no.. 24v battery would goto pv input and batt to 12vHi.
It is suposed that it is the intended function of the 75/15 as long as you use the "batt" terminals for the connection.
Another question is if you use more than one single bat and each one is of diferent capacities, or even more important if each one are of different technologies, since the unit can ONLY monitor and regulate ONE of them. In case you have for instance an RV with LIPO on the rear and lead-acid for the engine, you can use the output "Load" for the lead-acid one (although I recomend the use of an aditional regulator in series for it)
Jose
The power supply was current limited. If the battery is large enough the Victron should limit at its rated current.I would expect so. Will has demonstrated many times that using a 30V/10A PS as input to a MPPT works fine.
I would expect so. Will has demonstrated many times that using a 30V/10A PS as input to a MPPT works fine.
Oops... sorry I didn´t read it all. I thought you wanted one 24 PV panel with two batteries. Sorry for the confussion.no.. 24v battery would goto pv input and batt to 12v
of course victron wouldn't recommend it... they wouldn't recommend a DIY battery either.....No, Victron do not recomend using a battery as an input source to the MPPT, it will cause damage, use DC to DC 24 to 12 charger. Victron Orion 24 12 20,
Orion-Tr Smart DC-DC Charger Isolated - Victron Energy
The Orion-Tr Smart DC-DC charger is a professional DC to DC adaptive 3-stage charger with built-in Bluetooth. For use in dual battery systems in...www.victronenergy.com
It's possible to use a current limited power supply but not a battery.
Mike
I agree this is not a practice that anyone should do, but in your experiments, was the power supply a current limited supply that could tolerate a short circuit output? I would guess/expect that as the MPPT pulled it down, our of regulation that the MPPT could do the math and see the power (volts times amps) going down and let up a bit. Did that not happen?I would not do that.
I see guys hooking up power supplies, and even batteries to MPPT ports. It may only be working as a stroke of luck. Not good practice.
I experimented with this, and some MPPTs will load a PSU down so hard the PSU will go into fault, and shut off.
The MPPT algorithm goes wild pulling the load down further, and further because it appears to the MPPT as it's milking more, and more power.
Maybe limiting the charge current in the MPPT would help, but I still don't think it's good practice.
I agree this is not a practice that anyone should do, but in your experiments, was the power supply a current limited supply that could tolerate a short circuit output? I would guess/expect that as the MPPT pulled it down, our of regulation that the MPPT could do the math and see the power (volts times amps) going down and let up a bit. Did that not happen?
I would not do that.
I see guys hooking up power supplies, and even batteries to MPPT ports. It may only be working as a stroke of luck. Not good practice.
I experimented with this, and some MPPTs will load a PSU down so hard the PSU will go into fault, and shut off.
The MPPT algorithm goes wild pulling the load down further, and further because it appears to the MPPT as it's milking more, and more power.
Maybe limiting the charge current in the MPPT would help, but I still don't think it's good practice.
A little back story. The company I work for has a IOT system that runs on solar. Basically a 20a EPEver MPPT, 200w panel, and 100ah LiFePO4
I wanted the guys in the shop to be able to maintain/charge these units before they go out to a new site. I experimented hooking up POE power supplies that have 54vdc out to the MPPT. I went through several, some were rated 2.5a, and some 5a.
They all had the same problem, it would initially work but the MPPT would pull it down, then PSU shuts off, then comes back in a cycle. Also managed to totally kill a few of the PSUs
I'm going to trust the President of MidNite Solar over you:
Testing MPP Charge controller function with bench power supply?
Anyone know if you can use a 5A-60V DC power supply to test functioning of a MPP charge controller. I have a all in one inverter with charge controller that I am testing in my shop before shipping to where it will be installed in MX. Everything is working great but don't have PV panels here and...diysolarforum.com
"We do it all the time."
Good for you!
That's likely what happens when you use undersized power supplies.
20A controller fed by power supply capable of 9-10A output @ battery voltage = poor design choice.
Even the 5A power supply can't supply enough power @ 20A/14.4V.
It should be a given that the power supply can provide more power than the output of the MPPT.
The OP wants to connect a 24 volt lithium battery to the input of a 15 amp MPPT controller, not a power supply.