Why I go with Multiple Charge Controllers 

Thanks! You were one of first ones I thought of when it comes to redundancy! Take care!

@@OffGridBasement I also have 3 100/20 controllers in use. I also have the same inverter you have with a common bus for "+" and "-".. I have an eg4 24v lifepo4 200ah battery. My question to you is how do you midigate an issue where if for some reason the battery bank is switched off either via bms fault or battery disconnect left in off position, inverter freaks out. It is trying to take the 24v inconsistant power from common bus via controllers. Have u tested this? Or do you have a solution. Thanks!

@@mikecreamer8308 Mike, I had to read this a couple times to actually figure out what you're asking b/c it's pretty complicated and I've never thought of this scenario. To answer your question.. no. I've never tested this and I don't think I would want to. I think there would be a high possibility of frying up your charge controllers. I do know most off grid inverters need a pretty stable voltage in order to work properly. Any amount of instant draw would drop the output voltage of the charge controllers and the inverter would freak. After the inverter shuts down is when you could see magic smoke from your charge controllers. I don't really know if this helps or not, but I really hope I never come across that scenario! Thanks!

@@OffGridBasement it wont destroy your inverter it just goes in and out of low voltage alarm until the sun goes down and or the connection to the battery is restored. Inverter beeps like crazy, and it is a possible hazard. Just wanted you to be aware of this. There is no communication to tell the controllers to stop charging if no voltage present on bus or the capicitor voltage from inverter it thinks this is battery and it essentially boot loops

​​​@@OffGridBasementhave you found them fighting each other? We have two. They produce 1/2 what we expect from each one. On your best mppt, at best time, what % of the rated total solar panels wattage do you see out of best mppt? In our case we have two 250w and only see about 125w on the best day at the best time out of each mppt. That's around 50% - 60%. And who do you call for support? Victron has no US phone support?

Glad to help and thank you for the comment.

I couldn't have said it better myself. Thank you for the info and the comment!

"...be sure to keep the output wires the same length." - I'm just about to connect up a pair of 250/60 MPPTs to my array of 16 x 425w panels arranged as two parallel strings of four series connected panels for each controller. My controllers are mounted side by side so the DC cables would naturally be different lengths. Can you please explain why equal lengths of cables are important in this context? I totally get why battery cables need to be the same length to help with cell balance but why do MPPTs need equal length cables? Thanks. Edit: I found some info on page 38 of working unlimited where it says "...solar chargers need to have approximately the same cable length" but it seems like it's not as critical as the inverters or batteries. I'll see if I can find a way to route the cables to keep the length similar.

Fantastic addition. Thanks a lot.

Very true. I do have a neighbor's tree that sends shade over my panels, but it only effects one string at a time. Thanks for the comment!

This is a factor even I hadn't considered...

Oh neat. Powerlines cast a shadow on my van when I park in my spot. I have two controllers now. I can separate the back half from the front.

3 billion years of terrestrial evolution . If one big unit was better, we would be one giant cell.

How did you confabulate that number? ​@@5400bowen

Ahhhh... Isn't that the dream? I would love to be totally self sufficient. Thanks for the comment.

Thanks for sharing and the comment!

Thanks for the comment!

Glad I could help! Thanks for the comment.

That's a great reason to have multiple charger controllers. Glad you like the videos and thanks for the comment!

Glad to hear it! I figured you should just expand as needed. Thanks for the comment.

Yes it is! Sounds like your system is well setup. Thanks for the comment 👍

Thanks for the comment. It really helps.

Good points! I personally don't like putting all my eggs in one basket, but it looks like you have that covered as well. Thanks for the comment 👍

Yes. I know plenty of people that have a big inverter for large loads and a small inverter for all of the smaller loads. Thanks for the comment.

@@OffGridBasement and you would turn one inverter off overnight. Like running 2x 3kva multiplus. And when not needed on inverter can be set off.

I love stackable inverters for this very reason.

@@crinabobo7412 Absolutely. And have all the "Power Vampires" like the Phone and Laptop Charger Bricks be plugged into a plug strip on that one.

I would feel safe using Victron with SLA batteries since the charge controllers get the voltage from the battery monitor. That is only if I had all the equipment I currently have. Not having the battery monitor would be a different story... Thanks for the comment!

I use 4 very cheap pwm controllers on one flooded lead acid battery bank and manage by useing the controller with the largest number of watts as primary and set the others to a lower cut off voltage..

