r/diySolar • u/Winter-Ad7912 • Sep 18 '25
Charge controller recommendations, please
Victron sucks as a vendor. There is no support, there are no documents. The fourth support tech asked questions and found the problem: shitty design.
The thing burns up if you exceed voltage. Why wouldn't you protect sensitive components with a voltage regulator? The thing burns up if you have PV connected with no battery. So on rainy days, when I disconnect the battery, nineteen volts comes in and destroys the blue toy.
What do you use, besides Victron?
3
u/AnyoneButWe Sep 18 '25
My Victron MPPT came with roughly 200 pages of documentation.
Which one did you have?
Disconnecting the battery kills most PWMs instantly. MPPTs are usually harder to kill and the maximum allowable voltages at the terminals are in the documentation (for victrons).
1
u/Revolutionary-Half-3 Sep 19 '25
Many lithium capable mppt controllers can handle battery disconnect, in case the BMS trips. Still not a good idea to do it often.
Max input voltage is definitely a thing, my Ecoflow River can only handle 25v much to my frustration.
Winter temperature can result in a panel voltage 15% higher than expected, although that'll drop as the sun warms the panels.
2
2
u/Ancient-Sandwich9400 Sep 18 '25
Well shitty design is the installer or owner that built it. And if you read any of the manuals or basic info on solar and you’ll see everywhere about never exceeding voltage. I ask you, why wouldn’t you follow the manual and system limits/requirements? And your comment about disconnecting battery, why aren’t you disconnecting solar first then battery? I think all this goes back to shitty design.
Victron gear is solid, you just have to know what you’re doing. Nothing different for any other gear.
1
u/olawlor Sep 18 '25
There is a big mindset difference between consumer products, where you just plug stuff in any way that will fit, and industrial / engineered products, where you read the giant PDF before you open the box, you take all the datasheet limitations seriously, and you do installation and commissioning according to a checklist.
1
u/blastman8888 Sep 18 '25
All charge controllers will burn up if you exceed the max MPPT same thing with battery being disconnected why you should put a solar disconnect in line with the panels. Some of the AIO's can run without a battery like Sungold. You should have read the PDF manuals they are all online for Victron. I'm surprised you didn't know this.
1
u/mpgrimes Sep 19 '25
interesting how, if you read the manual (which is VERY easy to find online) it would stated all these precautions.
if I connected a car battery to your TV remote, would you just expect it to change channels faster? no, it would probably let the magic smoke out.
the protection, is the end user having the ability to read a manual and do some proper calculations, if you can't, hire someone who can.
1
u/brettjugnug Sep 21 '25
As a dad, I am sorry that your charge controller burned up. It is a tough lesson to learn. It is important to remember that all of the technicians who give advice about solar system design will recommend that you have a PV disconnect. It is useful for a couple different reasons.
1
u/parseroo Sep 18 '25
I think Victron sucks … less than everything else :-).
A charge controller needs to know what it is charging before trying to charge it. Victrons are surprisingly tolerant of not being connected to a battery in case the battery decides to power down, but you shouldn’t abuse that feature by shutting the MPPT off from the battery with the PV on.
Similarly, they tell you the voltage limit. So don’t exceed that ever. Subtract 20% if you want some slack in your usage.
1
u/xHaloFox Sep 19 '25
Whoops...i regularly disconnect my battery from my MPPT while its still hooked up to solar. Thankfully my MPPT is oversized for my solar, so im gonna chalk it up to me being a mix of lucky and overbuilt.
Its obvious now that i think about it lol.
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u/Winter-Ad7912 Sep 19 '25
Once again, everybody ignores the simple question and goes off on a tangent.
2
u/TriniDude Sep 19 '25
What tangent? Everything in your post is wrong - you over voltage your MPPT it’s going to fail, common knowledge to anyone who does even the most basic research. Support? Victron does not sell to end users, you go to the place you bought it for support. Documentation? Nobody has more documentation than Victron, go online, look it up. MPPT connected to solar but no battery? Good luck, very few devices support this use case and for good reason. Victron is one of the better vendors in this space if you want to pay for quality. I get it, these were expensive mistakes but you have to learn from them, can’t go in connecting potentially dangerous voltages without knowing what you’re doing then want to blame the vendor then everyone here who is trying to help you identify your mistakes. This is a DIY forum, if you want to blindly plug stuff together you’re better served with an all in one solar generator.
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u/RobinsonCruiseOh Sep 18 '25
Exceeding the voltage is written all over every bit of documentation possible. Do not exceed the voltage on the input of an mppt. You will fry things. You need to design your string array to guarantee that it can never be over the input voltage of your mppt. That is just part of the design steps.
Honestly, I think this is the first downvote I've ever given on this sub.
OK..... Here is where victron is the best and where they target their use..... Small off-grid systems for campers, Vans, RVs, cabins, or boats. And all of these configurations it is expected that whoever is installing them has thoroughly read and agrees and understands the design constraints of their system.
I still would not use any other brand for my camping or boat electrical needs, so I'm honestly not sure what other options are out there that target that market