I've been searching far and wide for a good demonstration on using the cheap PWM solar controller, and finally I found this video. Thanks so much for the thorough demonstration. Your work here is very appreciated. As requested, I will follow your channel. Thanks so much...
@DCGUY7 күн бұрын
Thanks for watching and your support, it's appreciated
@maxtorque22773 ай бұрын
Also to add, i've just seen in your tests your PSU supply voltage (14v) is only just above that of the battery (13.4v) for the PWM controller and yet you wound the PSU up to 28v for the MPPT!!! In the first case, then you haven't even got a PWM converter, you've got a switch and a switch that is basiclly just ON all the time because basically outputV = inputV. Repeat you test with a realistic PV voltage as used for the MPPT test, typically twice your battery voltage, perhaps 3x, and you'll see a very different result as suddenly the switching losses are going to show as well as the resisitve ones, because the unit is actually going to have to voltage match (step down), and reduce it's PWM duty cycle. Worst case will be at 50% duty cycle, (PV = 2 x battery) where the current ripple is greatest and hence I^2r losses increase (losses go up with current ripple, even if the RMS value is identical) Which is where you tested the MPPT controller!
@DCGUY3 ай бұрын
I made no changes to the power supply unit, the PWM and the MPPT simply handled the incoming voltage differently. The PWM throttled the incoming Voltage, whereas the MPPT accepted higher Voltage. I accept what your saying about actual solar voltage will show the MPPT is more efficient at harvesting solar over a PWM.
@maxtorque22773 ай бұрын
@@DCGUY You might not have made a change but the power supply impedance was very different and as a results your efficinecy measurements are not directly comparable! For efficiency tests you PSU must be in "constant voltage" mode, and able to supply sufficient current during the test so as to not enter current limiting mode.. if the PSU enters CC mode (current control) then it is, in effect, doing the job the DUT (Device Under Test) should actually be doing, and as you are measuring post PSU, then clearly that PSU is carrying some of the losses instead of the DUT!. You also need to be careful to ensure you measure voltages directly at the DUT, using Kelvin voltage measurement techniques (ie seperate voltage measurement wires that carry effectively no current and hence experience no voltage drop). These might seem like minor points but they are CRITICAL if you want to accurately and fairly measure the relative performance of such devices. In fact, because typical RDSon for the sort of mosfet arrays used is less than 100mOhm, your test wiring will actually a similar level of loss to the system as the DUT itself (which is why your recorded efficiencys are so low)
@maxtorque22773 ай бұрын
@@DCGUY Please note that POWER OUT = (POWER IN minus LOSS) and that the power is just volts x amps, and resistive losses are the square of current, so you can see that the largest effect on transfer efficiency is the voltage ratio over which that conversion is effected!
@DCGUY3 ай бұрын
@@maxtorque2277 Thank you for sharing you knowledge and experience with us, this is how we all learn. As far as I thought the PSU would simply output the same current regardless of the DAT and I put the low volts going into the PWM as internal resistance of the mosfets / circuitry pushing up the Amps. I'm going to be doing further tests with the 50A PWM when it arrives and will take all your advice on board. Really do appreciate you taking time to comment and help others, every day is a school day! , cheers 🍻
@maxtorque22773 ай бұрын
@@DCGUY PSUs can run in either Control Voltage (CV) mode or Control Current (CC) mode depending on the settings, er, set! However,in either case, when the output power hits the PSUs maximum limit, it MUST always drop into CC mode and reduce output voltage to protect itself. Hence, 1) with a High Output impedance ( low output load) the output voltage can be set by the CV knob, and will track up and down following that control setting, as long as the Current limit is set high enough so as to not become limiting 2) Low ouput impedance (high load) you will find that withing the power envelope of the PSU it will follow the "Higher" of the Current and Voltage setpoints, ie it will increase the voltage up to either the point the voltage limit control is reached OR the point where that increased output voltage pushes enough current through the load so as to reach the Current control limit For your tests, you will have to find a suitable setting that stays within the Voltage, current and Power capability of your PSU As Power output from a PV controller is Output Voltage x Output current, the easiest way to limit total power is to simply keep the ouput votlage low. For example, at the 15amp output current limit of the Victron MPPT, 10v is 150 watts (10x15) and 20V is 300W (20 x 15). The victron MPPT actually has quite a nice feature in that it can start even with an output voltage of zero volts, in no battery connected. Ideally a DC load that has a selectable drop out voltage, ie a voltage below which no current is drawn, would be used, and the drop out voltage set appropriately to limit the maximum power required during the test
@jeremyjedynak10 күн бұрын
Thank you for doing these experiments, and also for showing that a DC PSU can be connected to the solar input side to simulate solar panels!
