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smart solar charging behaviour

Victron Smart Solar MPPT 150/85
I have 4 panels each 275W. The Voc of one panel is 38,8V and Inc is 9,17A. All panels are identical.

I have connected the panels so that two panel are connected in series and then these two two panels group is connected in parallel. Then I have a solar panel group with Voc 77,6V and Isc 18,3A. The total power of the system is 1420W. From that system I can get in to my battery bank of 12V a current of 118A. Is it so that I can get only 85A because of my existing 150/85 solar charger? The 33 A is not allowed to let in the battery bank from the solar charger?

If I will get all the current that is possible from my panel system of 1420W I have to buy another solar charge controller and connect that with two panels of 275W connected in series and connecting the other two panels connected in series with my existing MPPT 150/85 charge controller.

The solar chargers right size would then be 60A? The maximum current that is available from two panels of 275W  into my battery bank of 12V would be 59,2A.

A little bit cheaper would be a MPPT solar charger with maximum current of 50A? 

If I now have two solar chargers both connected with two panels is that system operating correctly so that both chargers are charging correct the battery bank? The connection with the battery bank and both solar chargers I will dot with my Victron LYNX IN busbar.


hanski asked
hanski commented ·

1 Answer

Showing 0 watts and 0 current on smartsolar 75/15

My SMARTSOLAR app on my android is showing 0 Watts. Decent sun out today, panel is clean...just looking to make sure my new solar system on new RV is working. Not sure as I am looking for some hint via the solar wattage...but has yet to move off 0. Any suggestions on how to run a diagnostic, etc? Can I use a multi meter on the unit rather than jumping up on roof?

cbatsford asked
cbatsford answered ·

2 Answers

MPPT 150/100 died


Howdy trying to investigate this failure with my MPPT 150/100. Installed new solar panels and updated the battery wiring since the factory gauge (RV) was small and came from the factory cut / with exposed copper on the red wire... On battery alone with PV cut off, no lights and no longer available on bluetooth. Did notice a few hours before that it was 'rebooting' frequently / the bluetooth was not stable. It is connected to a Venus/Cerbo GX (w dual MultiPlus 3000VA 12v and 1,000 amp smartshunt). during that time, I noticed the battery configuration was wrong and corrected it (settings showed 24v battery, but was 12v). But found that the corrections did not stay. I wasn't sure if it was because Venus/CAN was setting things up and the configuration was no-op or not. But looking at the graphs, it looks like around the time of the failures it legitimately thought 24v and was not saving the settings, but you can see previously it did not have that issue. Back to the wires, 2ga (US) from panels and to battery (wasn't sure what to put on battery side so decided larger would just lead to less efficient charging on lower end, but not leave me in a pickle on the higher end.)

Questions I'm trying to solve:

  • Is any of this expected?
  • Is this something that I should warranty? - less than a year in service and $800 USD
  • How do I know replacing the MPPT 150/100 won't cause the same issue again?
  • Is it possible the wire sizing caused this?

Graphs :) - the missing time period is when the charger seemed to die. When that happened the multipluses also went down- so unaware of what happened during that time. Might be time to install a UPS for the "home lab" in the RV.

Battle born batteries 12v. So 14.2 is right.


Here 18.9v is, quite wrong. I think this is going back to that 24v setting I mentioned.


nothing out of the ordinary with the pv


if you're curious about multiplus since that would be the other feeder of dc voltage


Not seeing anything unusual on the battery either,


Oh, one thing that was weird too, the battery terminals:



Myles Best asked
Myles Best answered ·

2 Answers

BlueSolar 75/15 -- 12v PV in to 24v bank?

this has been asked before with no satisfactory and definitive answer:

can a 12V PV maintain a 24V bank?

what does one need to do in order to get this to work? connect the battery first, to establish V being 24V, and then attach the 12V PV to show the input current? is there any built-in buck boost in the BlueSolar 75/15?

I have read that a BlueSolar MPPT 75/15 will only start to charge when the PV output V is 0.5V more than the current battery bank V, then stop when it is under 0.1V, but does that mean that it absolutely will not work as 12/24V dependent/congruent system?

will it work from 24V PV to 12V bank? why not versa vica?


andersonmiles asked
kevgermany answered ·

2 Answers

12v Batteries Not Charging to Full / MPPT remaining on Bulk Charge

We have a 200AH x 12v battery setup with ~1.2KW of solar panels (2 x Trina 330W and 2 x 250W Generic) and a Victron 100/50 Charge Controller. The House is in full sun and there is very little / basically no draw from the house but for some reason the panels are not charging the batteries enough. I'm wondering if there is some issue with the panels not being setup correctly? They appear to be in parallel as the voltage is barely over 18 and the amperage is very low. Any ideas?

