Victron Smartsolar 100/20 and boost converter on load output instability..

[sillared]

Running a Smartsolar 100/20 on a home-made 60ah lifep04 battery bank with a JK B2A8S20P-H bms. with 3 100w solar panels. Hooked up to this is a 19.5v boost converter that is powering an Asus AC68u router and a POE switch that has 2 Dahua POE cameras attached. Total draw of this system is 1.2-1.7 amps depending on if its dark and the IR is up and running. System runs flawlessly for about a week consistently, then the load output of the Smartsolar 100/20 kicks out and the the cameras/router shut down.... Power has to be disconnected from the Smartsolar to reset, then the system is back up and running for a week give or take.. 40 degrees out, 95 degrees out, same thing happens consistently...
Thoughts??

 

[sunshine_eggo]

Link MPPT settings including expert and load port config.

Approximate location?

3S or 3P Panel wiring?

Shading an issue?

 

[sillared]

I`ll look at settings this weekend... Its in Northern WI. Shading is not an issue, 3P on panels.

 

[sunshine_eggo]

The numbers indicate you have about 2 days of battery power. High latitudes and potential proximity to the Great Lakes are not typically conducive to PV.

Picking Rhinelander, WI, if you have your panels tilted at 45° facing due south, you should be able to produce 1.5X your daily need on average.



Based on average hourly data for October I see three stretches around 10/5, 10/12 and 10/24 where depleting your battery is almost a certainty. If your panels are not optimally tilted @ 45° or steeper, it's going to be worse.

When December comes, you will be hard pressed to provide your daily needs, especially if cold temperature charging protection becomes a factor. I'm counting 19 days where you won't be able to generate your daily needs.

 

[sillared]

You are correct, this is just a proof of concept to learn so far. The problem I am trying to address is not whether this is sized correctly, but why the load output malfunctions and shuts off when the battery is no where near depleted according to the log history in the controller. The battery can be 9 or 95% full and the load output shuts down and needs to be physically unhooked to reset. This occurs whether I'm set to always on, battery life etc etc. It's not a voltage setting causing the shutdown.

 

[sunshine_eggo]

I understand. Without being able to assess the settings, I had to let my brain roam where it felt it could do some good.

When connected to the BT module enter the Trends tab and select battery voltage and load current. It will log these for 46 days. Might yield a clue.

 

[sillared]

I`ll be up at the controller later this eve and can provide more info.. I`m wondering if theres an incompatibility between a boost converter and the mppt controller.. Thought I found a discussion on that several weeks ago somewhere, but alas, I cant figure out where I saw that... .

 

[sunshine_eggo]

I`ll be up at the controller later this eve and can provide more info.. I`m wondering if theres an incompatibility between a boost converter and the mppt controller.. Thought I found a discussion on that several weeks ago somewhere, but alas, I cant figure out where I saw that... .

Boost converters are pretty limited. Load terminals are always at battery voltage, so if the input voltage changes too fast or goes out of limits, the boost converter might shut down. The logging function might give clues.

When you have to restart the controller to restore function, have you checked voltage on the load terminals before restarting? If there's voltage there, but the converter isn't working, then the focus would shift to the converter.

Also worth outputting the 30 day detailed history of the controller showing daily kWh production, loads and high/low PV/Battery voltages

 

[MisterSandals]

then the load output of the Smartsolar 100/20 kicks out and the the cameras/router shut down...

You should be connecting your loads to the battery, not the SCC load output.

 

[sillared]

I hooked it to the load output so I could track consumption/charging in the same app. I can't find a max recommended load for the load output in the docs but seemed like people were running much larger loads than 2a thru the load output from my reading. The bms has a low voltage disconnect so I suppose I could just run off that, but I'd also love to solve the problem.

 

[MisterSandals]

Shading is not an issue, 3P on panels.

What is your panel Voc?

If you can change to 3S, you will triple the voltage and start charging earlier in the day, later in the evening and more likely meet minimum charging voltage on overcast days.

