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Stopping my MPPT from charging around 80% SOC while the RV is in storage

I have seen other questions like this but the answers were more about folks NOT wanting to do this. I am trying to find out how to do it. I am assuming maybe by changing the voltage, I tried lowering the float voltage to 13.5 from 13.6 and it had no visible effect. Instead of trial and error I am hoping to start in the correct area as my storage facility is far away. (I monitor it via VRM)

PS. I want to do this, so I don't need any info on why folks don't think it needs to be done, I have read all that and still want to do it anyway to lower the cycle count on my older LI batteries.

bigbillsd asked
bunya-solar-pl answered ·

1 Answer

Charge current incorrect on Venus Venus GX

Hi there,

I have recently doubled my storage battery from Pylontech US 3000 (3.5kW) to 2x US 3000 (7.0 kW

I am running MPPT 150 / 45 Solar Controller and Multi Grid 48V/3000VA/35Amps Inverter / Charger.

The displayed charging current and Wattage seems to be that of only one battery as it does not compute up to the display on solar yield vs consumption.

I have connected the data link from Master battery Link Port "1" to Slave battery Link Port "0"

connection to Venus GX is from "CAN" port

Any advice please

Walter Gygax asked
Alexandra answered ·

1 Answer

SOC fall down over night


In my system (Multiplus 2-48, GWL 4,8 kWh, Venus OS) falls des SOC overnight quickly from 75 % to 10 %, but no big consuption or feed was observed. Battery life was activated.

What can be the reason?

anddittma asked
Paul B answered ·

1 Answer

Victron EV charging station + ESS configuration possibilities

Hi guys, this may be a question for the Victron team. I am looking to purchase the new EV charging station, but i have some questions on how it can be configured together with a grid bound ESS system, i could not determine the answer myself on the available documentation or video.

This i was able to find: In automatic mode it will only use excess energy when the home battery is fully charged, and in off grid systems it is possible to set a minimum SOC for the home battery.

My questions:

1. Is it possible to set a minimum SOC for the home battery in a grid bound ESS system before the EV charger kicks in? For example, when the ESS minimum SOC is lets say 20% before getting power from the grid, can the minimum SOC for the EV charger be set at 50% at the same time? In this case the EV charger would use the home battery from 100% to 50%, and the remaining 50% to 20% would be reserved for domestic use at night. Would the EV charger stop using the home battery at set SOC, and only solar power afterwards?

2. A follow up question. Would it then be possible to set the maximum power drain from the home battery? Lets say while charging the EV, it will use all available solar, and only XXX watts from the home battery? This so some reserve power is available for domestic use without having to use the grid.



michaelvh asked
motylu rolled back ·

17 Answers

Using SOC to control charging with Multiplus

What I have:

  • Multiplus 2 12/3000
  • Non Victron LiFePO4 bank
  • Non Victron battery monitor which sends SOC via NMEA2000

What I want to do is utilize the SOC information to control how the batteries are charged. Ideally, I could have the charger switch to 'OFF' when the batteries achieve a certain, programmable, SOC level. This is done with iPhone often times--when your battery gets to 80% SOC, the phone will often times stop charging it (depending on how you use the phone). I want to do something similar--have the Multiplus stop charging at, say, 80% SOC by default. Ideally this threshold would be something easy to change so that when I occasionally want to take advantage of the full capacity of the batteries, I can charge to 100% SOC. This will maximize battery life.

I suppose there are two main questions here:

  • Can the Multiplus interface with this non-Victron NMEA2000 SOC meter?
  • Regardless of that answer, if there is a compatible SOC meter on the Multiplus network (say a compatible Victron monitor), can that SOC information be used to stop or even impact the charger output? If so, how can it impact it?

I have seen the impact low SOC can have via the Multiplus, I'm wondering if anything can be done via Multiplus when a 'high' SOC is achieved.

boater asked
boater answered ·

3 Answers

SOC going up “percentage by percentage” possible?

Hi! I have a 24v 110ah lithium battery which supply my 220v appliances in my van. With this I have a SmartSolar Charger MPPT 75/15 from Victron which that handles the power from the solar panels on the roof and connects to the 24v lithium battery and lastly I have a SmartShunt 500A/50mV from Victron to be able to se the status of the lithium battery.

My issue is that even though I receive sun on the solar panels and the voltage is rising the SOC on the Smartshunt doesn’t change before synchronization, so I don’t know how much more capacity I have before I destroy the battery.

I’m wondering if there is a way to calibrate the Smartshunt so the percentage goes up “percentage by percentage” (e.g. 64%,65%,66%} or can I safely continue to use the electricity if the voltage is high enough (e.g. over 26v) even though the SOC says I’m going lower than 10-20%?

Thank you!

