diy solar

diy solar

Victron 150/70 Recommended Volatage?

tmckenna

New Member
Joined
Jul 8, 2020
Messages
128
So I've been shopping for a Charge Controller for a little while now. I'd like to end up with all Victron components so that I can use the GX Touch Display. Now I was planning on doing the 150/70 VE.Can Charge Controller but some of the wording on the webpage threw me off. It says "The MPPT VE.Can SmartSolar charger connects to a PV array of 150 or 250 Volt Voc and will automatically detect and charge your 12, 24, or 48V battery bank with current ranging from 70 to 100A depending on the model." Does this mean that the array has to be configured to 150V or is it a maximum value. I currently only have some portable (300w) 12v (14.4V) panels and was hoping to configure them in series for better efficiency. Obviously that would only be about 28V so it wouldn't be anywhere near the 150V but eventually I would be using the controller in my camper with many more panels permanently mounted to the roof.
 
You can hook them up in series as long as you don't hit 150 volts open circuit.
You'll max out at 70A charge current, which works out to nearly 1 kilowatt in a 12V system.
 
You can hook them up in series as long as you don't hit 150 volts open circuit.
You'll max out at 70A charge current, which works out to nearly 1 kilowatt in a 12V system.
Ah so the 150 is in fact a max value and not a "recommended" value, and the second amp number refers to the output of the battery not input into the controller?
 
Ah so the 150 is in fact a max value and not a "recommended" value
Yeah - if you go over that voltage, you risk frying the charge controller.
and the second amp number refers to the output of the battery not input into the controller?
Right!
1623357314738.png
A handy cheat sheet - that expensive controller makes a lot more sense when you run 24V or 48V batteries ?
 
Yeah - if you go over that voltage, you risk frying the charge controller.

Right!
View attachment 52335
A handy cheat sheet - that expensive controller makes a lot more sense when you run 24V or 48V batteries ?
yeh unfortunately my camper is already configured with 12v. Might just bite the bullet to get a 100A controller and try to max it out.
 
Yeah - if you go over that voltage, you risk frying the charge controller.

Right!
View attachment 52335
A handy cheat sheet - that expensive controller makes a lot more sense when you run 24V or 48V batteries ?
Is there a way that I could have the batteries configured in 24V to make better use of the solar configuration but output 12v to the camper?
 
Is there a way that I could have the batteries configured in 24V to make better use of the solar configuration but output 12v to the camper?
There are ways, but they're not cheap.

It's always worth considering moving to 24V for the whole camper, or at least anything that requires significant power, but that really depends on how big the camper is, and the intended use.
 
There are ways, but they're not cheap.

It's always worth considering moving to 24V for the whole camper, or at least anything that requires significant power, but that really depends on how big the camper is, and the intended use.
what do you consider not cheap? I'm willing to spend a decent amount on the setup. The camper is 27 feet long, 3 queen size beds, so sleeps 6 comfortably and I'm planning on having it basically forever.
 
and the second amp number refers to the output of the battery not input into the controller?
The second number is the max output to the battery from the controller. If your panel setup and the current temperature could allow for more amps, the controller will effectively throw away the extra amps. With a 150/70 you will never get out more than 70A. In my setup, based on the STC numbers of the panels and the coldest conditions I expect to encounter in my travels, ideally my panels could generate up to 47A. I went with a 150/45 controller knowing I'll never see the ideal conditions so I'm not worried about potentially losing a couple of amps a few days a year.

You might want to play with Victron's MPPT calculator (https://www.victronenergy.com/mppt-calculator). You can enter the custom details of your panels (Voc, Imp, etc.) and it will recommend the best size controller taking into account your planned temperature ranges.
 
So I'm considering doing a non Victron charge controller initially to just kind of test the waters and figure some stuff out. I imagine the best configuration, if I wanted to have my solar panels on the roof of my camper and considering I'm using a 12v, would be connect the panels in series and keep the controller as close as possible to the battery so I dont have to run overly large power wire from the controller to the battery?
 
what do you consider not cheap?
Rewire the entire camper for 24V or 48V.
So I'm considering doing a non Victron charge controller initially to just kind of test the waters and figure some stuff out.
Buy cheap, buy twice, I can't recommend doing this.
I imagine the best configuration, if I wanted to have my solar panels on the roof of my camper and considering I'm using a 12v, would be connect the panels in series and keep the controller as close as possible to the battery so I dont have to run overly large power wire from the controller to the battery?
You always want to avoid running long low-voltage wire runs, so do mount the SCC (solar charge controller) as close to the battery as is practical. Be mindful that the SCC puts out a bit of heat during operation.
 
Rewire the entire camper for 24V or 48V.

Buy cheap, buy twice, I can't recommend doing this.

You always want to avoid running long low-voltage wire runs, so do mount the SCC (solar charge controller) as close to the battery as is practical. Be mindful that the SCC puts out a bit of heat during operation.
I'm going to have a second much smaller solar setup so the non Victron controller will still serve a purpose, and will be substantially overkill for said configuration.
 
Buy a 75/15 then, they can still do 200W into 12V :cool:
I'm reading up on "The MEG" build and hes running a 100A, 48V to 12V DC Converter. Would you not recommend I do something similar to make better use of a solar charge controller?
 
Back
Top