@jamesalles139 - Bu the is no redundancy here. There is three independent smaller MPPT's, they offer zero redundancy.

That is such a great compliment! Thank you!

​@@OffGridBasementsir if we have 2 different solar charge controller attach to 1 battery is this charge battery properly?

That is exactly what I'm talking about! Thanks for the comment!

Even though your calculations are correct, I don't think the logic is correct in this situation. Each CC can handle up to 100v of Solar. I have two of them so they can handle up to 200v of solar. They are not in parallel. They are completely different strings. Also, each CC can supply up to 30A to my battery. On this side of the charge controller they ARE connected in parallel so I could get a max charge of 60A @ 24V One 150/60A CC can handle 150V of Solar. It can supply up to 60A to a battery. This is also 60A @ 24V. Granted, this charge controller can handle 36V and 48V so that is why there's an additional cost I'm guessing. Each 100/30 CC is currently $224.90 so if you had two the total would be $449.80 One 150/60 CC is currently $539.75. These prices are from Amazon. I believe that is the point I was making in my video. Please let me know if I am wrong. Thanks for the comment!

@@OffGridBasement thanks for the reply, unfortunately you cant just add the voltages and current like that. Even though the inputs (solar) are separate strings, combining them would not add the voltages and the current together, if we define the charge controllers by their maximum output in W it makes it much simpler. I have taken these values from the product datasheets. For a 24V system: PV power ratings: 100/30= 880W 150/70=2000W The 150/70 controller is severely limited by the use of a 24v battery in this use case as you cant access the extra power headroom due to the current output limit on the controller. Yet we still see a 227% increase in capability. Or let me explain in a theoretical situation: If you were to have your 100/30 controllers maxed out with solar, for example 3 panels with 33.3Voc and 5A Isc in series and 6 in parallel for 18 panels (making 150Voc and 30A Isc). Lets not worry about over-panelling for now or margin for Voc. if you had 2 of these CC setup, you would have 32 panels. those 32 panels would not produce 200V at 60A, you could get 200V at 30A or 100V at 60A, not both. This is the theoretical limit of these controllers. For the 150/70 for the same theoretical panels you can connect 4.5 panels in series and with a total of 14 parallel strings. Meaning a total of 63 panels could be connected. That gives you theoretically 197% more capacity with the 150/70 controller compared to the 100/30 controller. The additional cost if for the higher power components that can handle higher voltage and current, hence higher overall wattage etc. The larger controller would provide much better value for larger arrays that don't suffer from partial shading much and are in the same location. Also the ability to connect a 48v battery opens up a huge amount more solar, since the current output of the controller is capped, having a 48v system doubles the amount of panels you can add to a system compared to a 24v system, as you are usually capped by the charge current of the controllers.

The above is why as you move to larger solar power systems, 48v batteries start to make a whole lot more sense, I hope I haven't inadvertently persuaded you to upgrade to 48v 🙃

not always true..if u already using pv 800watt with 100/30 charger control..and next time you want upgraded power to 1600w..old charger control not support,save a lot of money u just buy 100/30 not need to waste buying 150/60 charger control..

I've never regretted spending the extra money. Well worth it. Thanks for the comment.

Thanks for the comment! If there is anything I can help with, please let me know!

Very good point. Thanks for the comment.

I agree. I don't think I would feel comfortable with using a all-in-one unit. The smart version is so nice! If you can add it, you won't be disappointed.

It's hard to stop once you start down the victron road! Thanks for the comment 👍

I'm not sure how you would pull off a two stage dump. It would almost need to be on a timer. Once the first stage starts then 5 minutes later if the voltage is still above a certain level then the second stage starts. Once the voltage drops then both stages stop. I don't know of a product that would do something like that automatically. Good luck with your adventures in silliness!

@@OffGridBasement Thank you. Starting to think I'm going to need an Arduino or Raspberry Pi. Especially since I want to set up the Money-Maker bank to automatically drop its banks to 25% once full.

That is a very good point. Thanks for the info and the comment.

My thought was to upgrade to a 1000w w/ limiter, but I also read about how the unit can be damaged if disconnected for the grid via a smart plug. I guess it does its "islanding" from the clamp limiter. if the limiter doesn't detect amps it disconnects. The 600w I have disconnects when it doesn't detect amps in the plug. At least that is my understanding. With that being said I feel the unit I currently have is better for my application. I also believe you can program the Y&H unit to disconnect when the input voltage drops below so sort of threshold. Ex: 25v disconnect voltage.

