I am looking for an adjustable output voltage MPPT solar charge controller. I have LFP power packs that have a rated voltage of 41.6 volts (13 cells at 3.2V). I need an MPPT solar charge controller capable of handling an input from my two 400W solar panels in parallel Pmpp 400W, Isc 11.14A, Voc 45.30V, Impp 10.77A, Vmpp 37.13V, Vsys 1000V with an output charge voltage capable of being set to 46.8V. Can any MPPT solar charge controller on the market fit my needs? When I asked AI this question it pointed to the MPPT controllers Victron SmartSolar MPPT. The power packs are all in parallel. I am new to this so be kind.
You will need to rewire your modules in series to use a Victron MPPT charge controller. The minimum start voltage from the modules needs to be 5V greater than the battery voltage.
The 3.2V seems to be a fairly low voltage, most LiFePO4 run from 2.5V/cell flat to 3.65V/cell at 100%. 3.55/cell which is a good nominal for max V, gives you 46.15V, which all but the smallest MPPT’s can cope with. 13 cells is an odd number, most packs use 15 or 16 cells in series.
800W @ 46V gives ~17A, so the SmartSolar MPPT 100/20 (up to 48V) would suit this requirement.
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The 100/20 MPPT is what you want. It does charge 36V batteries with a firmware update. It will have a 36V profile for 12S, 3.65V cells, 43.8V max charge 38.4V nominal at 3.2V. You should be able to adjust the voltage for your battery. At 3.2V, yours might be LTO chemistry. You will also have to series connect the panels. They are not voltage matched and the charger will not start unless you are +5V above the battery voltage.
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7-7-2025 Victron energy chat.pdf (381.8 KB)
Take a look at the attached which shows a picture of my system an a little more about what I am trying to d. I have six 400W 48V panels in my backyard.
I just need something to charge the power packs because the 400W maximum input is each head unit is just not enough.
I am going to attach the power pack manual so you can see what I have. I think the manual and the picture in my PDF will give you a good idea of what I have.
Power Pack +1000 EN.pdf (2.3 MB)
I tried to attach the head manual, but it would not let me.
Thanks, Genmann
Genmann
Zero E head EN.pdf (4.6 MB)
Here is the manual for the head unit.
Genmann
The 100/20 will work. The input you want to use is rated for 20A. If you set it to 36V and adjust the voltages for a 13S to match the battery. Here you can see the demo for the Victron app.
You will have to series connect the panels Voc 45.30V, Vmpp 37.13V. You will need 41.6V + 5V to start charging, so 45.3V is too low. If you series connect them, you will get just over 90V and 74.26Vpp. That will give you about 800W in 74.26V x 10.7A.
Owen, I think I am starting to understand what your talking about. What do you mean when you say: Adjust to voltages for a 13S to match the battery? I can connect two panels in series. Can you give me the complete description of the Victron 100/20 your recommending?
Is there some type of wiring diagram for two panels connected in series connected to the Victron 100/20 your recommending? I see some listed as Smart solar controllers and some not, can you explain the difference?
I am excited that there is a product that will work! Now I just need to better understand how it is all wired and how it works with my power packs.
Genmann
You have a 13S battery. The standard 36V is 12S, so you have a higher voltage. Download the Victron Connect app, and you can see what settings you can put in using demo mode, like I have.
There really are no diagrams. I have done this sketch. The voltage needs to be below 100V when you connect the panels. The smart has Bluetooth built in; this is the one you want.