Screenshot 2022-11-08 194220.pngIsabella (Orange NSW) ROB - VRM Portal.pdf

james09 asked
Alexandra commented ·

1 Answer

SmartSolar 150/100 Volts, No Amps, Battery Drained to 0


New to the community. Full Victron install, 600 ah of Lithium, 1440 watts of solar, Multiplus 3000 inverter. 12V system. Everything has worked great for a couple months. 6 days ago I stopped getting amps from the panels. Nothing changed. Battery died over the course of 5 days powering my mifi in storage.
Temps were good. At night I can access the charge controller so I know that the controller is connected to the battery and seeing the voltage. Anybody have any ideas?



big-chungus asked
big-chungus edited ·

7 Answers

Smart Solar MPPT 150/85 MC4 charging 12V, 24V, 36V but not 48V

Hi everyone!

I've got a 16S 48V LiFePo4 system with a Smart Solar MPPT 150/85 MC4. ~80V OCV with 4 ~300W panels.

Been having issues with the MPPT charging intermittently. I switched BMS a few times thinking that was the issue.

Now the MPPT is not charging more than 0-10W/0-0.1A while in Bulk. I've connected the MPPT directly to the battery pack (without BMS) for troubleshooting to eliminate any other issues.

The MPPT charges perfectly when:

- connected to another 12V battery

- connected to any 4 connected cells of the 16S LiFePo4 assembly (set to 12V)

- connected to any 8 connected cells of the 16S LiFePo4 assembly (set to 24V)

(only charging for very short time and same time to avoid imbalance ofc)

As soon as I connect it to all cells at 48V it stops working.

I've checked battery continuity, individual cell voltages, cell connector bars. PV strip continuty is perfect, been charging a Bluetti unit at 750W without issues.

I've scoured this forum and tried everything remotely applicable.

The MPPT is configured with standard LiFePo4 settings. Charger is on, jumper connected and ofc it charges at <48V.

Is it possible that only the MPPT 48V charging circuit broke? Am I missing something?


123dyonisos asked
123dyonisos commented ·

1 Answer

How to charge canopy battery when car is running by alternator and at the same time charge with my solar panels?

I have a redarc bcdc 50a charger and want to use it to charge my 280ah lithium battery when driving and add a solar blanket when stopped. I also have 2 x 170w solar panels on my ute canopy and a mppt 100/20 victron. How can i set my system up so my battery is charged simultaneously when driving by both redarc and victron mppt?

jackormark-82 asked
Kevin Windrem answered ·

1 Answer

Multi RS Solar uses Grid instead of PylonTech and Solar panel

Hello Everyone,

in my father's house I have installed the Multi RS solar on PylonTech barltteries. thanks to other users in the forum I have managed it to make it running. if there is consumption on the deducted AC output, unfortunately the system prefers to switch directly to the grid and ignores the full batteries. only if ACin is switched off and the system is disconnected from the grid, it switches to the batteries.

I can imagine that this mode makes sense in mobile homes or in a boat. In my parents house it makes no sense this way and I have to put down the fire manually each time I want to use the batteries.

is there a setting that I haven't seen in the software? can someone please give me a hint?

thanks again to the community!



elmar-streich asked
semlohnhoj commented ·

3 Answers

Solar Invertor AC coupling of Mulitplus on AC input?

Hi all,

The context of my question is for a grid coupled solar system with local battery.

I've been reading documentation on the Victron (MultiplusIIGX) and some posts here on AC Coupling (

What I've understood so far (
- AC Coupling is done on the output of the MP/MP2
- Rule: MP2 Power rating >= Solar invertor power rating
- Battery capacity (Lithium): 1,5 kWp installed AC PV power requires 4.8 kWh of battery storage

The questions I have:
a) Is there a hard requirement to couple the solar invertor on AC Output of the MP2?
b) Can some of these rules not be avoided by coupling on AC Input (see reasoning below)?
c) How to control the MP2 to only charge the battery when there is solar power available?

I found this post ( but very little other info.

The reasoning for this question:

Suppose the MP2 is coupled to the grid/solar invertor on input: i.e. the Solar invertor generates power if there is sun, and injects into the grid when there is not enough demand. The MP2 takes care of the loads coupled on the AC output, i.e. when there is demand and Solar power available in the AC input the loads can be fed from the AC input, when there is no solar the loads can be fed from the the battery and if the battery is depleted the loads are finally fed from the AC input (i.e. grid).

In this way the power rating of the MP2 can be selected in line with the power required by the load behind the MP2 and the battery can be sized accordingly.