@stevenbliss9893 ай бұрын
Actually apart from the non VI conversion the PWM is much more efficient, which is why PWM is better for small battery/panels setups (unless your panels are far above the battery voltage).
@Fester_3 ай бұрын
Good job. Quality info given and the PSU you use is a great price using the link provided. I have V.100/20 sitting next to my new Phoenix 48/1200 . Not the perfect buy but I wanted/needed another inverter in a hurry. Better to have something right away, power can go out so so quickly. Thanks for the upload, keep at it, keep improving.
@DCGUY3 ай бұрын
Thanks for watching and taking time to comment, it is appreciated and yes it's wise to be prepared for power cuts.
@junkerzn73123 ай бұрын
You'll be surprised at how versatile the 100/20 is. The next step up from there (for 48V) is the 150/35. The 100/20's are great though, I use tons of them because they are so small and useful. ~20A x ~54V = greater than 1000W of solar going into one little unit. Hard to beat that. You can also use the Victron charge controllers to down-buffer to lower-voltage batteries. I like them better than the Victron DC-to-DCs. So 48V main system voltage but you still have some 12V gear, or even some 12V "emergency" gear like a radio (say on a boat). You run the 48V through a fuse to the "solar" input of a victron 75/15 and the output to a 12V battery and, bang, just like that you have satellite (localized) emegency backup on top of the 48V emergency backup. Plus the 12V gear can deal with high surge loads since there's a 12V (well, 12.8V LiFePO4) battery in the mix. (fuse is mandatory just in case Victron's solar clamp feature ever activates, which it won't under normal operation. But still... fuse mandatory on "solar" side for that use case). -Matt
@rorymax82333 ай бұрын
Yes, I learned a few new things here, thank you.
@DCGUY3 ай бұрын
Thank you for watching and taking time to comment its appreciated
@johnshaw3593 ай бұрын
Essentially, MPPT prevents voltage collapse of the panel when power/current is taken from it. As seen by the voltage at the maximum PowerPoint - Vmp, and this varies with the PV type used and its environment.
@DCGUY3 ай бұрын
Appreciate you taking time to watch and comment, thank you
@jasonbroom71473 ай бұрын
Very good video, with a surprisingly deep dive into the settings and options of each controller. For most folks, the increased output of the MPPT, particularly during partially shaded conditions, makes this discussion largely academic. Also, I think you'll find a lot of people are opting for lithium iron-phosphate batteries and advanced communication throughout a comprehensive system of components. PWM contollers still work quite well for a more simple, and some would argue, more reliable solution. From a cost/value perspective, I think you're really further ahead to go with an MPPT controller, higher voltages, and the much better LFP batteries.
@DCGUY3 ай бұрын
Thank you for taking time to watch and comment, it is appreciated.
@user-vk5ws3jl1l2 ай бұрын
Thank you for the demonstration and explanation, very useful.
@DCGUY2 ай бұрын
Thank you for watching and taking time to comment, it is appreciated.
@user-vk5ws3jl1l2 ай бұрын
@@DCGUY i have seen people using a buck dc to dc converter to pull energy from the car battery for their portable power station. They can pull say 500 watts when the engine runs and feed it to the solar entry of the station. I wonder if load output on the mppt charge controller could be used for that..🤔 So in a 24v configuration the load output would be double the watts you demonstrated. Do you have any idea.?
@user-vk5ws3jl1l2 ай бұрын
I just tries this and got 240w input from the load output of mppt into my oukitel portable power station. But it jumps to 0 after a few secs and starts back again after a while. Maybe bc solar was not connected..
@DCGUY2 ай бұрын
@user-vk5ws3jl1l The mppt controller won't be able to handle initial surges and you are also limited to how many amps the unit can handle on the dc output. Some are as low as 1A in a 48V setup.
@user-vk5ws3jl1l2 ай бұрын
@@DCGUY Thnx, i tried connecting it in serie with solar into oukitel but still got same problem. Ill add a dc to dc buck converter for stable 500w input.
@niemma23 ай бұрын
Briefly explained, PWM controller is just regulator, MPPT is conventer and it can utilize higher panel voltages for current.. I have EPEver 20A controller, panel 360W and sunny day panel gives 30 ish Volts what gives roughly 10A , output current from controller is roughly double when my system is 12V and max charge set to 14.2V for Lifepo4 battery. Sorry my bad English im from Finland.