Best regards, Mikael

mike5fant asked
pwfarnell commented ·

3 Answers

ESS why does it use battery percentage SoC to determine charge stop point instead of voltage/current

I understand why using voltage to measure the state of a battery under load can be unreliable, since voltage drop is expected.

However, when charging under ESS I have an installation where charging stopped at 95% as programmed but this was actually a lower voltage, well below fully charged. This continued to get out of shape over a few days.

Why does ESS use SoC instead of voltage to determine when scheduled charging should stop? Whilst charging the absorption voltage is gradually reached in CC mode, then it switches to CV mode and the current gradually reduces as the battery reaches the voltage set.

So voltage would be a perfectly suitable means to determine when to stop scheduled charging. It would also be more reliable, as it would always reach a full charge, then set SoC indicator and then begin to discharge.

djdemond asked
wkirby answered ·

1 Answer

changing min SOC changes active SOC

Hi, if I cange the "min SOC" by the slider, the "active SOC" changes as well. That sounds funny to me, as the "active SOC" should be set by the BatteryLive funktion?

thanks Markus

marommel asked
marommel answered ·

2 Answers

Augmentation SOC Battery Life et charge depuis reseau


petite question suite à constat de la veille...

La base : MP2 + US500 en ESS AC coupled (CERBO, ET112,....).

Apres une journée de moindre ensoleillement, le SOC du battery life à augmenté de 10%, rien d'anormal, sauf qu'après l’arrêt de production des PV le système a tiré 10% du réseau pour remonter le SOC de la Pylontech à la nouvelle valeur.

Aujourd'hui il fait meilleur, donc j'injecte, plutôt dommage d'avoir du coup chargé la batterie la veille depuis le réseau.

Y'aurai t'il une astuce pour ne pas que ce phénomène arrive ?

Du genre avoir un SOC DELTA vis à vis du SOC battery Life qui bloquerai une recharge depuis le réseau, tant que le SOC batterie ne descend pas en dessous du SOC battery life - SOC DELTA ?

krystof69 asked

0 Answers

SOC on new install? Capacity seems off. 2 Battle Born Game changers all Victron hardware

When my System was installed I purchased one Battle Born Game changer, they wanted me to spend the night connected to a 50a shore power. In my RV. They had the shunt set to 270AH for the battery capacity. This was correct until I had them install a second Game changer. I changed the AH in the Smart Shunt myself to 540AH before the second BBGC was installed when the Battery was at 100% it said I had 10 days runtime. When the second battery was installed it still said 10 days? Even after I changed the setting in the shunt. I won't have the Dongle to get into the Multi plus II until later this week so I can't see if anything is not set right in the Inverter? Is the 10 day a max limit? Or could another setting be off? The installer did connect a laptop to the system while they were adding the second battery but didn't tell me what he did? I'm trying to get it setup as I want for my Boondocking needs . It's almost like they left everything default from the distributor. I found they but from Battle Born directly for batteries and Victron hardware. Battle Born says they pre program the inverters before shipping. Except for small adjustments like AH capacity etc. Thanks for the help. I would think my run Time should have doubled. After putting a second 270ah Lifepo batteries. The service from this place was not what I expected especially after dropping over $14000.00 on the system.

saboken asked
Alexandra commented ·

2 Answers

Battery monitor multiplus: SOC jumping and not accurate


Hi all

In my setups with a color control connected to a multiplus 12/2000, Victron AGM super cycle 230, MPPT 100/50, i noticed some werid changes in soc. While i only have inverter as load i use the multiplus build in battery monitor . No BMV or smart shunt connected because no need to.

Now and then my SOC seems to change.

While i can control the system by VRM sometimes i have to switch of the inverter to protect from battery drain. While it seems when i set the inverter to off i cant see voltage and amp-usage, i tebd to switch to "charger only" while above mentioned seems visible.

For example:

My battery SOC is 100 % while i charged by generator and solar panel. During midnight battery voltage is.12,9 volts and no amps drawn except multiplus standby amps, around 1 amp.

So SOC seems to be correct. I Leave multiplus on because i need power and slowly battery is draining because of ther is not too much sun and i use more power then solar can breng up.

Battery soc seems to be ok and calculations seem to be in order. After a few days battery SOC reacties 65 percent, Voltage around12,25. While i dont like to damage the batteries and i it is not completely nesacery i turn of inverter and switch to "charger only".

After one hour battery voltage has dropped a bit (also because solar power is less) to 12,15 and battery SOC jumped to 85 percents. 85 percents never matches 12,15 volts, even not without knowing amps drawing.

Build in battery monitor is setup correct with 230 Ah.

Above mentioned happens when i turn inverter off , or to charger only. It seems like build in battery monitor is confused after i switch off inverter?

Is there a solution to this problem?

Best regards and thanks in advance.

heinzie asked
Alexandra commented ·

0 Answers

Smartshunt inaccurate SOC

Hi Guys, Thanks for the great community and support, I have always found this forum to be extremely helpful.