Thanks for watching!

Thank you. I really does work out very well! Thanks for the comment!

It sounds like you have quite the setup. I've always felt like the video wasn't that smooth. Thank you for your honesty.

@@OffGridBasement I have a bit of money into it. Just wish I was not such a dummy about wiring. I want my multiplus connected. I'm saving to buy some land and go off grid. With a properly setup up solar system and RV.. it won't be too tough. Well.. off to town I go.. I'm in S. Oregon, how about you..?

@@Mywhtjp That sounds like a wonderful plan. I lived in Grants Pass for a couple years when I was young. I'm in Central Illinois.

Yes. I guess you could see it as a RAID setup. Never thought of it like that! Works great though. Thanks for the comment!

@phillysupra - No, it is *not* like RAID. If he loses one MPPT then he loses 1/3rd POWER. RAID does *not* work like that. He has 3 small *independent* MPPT, that offer zero redundancy.

@@MrSummitville I fully understand how raid works and it's different types redundant setups

Yes!

I should've just kept it simple... Thanks for the comment!

That's great! I'm going to be receiving another solar generator from FlashFish next week. Review coming soon! Are you looking into Grid Tie or Off Grid systems?

Thanks for the sub! Connecting a second charge controller is very easy. I have a video on connecting my third: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-dpxF1eg7UQQ.html It's even easier if you are connecting the same size controller b/c you can just save your settings on the first controller and load it onto the second controller. Super easy. Wiring is the exact same as the first controller. You will need to re-arrange your panels into 2 separate strings. Good luck!

Is it 12v or 24v?

@@OffGridBasement 12/24/48/60v and 60 or 80A , I'm looking at this because I'm using fangpusum 50A but I want to get more lasting power supply. to be sincere i don't know which to invest on to improve my power, I want it to last longer when there is no sun because I don't use any electricity all I depend on is solar system that I have, currently I have 4 batteries(24v system ) 2.5kva inverter and 6 panels charging. I have been asking people and some say I should add more panel, some say I should buy 1kva inverter cus it consum less energy and last longer without sunlight. please help me out sir

@@OffGridBasement still waiting for your reply

@@LifePhath honestly the only way to get more power is by acquiring more battery storage. Getting a smaller inverter will only save a small amount. Does your battery bank get to 100% most days?

@@OffGridBasement some days it gets 100% (it last longer)

I personally didn't think about it because I never intended on pushing my system. When I upgrade my inverter I will DEFINITELY be replacing the particle board with Hardy.

Usually they do 12 - 48v, but you would definitely want to make sure.

Thanks for the comment!

@rocktech7144 - There is no redundancy here. If he loses one MPPT, then he loses 1/3'rd of his power. Three is three. Two is two. One is one. None is none.

I'm actually working on that now. I'm getting a 6 circuit manual transfer switch for my house and everything is going mostly toward powering it. Thanks for the comment!

No. The charge controllers communicate with each other through Bluetooth. I've never had an issue. Thanks for the comment!

All you need to do with the Victrons with blue tooth or the smart dongle is to set up Ve networking and assign them to the same network. Its VERY each. Also, I highly recommend the smart shunt and the smart battery sense/ temp unit as that data is shared with the same network.

@@Gary-wh7ce Hi. This fixes problems with units limiting each other to float voltage? A few reviews on Amazon mention this problem so I was scared to recommend these as a way to slowly build up capacity by adding another Victron when funds allow.

You'd just be transferring energy from one battery to another with a bit of conversion loss. At some point you would need to recharge everything from somewhere. Thanks for the comment.

Not if input is greater then output

Thanks for sharing. I'm glad everything is working for you.

I can't find anything that will do that. Both circuits would need to be switched at the same time.

I actually disconnected it. I don't need it during winter. I'm also working on something so I don't need the grid tie any longer. The unit still works great. I think keeping a separate fan on it made a big difference. Thanks for the comment.

Wow! That's a good way to go. I'm surprised that wiring in parallel didn't work for you. Thanks for the comment and info.

@@OffGridBasement "I'm surprised that wiring in parallel didn't work for you." Each charger is rated for 30A to the 12v battery bank and the panels for 13A into the charger, so it is a good match. Also I can monitor each panel's individual performance and move it around accordingly as the sun/shade moves around according to seasonal changes.