@DCGUY3 ай бұрын
Appreciate you watching and taking time to comment, thanks
@junkerzn73123 ай бұрын
A Victron 100/15 ? That's really quite ancient, haven't seen one of those in a long time. The Victron 75/15 and 100/20 are more current. In anycase, the 75/15 and 100/15 can only handle up to 24V batteries (roughly 30-some-odd volts) on the output. The 100/20 is the go-to for 48V batteries. In anycase, there are some other likely serious differences, particularly when it comes to protection circuitry. Most no-name charge controllers are not current-limited devices (means you can over-current the input and burn it up), and also do not have real voltage protection circuitry. The Victron's have full current limiting and control (output current limit can be set in the app). The Victron's also have automatic temperature power derating above 40C ambient (60C on the heat sink, roughly) so it's fairly difficult to blow one up. Not impossible, but difficult. And the Victron has multiple over-voltage protection circuits, including a clamp on the solar input if all-else fails. The Victron is also nearly fully-potted and full of sand to help sink the heat while that little PWM controller probably isn't. And the Victron has much, much better bulk/float handling (its night and day really), particularly as the battery gets full. So some fairly huge differences, actually, above and beyond PWM vs MPPT (DC-DC buck) operation. The temperature compensation on the Victron monitors an external device, such as the temperature sensor connected to a Victron shunt. It won't compensate based on its internal temperature readings since those have nothing to do with the battery, and you can't connect a temperature sensor directly to the charge controller. You need a separate device that is smart-networked or VE.networked in. -- In terms of the "diverting the current"... no, the Victron isn't diverting anything. The "load" output is just a FET switch off of the battery. It is NOT regulated in any way. The load will take current from both sources if it needs to, but its just relative voltage. If the load is less than what the charge controller is outputting, most of the energy will come from the charge controller because the voltage draw-down won't be sufficient to pull from the battery. If the load is greater than the charge controller's output, then the battery will make up the difference. Since the current draw is entirely related to the voltage draw down, and the battery has a different effective internal resistance at different currents, you do get decent current sharing between the two depending on the state of the battery. It won't generally be all one or all the other. -- If you have a full-time DC load and do not need fine ON/OFF control (i.e. depending on the battery's low-voltage disconnect), just connect your load directly to the battery or use the LOAD output of the Victron to articulate a relay. Finally, note that the LOAD output on the low-end Victrons can only handle resistive loads. They can't handle inductive loads or even devices with input capacitors, at least not very well... they are very, very sensitive to short conditions and will turn off. The LOAD output is also pretty easy to burn-out... a failing off these smaller Victron's. The larger Victron's don't have LOAD outputs at all because they realized that they couldn't just use a cheap FET as a solid-state switch without a bit more protection and control circuitry. In anycase, nobody in this day and age should be using PWM charge controllers. The Victron's are pretty cheap and offer an almost unbeatable set of features. -Matt
@DCGUY3 ай бұрын
Awesome information, thanks for your input.
@VinoVeritas_3 ай бұрын
Maximum Power Point Tracking Pulse Width Modulation
@DCGUY3 ай бұрын
That's what I said, only in Scottish 🤣🤣🤣
@michaelfitzpatrick36413 ай бұрын
Interesting, but not a test of solar performance. Repeat the test using solar panels and you will find the MPPT, (maximum power point), controller is able to convert much more panel power than the PWM, into useful battery and load power. The load outputs, other than for controlling lights, say street lights, are rarely used for most applications. Usually loads are connected directly to the battery. What was not investigated is the actual charge process . A PWM controller will have a badly configured charge profile, typically overcharging the battery and reducing battery life. The Victron MPPT, with preset charge profiles for all battery types, will correctly charge the battery. In addition the Victron controller has detailed information on the charge process and battery condition. You also get a 5 year warranty.
@DCGUY3 ай бұрын
Absolutely, it wasn't a test on solar performance and MPPT are way more efficient at gathering solar energy over a PWM. Appreciate you watching and taking time to comment, many thanks
@marting62133 ай бұрын
I would be more interested in a test with solar connection to see what the differences in the 2 units
@DCGUY3 ай бұрын
Yes, that's on the cards.
@fredrikbergquist57343 ай бұрын
If you have a 100W solar panel that outputs 20V mppt is not going to make much difference, just marginally at dawn and dusk. But is you have a 320W 40V panel you must have a mppt controller. Several 100W panels can be connected in parallell to increase the charging of the pwm.
@DCGUY3 ай бұрын
Thank you for watching and taking time to comment, it is really appreciated
@user-es8ed3xu7k11 күн бұрын
I have just bought the same PWM controller as a kit with one 30W solar panel.I plan to install it in a small sail boat with two flooded lead acid batteries. The idea is to use them to Keep the batteries charged . I have 2 flooded lead acid batteries. I will not be adding any load from anything to the controller unit . Should I be concerned about battery temp in this situation? As In your video I think you said something about Temp compensation and this unit does not have the temp compensation function. with lead acid Batteries? I live in the west of Scotland .
@DCGUY11 күн бұрын
Hi, no I wouldn't be too bothered personally as any affect will be negligible.