I seem to have an issue with the Smartshunt State of charge in a recent installation.

I have 8x 90AH 12v Yuasa batteries in parallel totalling 720AH.

I set the minimum discharge floor to 60% as my usage is minimal and I would be surprised if I reach that below 80%.

Now the Smartshunt indicate total consumed AH to be -48.1AH and the SOC to be 97%. I think this is inaccurate

Now if I do my math ( I could be ignoring many factors)

according to the set discharge floor of 60% I have 40% usable.

40% of 720AH = 288AH

Expected SOC = 100% -( 48.1/288)x100) = 83.2%

and not 97%

I am confused. can you please help :) below are screeshots and battery specs.

Many thanks





vanlifer007 asked
slopz01 commented ·

4 Answers

Confusion on SmartShunt values

Hey all, I’ve recently installed my first Victron system on an RV. Components in question here are the MultiPlus II 2x120 24V, SmartShunt, and Cerbo GX. The way I’ve set everything up, I thought should be correct, but I’m getting some odd behavior. Because it’s an RV, there is a 12V DC system in addition to the MultiPlus outputs. I have 2 batteries wired to the battery side of the shunt, and system side of the shunt goes to the MultiPlus, DC system, and all the Victron components; that is to say, absolutely no load bypasses the shunt, it should see everything. Because of the DC loads, I have the Cerbo set to “has DC system”.

When the MultiPlus is off, it appears that the shunt registers DC loads as charging the battery, not drawing from it. The little dots on the overview graphic appear moving towards the battery, and the amperage readout on the battery shows positive while on the “DC system” amps show negative.

When the generator is running and the MultiPlus is charging the battery, it seems to mostly behave normally, but the DC system amp readout will bounce between positive and negative.

I’m not sure if this is the root cause or not, but the State of Charge readout is entirely inaccurate, too. I’ve just done my first trip with this system. I had the batteries fully charged before leaving, sync’d the shunt to 100%, and left for the trip. My first night, batteries completely died, to the point nothing would power on even briefly, the 24V battery bank was registering under 10V, yet the shunt still read 82% SoC. Throughout the rest of the trip, I had low batteries at various times, setting off the alarm on the MultiPlus, etc. And the shunt would read <20V while still showing 100% SoC. It also appears this is impacting charging, as the batteries were under 20V and yet the MultiPlus was showing the charging state as “float” within 10 minutes of starting the generator.

Needless to say, I’m rather confused. Any tips would be greatly appreciated!

EDIT: Pictures of installation for wiring purposed added below, thanks @Matthias Lange - DE



knissone asked
knissone commented ·

2 Answers

Powerassist in ESS system development

In an ESS system, the powerassist function is disabled by the ESS assistant.

In Belgium the government is going to charge a tax based on the peak power, besides the existing taxes on the amount of imported energy.

This will make the powerassist function of the Multiplus II or easysolar important.

Now we are dependent on integrators to add the powerassist software on a raspberry pi-based module that adds this function to the ESS.

I find it disappointing that Victron is not willing to integrate this function in the ESS assistant.

Is there really nobody in this community that is able to make this work? I am willing to pay a fee for that...

I have a 9kwh battery pack that is set on min SOC of 25%, to be able to deliver backup power when necessary, like an outage of the grid, or the grid voltage raising above the max allowed grid parameter, making the inverters disconnect from the grid.

But there are 2 situations I can think of, in which I want a deeper discharge of the battery.

  1. Powerassist: When the AC input grid power of the house exceeds 4KW, the battery should assist the grid with extra power, so that the input gridpower stays below 4kW. After the power demand in the house gets lower again, the battery may charge back to 25% SOC with low charging gridpower. By the way, Charging the battery with grid power must always keep the total import ac power below 4kW, which is not the case now when setting a higher SOC for instance... A button in the ESS control with a boost charge power would be handy though, when you want to charge the battery asap.
  2. Weather forecast-based deeper discharge: Nothing to do with powerassist. But the battery may discharge deeper in the evening, when the next day a lot of sun is predicted.

maartenvt asked
footswitch edited ·

3 Answers

Adding batteries to Mutliplus system

I have a Multi 5000/24 with ESS assistant.

4 x 250/80 Mppt connected to a bank of 2s 6p 12v 135aH batteries.

I also have a PV system on the roof that feeds into the multi to charge the batteries when we have excess solar. (I inherited this when I bought the house with a good feed in tariff)

The DC coupled battery are set not to feed in.

I would like to add another 12 batteries to this system.

I dont have BMV or smart shunt.

I understand that I need to reconfigure the multi with the new battery bank capacity but how does the multi know the % of SOC?

Would I be best to buy BMV.?

Many thanks


richie-gorrod asked
richie-gorrod answered ·

2 Answers

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