The two 12v batteries are in series, but the charge controllers are in parallel. I love Victron as well. I definitely don't regret spending the extra $$. Thanks for the comment.

The voltage would remain the same but amperage would split. I just don't know how evenly the split would be. I'm sure it would be 50\50. Thanks for the comment.

I don't believe so in my case. All of my strings have different amps / volts so I think it would cause issues. Thanks for the comment!

@@OffGridBasement Mine also have different voltages and amps. Another analog would be combining all negative poles of some 1.5, 3.6 and 9 volt batteries. A meter with a probe to combined negative and another on the positive of the 9v battery will read 9v. Currently I have 4 negative conductors feeding 4 controllers from 14 feet away from the cable entry point. I'd like to "terminate" them to a copper bar and run a single cable to another copper bar that would use very short 10 gauge wires feed the controllers. I also seem to have seen that the negative solar inputs should be earth grounded ? Anyway no one has all the answers and I greatly appreciate your input. Last thing, I've purposely installed 2 smoke detectors in my basement solar area. Things made in China seem to burn. In a previous life I was a electronics technician working on communications equipment, I've seen capacitors explode, high power RF transisters fry and chokes vaporize ! The difference is those were properly engineered products with purposeful shielding, thus a lower possibility of risk, stuff from the CCP is absolutely garbage spare a few brands. So most folk have a solar shed, I'm in the process of moving all mystuff outside. Here in Virginia it rarely gets below 10 degrees so I will just put a incandescent bulb in the shed to warm up. Thanks for your channel and remember "folks that are experts know a lot about a single thing, but us DIYers know more bout Everything ! "

@@lovasjj I think panels essentially operate differently to batteries. If they are mismatched when connected they feed into each other and can cause them to short. I speak under correction but I would be very sure first before potentially frying panels

I certainly agree caution is needed. I do enjoy examining situations that logically make intuitive sense but require deep consideration. Many power systems today have common negative grounds but isolated positive poles. A automobile that has 12 volts across its starter fan or vehicle running lights will also have a common ground 5 volt regulator for the onboard computer. All these devices ( solar panels, the battery analog in my previous post or an automobile ) are DC devices and all have common rules. Indeed you can't simply hook a 5v and 12v source in series or parallel. Nor can one expect good things from hooking devices with equal voltage but differing output current in series. My question doesn't involve either principles. I cant see any issue with it and frankly that bothers me. Perhaps a simple way would to check for continuity from the controllers negative solar input to its metal exterior heat sink. If presant hooking up 2 or more controllers, mounted on a metal plate would create the exact scenario I've talked about. More study needed ! Thanks for reminding me of caution ⚠️...

@@lovasjj haha if you ever do come to a definitive answer I'd love to hear :)

You really need to read the manual. There are a lot of variables that need to be taken into account.

The Victron charge controllers all communicate with each other. That way they all go into absorption and float mode at the same time. Thanks for the comment.

They are connected through a Bluetooth connection, but I don't believe you would want to connect them physically through wiring.

@@OffGridBasement thanks... that makes sense.

I believe it will work just fine.

@@OffGridBasement did you try to bluetooth pair a victron smartsolar charger with a smaller one . WITHIN their power specs.. ? i dont want to push 100% on any part but might need to buy bigger one maybe 150 series one because new big panels come in 48v and 96v limit of the 100v series is too hard to maintain in any series which i might go !!!! thanks i still want to use the small one for start in another array .. maybe both are going for about 16 amps average on different angles pannels.. my problem still apears because i cant series 3 of my pannels and if i purchase 48v panels then i can use only one series of them.. buying another 100.20 .. then the losses due to low power matching panels will be doubled!!! my guess is that it can be bluetooth pairing as long as they both are smart solar but i wont go and buy on a single guess ! thanks again ..

Yes. Each controller is a different string of four panels. Two strings are 800w and the other is 1000w.

With PV connected in series, each battery connected in series, can we charge with separate controls with a single PV without separating the batteries from each other?

Each controller needs its own PV input (wish you could just use common buss bar). But multiple controllers can charge the same battery@@KutsiTekin

I've never heard of wiring solar charge controllers in series so I've never tried it. If it doesn't work then you destroy some expensive equipment. I honestly don't think it will work and you would burn up your equipment. I might be able to test that theory with what I have. Thanks for the question and comment.

@@OffGridBasement Its ok. Thank you.

That is exactly the same setup I have today. It's worked perfectly. I've never had an issue with it. I'm planning on making a follow up video of the PVC stands and how I have them secured to the ground using ground anchors.

