because the input voltage needs to be a little lower than the battery voltage is


Ideally I would like to only see an amp difference between the incoming and outgoing current or closer if possible when not near the battery cutoff voltage point because the cutoff voltage for these battery packs are around 30 volts I do not want or need that much current when the battery pack is nearly fully charged a waste of energy from the solar panels I need more current when the battery cells are at a low state of charge this is where I need the most current available

If this works better than the 100 watt panels I will buy a second one so I can charge 4 battery packs at one time

[eccerr0r]

What's the total surface area of the 100W panel?

Again I once bought a panel that was supposedly 100W but only could muster 60W. Can it get 5 amps short circuited? The panel will never supply more than Isc so it's worth testing. A proper boost circuit should easily hit close to a short circuit as it charges the inductor up with the fully-on mosfet....

[sam_sam_sam]

Here is the website link where I bought these 100 watt solar panels

https://hqsolarpower.com/hqst-100-wa...Q2OW7Wp9_HTDV7

Here is the website link where I bought a 190 watt solar panel

https://hqsolarpower.com/190-watt-12...e-solar-panel/


One note apparently this company also has a problem with responding to emails when customers have issues with one of their products something similar to the issue that you might have with Battery Hookup they both sell decent products but you are basically on your own if you have issues with any of there products this seems to the norm now with online ordering Iin general I do not understand how and why companies think that customers service is not very important anymore but this trend has become more prevalent over the years this is one more reason I am saying that corporate America is sick and needs to get there act together

[eccerr0r]

Hmm..I don't recall hqst giving bad panels, but did you try the open circuit and short circuit tests? I'd hope you'd get at least 80W from the 100W panels when not using mppt. But yeah efficiency apparently is the matter, and CS with their own bad panels is "just a small cost" that may not justify better CS or QC...

BTW looks like your 100W is a 30 cell, and likewise my 30-cell panels, a lot of hardware don't like them (and there are a lot of hardware that do...)

[sam_sam_sam]

I did some testing with this 190 watt solar panel that I bought test results as follows

9.5 short circuit
24 volts no load

With the boost converter I get 9.1 amps and when the fan kicks on the amperage is around 8.8 amps

Charging a 24 volt battery pack the
input current at 9.0 amps
input voltage 24.5 volts
input current to battery pack 3.35 amps

input current 9.0 minus output current is 2.5 to 1 ratio but this with battery only having about 25% battery life left in it as the voltage goes up the output current will go up slightly but I am not sure if this is very efficient to use with battery voltage being low in the beginning not bad when the voltage gets closer to 25 volts it will be slightly higher in current

I will have to buy another 190 watt solar panel and hook it up in series and see if the results are any better or I will just use the MPPT solar controller