I know it gets mighty cold up there. Will definitely need to consider temp adjusted voltage. If you can get a 4th panel and run 2S2P, thats a good addition if 3S voltage too high.

I skied Indianhead and Blackjack at 30 below once as a kid. Paul Bunyan and Rib Mountain plenty too.

 

[sunshine_eggo]

I hooked it to the load output so I could track consumption/charging in the same app. I can't find a max recommended load for the load output in the docs but seemed like people were running much larger loads than 2a thru the load output from my reading. The bms has a low voltage disconnect so I suppose I could just run off that, but I'd also love to solve the problem.

Concur that a simple DC-DC converter is fine off the load ports. Cutting of loads BEFORE the BMS engages protection is ALWAYS preferred.

 

[MisterSandals]

System runs flawlessly for about a week consistently, then the load output of the Smartsolar 100/20 kicks out and the the cameras/router shut down.... Power has to be disconnected from the Smartsolar to reset

So in addressing your actual question... (sorry!)...
Do you know if its low battery voltage that causes your 100/20 load output to "kick out"?

I can imagine that if low voltage is hit, its plausible the load output does not turn back on automatically when battery voltage resumes (i dunno but it seems this may be the case).

@sunshine_eggo, are you familiar with what happens to load output at low voltage cutout when battery voltage is restored?

 

[pollenface]

The load output of my 100/20s stopped functioning normally after i went to 48v ... i pressumed they were faulty and worked around it

 

[sunshine_eggo]

@sunshine_eggo, are you familiar with what happens to load output at low voltage cutout when battery voltage is restored?

The MPPT should cut the load output based on the low voltage cutoff programmed into the controller. Given that the MPPT can power both load and battery terminals purely from PV (no battery is needed), I am dubious that we're dealing with a load port issue unless it's a setting issue. Sample with demo library:



Defaults to 24V system, so load port off at 12.8V and load port back on at 13.1V.

The load output of my 100/20s stopped functioning normally after i went to 48v ... i pressumed they were faulty and worked around it

There are two versions of the 100/20. One for 12/24V and one for 12/24/48V. I'm assuming the OP is dealing with the non-48V model. I'm not aware of anything that prevents functioning of the load ports with a 100/20-48V unit.

 

[sillared]

I have the 12/24/48 model, running it as a 12v system atm.

 

[sunshine_eggo]

Don't think it matters based on the settings in the demo library.

 

[Q-Dog]

Output at 48 volts is limited to 1 amp, but that isn't your problem.

I wonder if the 100/20 is engaging the battery life algorithm? It is a feature that cuts the load output in an attempt to get the battery to full charge. every day the battery does not get to full charge the unit reduces the load cutoff voltage until the battery gets to full charge. section 3.8.3 in the manual mentions how it operates.

 

[sunshine_eggo]

Output at 48 volts is limited to 1 amp, but that isn't your problem.

I wonder if the 100/20 is engaging the battery life algorithm? It is a feature that cuts the load output in an attempt to get the battery to full charge. every day the battery does not get to full charge the unit reduces the load cutoff voltage until the battery gets to full charge. section 3.8.3 in the manual mentions how it operates.

Yeah. That's why I'm eager to see the settings.

 

[sillared]

I THINK I have it figured out.. I think the POE switch I`m using is having some sort of brain fart/overload that is shutting down the load output. Currently its up and running, but I have a second one I will keep onsite if it continues to happen. With the poe switch plugged in and the smartsolar controller already tripped, I was getting .2-.4v out of the smartsolar controller.
When I reset the controller, the devices I had on the circuit would power up for about a half a second and cut out. Removed the poe switch from the circuit and everything ran just fine. Unplugged the POE switch funky power quick release and plugged back in and it appears to work fine.. For those interested, its a

Centopto Mini Industrial 5 Ports Gigabit PoE Switch Hardened​

More observation required, and I`ll keep you guys posted. Thanks for the input!

I`ve moved the battery to a yeti cooler since its going to be below freezing here overnight in the next week or two, and I the bms has a heating circuit I have 2 heating pads wired into... Tinkering is dangerous...