@@OffGridBasement that way uld be great thank you. I have 12 panels to put out.

Thank you for the information and comment.

Since they are all smart victron mppts l, they communicate with each other through Bluetooth. That way they all stay in sync. Hope that answers your question. Thanks for the comment.

The vicron uses VE network to associate and coordinate the output. My system also has a smart shunt and a smart voltage sense / temp sense unit. Also, keep in mind that BOTH or MORE of the controllers need the same settings for float, bulk, etc otherwise the application will yell at you. My system also has morningstar and midnite solar controllers and all you have to do is again use common settings for the battery target. I call it solar salad.

Yes! As long as they are both using the same profile settings. Same bulk and float settings. If you can have the same length of wire going to the battery from both controllers it helps.

@@OffGridBasement thanks for the help sir..im now using two scc now in one battery and its working fine.🙏🙏

It's a 24v system so the CC can handle over 900w of solar. Thanks for the question and the comment.

I've had mine for almost 2 years now and they still work flawlessly. I'm hoping they last as long as the batteries. Around 10 years.

Usually a 30A controller can handle 100v. Make sure the open voltage of the panel is lower than that. If you multiply 30 x 12v you get 360w. That is the max a 30A controller can deliver @ 12v. Hope this helps.

@@OffGridBasement yes it did. Just that I noticed the max amps my 360 watt panel gave was just 19 so far, most times cos of the weather is around 4 to 17 amps with average of 11 amps daily. Was thinking of making it 460watts on 30amps charge controller

@@basilkasimi2646 as long as you don't go over 100v from the panel you will be just fine. Just remember if you get a 460w or a 540w panel the most you will get from it is 360w on a nice sunny day.

The honest answer is this: A PWM controller will pull the pv source down to the approximate battery voltage. By doing that, you only get a very small fraction of the wattage available from a panel. Therefore, it makes NO sense to have a 360 panel on a PWM 12v battery! You will get much better performance an charging current my replacing it with at least a 20A MPPT which will max out the 20A MPPT. But at least you can always use a PWM on smaller 100 watt panels in parallel to match the nonimal battery voltage. Try it out and test it......I have done this numerous times and only use PWM now for diversion control @@basilkasimi2646

Perfect!

@solarandwindinsouthtexasda1473 - Even with 6 controllers, you have zero redundancy. You just have 6 *independent* MPPT's. If you lose one MPPT controller then lost 1/6'th of your power. That is *not* redundancy.

@@MrSummitville you are right but I have three more charge controller put away

That is the shortened version for sure. I just wanted to make sure I covered everything. Thanks for the comment.

@herbertvonsauerkrautunterh2513 - There is no redundancy. He has 3 smaller independent MPPT's. If one MPPT fails .. it fails ... and he loses 1/3rd the of PV power. That is not called redundancy.

Lol... Sure I get what you mean but you're also a know it all picky woman.. There is redundancy built in. That's the way I would see it as the system still keeps working.

I've been trying to figure a way to get them raised up, but I have very limited space due to my HoA.

The math is sound. I'm not stating that the charge controllers are putting out 200v @ 60A. I'm stating that each charge controller can handle up to 100v with the ability of pushing a max of 30 Amps into my bank. With 2 of them, you can possibly handle up to 200v of solar panels with the possibly of pushing 60A into your system. I hope that clears in up. Thanks for the comment!

@@OffGridBasement I am referring to combined output. It's 1 or the other. 2 units cannot give you double voltage AND double current. But I actually doubt you could put them in series effectively, so best you can get is 100v@60A.

Man, I would LOVE to be able to say that. Everything on that wall I bought with my own money. Thanks for the comment.

If you're talking about the refocusing of the camera.. yeah... that's a bummer..

My meaning is if one of my charge controllers fails then I'm still running @ 66% opposed to having one big charge controller that fails and I have nothing. I guess redundancy isn't the correct terminology but I hope you get the idea. Thanks for the comment.

I think he means he doesn't lose the entire system if the only single controller he has were to fail. Still makes sense to me. Better lose a third than lose the whole lot...

I get the feeling you're listening to one right now! Thanks for the comment.

Thanks for the comment

I've personally never had any issues with one controller doing something different than the others. In my situation, the shunt might be a big help since that is where all of the controllers get the battery voltage.

The prices have really changed since the making of this video. Thanks for the comment.