question

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Can I use 24 volt solar panels to charge 12 volt batteries through MPPT Controller

I’m trying to spec a system using all Victron kit and looking at the 100/30 MPPT charge controller. Does that controller accept 24 volts from solar panels and charge 12 volt batteries?


thanks

MPPT - Solar Charge ControllerSolar Panel
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2 Answers
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wkirby answered ·

Yes it does. It can accept up to a maximum of 100V in solar to charge 12V batteries.
To charge 12V batteries it needs Vbat (12V) + 5V to begin charging and the solar must be Vbat +1V to keep charging. Those solar panels Voc are probably more than 24V so you should be fine!

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Kirby, Good day to you. Thank you for your assurance.

Something that is often overlooked is that 2nd number -the "30"

That's the maximum amps out AFTER conversion by the MPPT (vs max amps input from your PV's)!

You can do some really cool stuff in small systems and places with a good MPPT controller and gear if you plan your system well! Use the calculator and those numbers above for what your mppt needs to have in voltage to start charging

A complete 24v system using 12v system wiring will be even more efficient with the bonus of no wiring upgrades necessary.

The MPPT can handle even more variety from panels and batteries as well -you just would need to set it up in the app. Your PV's will almost always have more voltage UNLESS you are using 12-18v 100w PV's (usually they run around 22v) into a 24v (28v) battery. Then you would want to series at least 2x 100w panels to your MPPT (44v for a 28v battery). You WANT your PV's to have a good amount of voltage above your bulk charging needs of your battery is the only real rule after sizing for maximum voltage you will ever see and the maximum amps the system will output from MPPT to the battery after conversion in the MPPT.

Have fun!

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avs-power answered ·

On my van I am using a 75/15 with a single Victron 24V Mono 200W panel which has a Voc of 43.2V and it works amazingly.

What panels are you thinking of running on the 100/30? As its probably best suited to a big single panel like the 305W or 360W, or two of the 200W or 215W panels, as you can run upto 440W on it (more if you want, but it will limit input power to 440W)

Some further into if you are deciding what to get... I only got a BlueSolar and added the Bluetooth dongle at a later date, but unless you need the dongle on a bit of lead to place it somewhere for a better signal... and unless its part of a more complex system... just go for the SmartSolar so it has Bluetooth built in.

If you aren't going to run more than 220W of solar just go for something smaller like the 75/15, as the other bonus is that the smaller ones have load terminals (which the 100/30 doesn't) so if you want a small simple setup, just run all your loads off the load terminals (apart from some stupidly large inverter) and you can then view the amount of power you a drawing in the app, and also has a low voltage cut off to stop you damaging the battery.

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