For a household, a big part of an electricity bill is caused by low power devices that are powered for a large period of time, i.e. (led) lights, routers, clocks, computers, ... -> i.e. a large part of the bill could be avoided by a relatively small MP2/battery system.

The only thing I've not found is to control the MP2 when to charge the battery, thus only charge the battery when there is solar power or when the grid is cheap.

What am I missing?

Thanks for helping out.

Best regards,


rubens asked
rubens commented ·

1 Answer

Not had a yield for the past 3 days?
What could be wrong? Thanks for any help!



sam-smiler asked
christern commented ·

4 Answers

Which gets used first for a load, solar or battery?

Had a search and couldn't find an answer, I'm sure there's countless ones out there though.

If I connect panels to the CC PV terminals, a battery to the CC battery terminals and a DC fuse box to the CC load terminals, how is current routed? Say PV was 5A and the load was 2A, would 2A from the PV go straight to the load and 3A to charge the battery?

Many thanks

brockles asked
Alexandra answered ·

1 Answer

SmartSolar 100/30 MPPT Battery Voltage Fluctuates on App

New here. I have a SmartSolar 100/30 12V. I noticed the APP says Battery Voltage of 7.36 to 8.94 and sometimes spikes up to 13.xx or so.

I measured the voltage at the battery terminals on the 100/30 with my Fluke 87. It says solid fluctuating only at 13.29 to 13.30.

I have checked all of my connections. Everything is tight.

Settings; Pos 7, Battery Voltage 12V, LiFePo4, Temp Comp Disabled (all standard settings for Pos 7)

1) In Bulk Charging. Should this read the actual voltage measured at the Battery Terminal on the 100/30 or is this normal?

2) It says Firmware is v1.59 Bluetooth Interface (Rev2) Firmware v2.41 Bootloader v1.16

Thanks for any clarifications!

fulltime-2020 asked
fulltime-2020 answered ·

2 Answers

Electric Acting Up in Van

Hey there,

For the past few months the electricity in my van has been acting strange. Full transparency, I didn't do the buildout nor have a firm graph on the electric setup so I'll detail as best I can. (warning: it's a lot). Appreciate your help in advance!!

tl;dr - Electricity surges and drops overnight

Here is our setup:


(2) 6V Deep Cycle Batteries / 200 Amp Hour AGM battery bank (~3-4 years old)

12V 140 Amp Dual Battery Isolater - running off engine batter


  • (2) 275 watt Lg Solar panels
  • Victron SmartSolar Charge Connector MPPT 100 | 30

We're typically only running the main cabin lights, a Nova Kool R3800 Dc Refrigerator, Maxxair fan, and a small bathroom fan (only when bathroom is in use).

What's been happening:

- We first began experiencing what I'd call a 'surge' this Spring. The things mentioned above would be running fine then the lights would turn off/on rapidly, fan would turn off it is was in use (on if it wasn't in use), same for bathroom fan. This happened for 10 sec or so then repeat a handful of times. We typically turned off the fan breaker and turned off the lights until we needed them on again.

- On a trip last month, we weren't as much experiencing the 'surge' but instead woke up to water on our floor as our fridge defrosted overnight. This happened multiple times and the fridge struggled to function for the rest of the trip.

- We also had a few small water leaks in the van roof over the past few years. Only mentioning in case it sounds like a faulty wire (which I haven't yet seen).

- Lastly, the lights have turned on by themselves overnight. Outside of ghosts I can only imagine the system is turning on during a 'pulse'?!?


I've been doing more testing on the batteries. During the day (full sun), they're both tracking around 5.8-5.6v (per battery). In the early AM (around 6-7 before full sun), one remains around 5.8v while the other is lower at 4.6v. I have seen dips into the 8-9v when checking at night/early AM (which is the measurement for the 2 batteries combined). With full sun, we're typically 11-14v.

Lastly, I also noticed a quick drop in voltage around the pulses I've mentioned.


If you've made it this far in the post, thanks. Appreciate your time.

Is it as simple as I need new batteries or does it sound like something else is going on?

bridgeskd asked
marekp commented ·

2 Answers

SmartSolar weird absorption duration

Hello. I use a SmartSolar MPPT 100/20 (48V model) on a (partly sulfated) 12V AGM battery, with VictronConnect's AGM spiral cell preset (i.e. 6h max, adaptive duration absorption, and a 1A tail current that has never been reached). Firmware is 1.59.

With 12.4V-12.5V in the morning, absorption lasts 1h-1h6m when it should last 2h (1/3 of max duration). I chalked it up to an unstated gradient of the applied factor. However, this morning, my battery was sitting at 12.71V but the absorption phase lasted 2h19m. Any thoughts on this?


Erendil Lo asked
Erendil Lo commented ·

1 Answer

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