@user-es8ed3xu7k11 күн бұрын
@@DCGUY Thanks for the reply .
@craigsmith84952 ай бұрын
hi dc guy on the pwm controller, am i right in thinking that i can use the load side of the controller to connect that straight onto my vehicle starter battery to also keep that charged up as well by solar, as charging my leisure battery in my van all at the same time , as im new to all this so i hope that made sence buddy , cheers in advance craig ps im also a subscriber 😀😀👍👍
@DCGUY2 ай бұрын
Hi, I understand your thinking. The power from the load output is actually coming from the main battery you have connected and as such any loads are powered in this way. It would be simpler and safer to connect your other battery in parallel with the 1st battery (positive to positive, negative to negative to keep voltage the same e.g 12V) This way you benefit from the charging protections, using load would bypass any of these protections. Hope this makes sense. Cheers 🍻
@JouniKyyronen-nv1ep17 күн бұрын
@@DCGUY dcdc relay so not drain battery, but some took power from cigarette lighter and used it as solar power, is it too low voltage to charge second battery 14,...v
@pchris6662Ай бұрын
Didn’t you say that controller only supports flooded, tell and agm batteries? That looks like a LiFePO
@DCGUYАй бұрын
The pwm isn't configured for lifepo4 charging, although many use B3 setting which is the FLA setting
@irepairofpc31familykartrac513 күн бұрын
I have a 60 amp cheapo PWM like that. I charge 2 AGM and 2 lifepo4 batteries off of 600 watt solar and run my a/c in my work trailer 8 hours a day never had an issue yet. I make sure to use bigger wire than recommended though just to be a little safer.
@lylestavast76523 ай бұрын
what's the best type controller and setup for 2 solar panels mounted on a vehicle that will be in near constant motion and can't be sure it'll be in full-panel sun conditions - eg partial shading might happen. is this something a buck/boost charger is used for and are there any available that would fit where one of these common MPPT type would be used otherwise ?
@DCGUY3 ай бұрын
It depends on the wattage of your solar panels, their VOC (current under no load), the type of battery or batteries your using as well as their voltages. MPPT Controllers can handle higher voltage systems where panels are wired in series and are more efficient. PWM are used for flooded or gel type batteries. Panels in series, if one panel gets any shading it affects both panels output, whereas a parallel set up won't be as badly affected as long as one panel gets sun. Once you know your voltages you can choose a controller to suit input range. Https://dcguy.co.uk may be of some help
@mariovalgamidadez99343 күн бұрын
Whats the current on the usb ports
@DCGUY3 күн бұрын
5V (2.5A maximum)
@mariovalgamidadez99343 күн бұрын
@@DCGUY why am i getting only half?
@DCGUYКүн бұрын
The current is split between the USB ports, so 2.5V
@richardbrown6927Ай бұрын
Sir can you give me a call?!
@maxtorque22773 ай бұрын
"efficiency" in terms of power transfer losses is ABSOLUTELY not the same in a real systems as "solar energy harvesting performance" Both these units are using a pulse width modulated (switching) DC DC converter, of a BUCK (voltage reduction) architecture, and both will be using very similar components (N channel mofset(s) and wire wound inductor) to achieve that, and as a result, it's clear their power transfer efficiency, when measured statically is going to be very similar! In fact, the unit with the greatest PV input voltage (Victron 100Vdc, cheap unit, 50V) WILL be the less efficient one, because RDSon (the resistance of a mosfet when it is turned on) is higher for a mosfet with a greater Vds (the max voltage it can switch)., so its resistive losses will be greater unless additional effort (and cost) is expended to reduce that resistance (greater number of power switches or better switch performance ie a "better" mosfet So, in your static test, with a steady input voltage, and an effectively fixed output voltage, it's no surprise the units perform similarly. However, in practice there are two rather important effects that will absolutely make the Victron MPPT unit massively outperform the basic PWM; 1) The resistance of a mofset increases as it gets hotter. Look at the thermal design of the victron unit vs the cheaper unit. No contest here, the Victron unit is going to maintain stay a lot cooler and hence, in practise and especially at high PV insolation when output current will be high, the Victron unit is going to deliver a higher efficiency. In fact, dissassmbling the pwm unit and looking at the thermal paths, this unit is going to be terrible for use at anywhere a sustained output near it's theoretical rating 2) A real PV panel or array of panels is absolutely of a complex impedance. The ability of any MPPT controller to dynamically impedance match the PV to the load across a wide range of insolation values and panel temperatures and states (including aging) is, in a real system, running for years in order to get a ROI, going to make an enourmous difference to its harvesting performance!
@DCGUY3 ай бұрын
Really appreciate your input. Thanks for everything
@chimpspecialist2 ай бұрын
The $10 charge controller on the left is cheap for a reason.