Crazy Idea: combine solar + DC powersupply on PV Input of Victron MPPT Solar? (parallel? (80V) or serial?( 40V = too little to charge 48V LiFePo4)
the idea is to solar charge a eCart and at night charge with gread X-D as easy as possible
so ideally no switching between power inputs… but not sure how this should be done
also: when there are 800W (80V + 10A) on the PV Input and no battery connected, will the Victron MPPT Solar 100|20 survive?
how would u solve it?
You cant do that, use a dc to dc charger
A few things:
You can’t use a 100/30 to charge a 48vNom battery. 100/20 or 150/35 and up.
No, if you’re using solar to charge a 48vNom battery you have to either have a large panel that’s putting out high-enough voltage (70+, realistically) or multiple panels in series.
No, the battery must be connected first, and disconnected last, as per the user manual. Do not have power running into the controller without a battery connected.
No, the PV input on a solar controller is for PV, not a power supply.
ok but what would happen if someone connected a 60V DC 5A powersupply on PV input?
already tested with 48V DC power supply, the MPPT 100|20 (why so many versions?) turned on but would not charge 48V LiFePo4 because needs +5V so minimum 53V better 63V (charging voltage of the battery is 58V+5V) or more to charge
how would u solve it?
buy the recommended 150 bucks 48V charger?
(ok there are cheaper one’s but no idea if they are any good https://de.aliexpress.com/item/1005005714288018.html)
and put it in parallel to the Victron MPPT Solar? (does the Victron MPPT Solar have a problem with that?)
You’re playing with something that has the very real possibility of going into thermal runaway and taking everything in its immediate vicinity with it, up to and including you, your family, and your neighbors.
Yes, please buy the recommended charger.
OK IF U THINK LIKE THIS: DO NOT EVEN BUY ANYTHING, NO VICTRON NO NOTHING, DISCONNET YOUR HOUSE FROM THE GRID
THROW AWAY UR CELLPHONE + MOVE INTO THE MOUNTAINS
= NOT THE SOLUTION IS IT?
that is not the answer to the question: WHAT CAN GO WRONG IF PV INPUT OF A VICTRON IS POWERED BY A DC POWER SUPPLY, WHAT COULD GO WRONG?
ACTUALLY ALSO OWNING A MPPSOLAR 5k AND WILL KEEP RECOMMENDING IT 
IT CAN RUN WITHOUT A BATTERY X-D
IT ALSO SOUNDS LIKE U HAVE NO CONFIDENCE IN UR OWN PRODUCTS X-D “IT WILL DEFINATELY BLOW UP”
So, first, stop yelling. All caps isn’t helping your case.
Second, yes, improper connection of components can result in component failure, fire, property damage, up to and including injury and death.
Third, hyperbole also isn’t helping your case. Do things correctly, or not at all, for the safety of yourself and all those around you.
would have had more productive input and ideas and solutions to this problem, but will not share them because no one properly answers the questions here.
so if it’s a POWER SUPPLY that allows Voltage and Ampere REGULATION = LIMITING to a certain max value (like 60V and 5A) that the PSU can handle permanently = it SHOULD WORK X-D
otherwise MPPT Victron will try to max out the power from the DC POWER SUPPLY and maybe overload the powersupply.
So, couple of things, again:
First, please familiarize yourself with the Community Guidelines, and in this case particularly the admonishment against using AI:
Second, we’re not support staff, we’re volunteers - some experts, some installers, some distributors, and many many system owners. Product support comes from your authorized Victron Distributor.
I’ve personally seen the damage that can happen when people believe they know better than physics, so when I see dangerous things being proposed I tend to be to the point. You are welcome to take offense at that if you choose.
And finally, you are also welcome to try whatever you like at your own risk, just being aware of the potentially extreme danger and, too, that connection of a device in an improper or unsupported manner will void your product warranty.
As the correct answer was already given long ago, I’ll close this topic now.
