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Auxiliary charging

Hello all.

I'm going to have to bite the bullet and buy lithium, as my Hoppecke FLAs have died after just 8 years.

I say died, but they still function. They just lose voltage very rapidly.

I was thinking of leaving the FLAs where they are and keeping them trickle charged "just in case".

It's a 48v system.

Has anybody here done this?

PS: It's a Quattro 48/8000

Paul Carmichael asked
Paul Carmichael commented ·

0 Answers

Constant charge for Smart Lithium

Hi guys,

I have a boat with the Victron smart lithium batteries 3 x 200ah and while the boat is not being used it has a constant load of around 3amps to run monitoring systems, WIFI etc. I want to keep all this on as I want to remotely monitor the boat.

I am really trying to keep the batteries between 40% and 70% to extend their lives while the boat is sitting there but I need to keep the boat connected to shore power as the solar is not enough to hold the charge. I am using the DVCC fuction on the cerbo for the multiplus to limit the maximum charge current usually at around 4-6amps to keep the batteries between 40 and 70%. I adjust this manually. Just before I use the boat I will up the charge current to 120amps to bring them upto 100%.

I just have a few questions:

1. Do you think this is a good way to exend the life of the batteries

2. Is there a better way to float the batteries at aroud 60% without turning everything off? I was thinking of putting in a relay for 240v on the Cerbo gx in generator mode so it will connect the 230v when the charge is low and disconnect when the charge level is higher.

3. Will the constant charge harm the batteries even if the current is lowered. It seems that the voltage is also lower when you reduce the current via DVCC. Would you recommend setting a lower voltage for doing this? If so what would it be?

Thanks in advance Victron experts

chris-job asked
snoobler answered ·

1 Answer

Strange behaviour: Battery status

Got my new system running, main components:

MP5000, JK BMS, 10KW Battery Li ION (NOT lifepo4). Excess energy fed to the grid.

From time to time the following happens:

Battery status: nearly full (60v)

PV production low, ca. 500 watts

AC Loads go up to about 2500 W for some seconds only (no big consumer active in the household...). Grid consumption goes up too, of course.

Battery goes down to 51V.

Battery alarm goes on.

Then during about 10 seconds the battery goes up volt by volt back to 60v.

What could be the reason for this?

And: why is there an alarm at 51 volt? I didnt set it anywhere to this point.

Thanks !

alexch asked
Alexandra answered ·

1 Answer

BlueSmart IP67 on a VW T4 California


I intend to replace my burned original charger in my VW T4 California (Westfalia 1994) with a Victron IP67.
On the Westfalia charger, there is a secondary ouput line (around 12v) that feed the electronic unit of the vehicle to display the plug symbol.
I wonder if I can use the optionnal Si output of the Victron to feed the unit... I think it's ok for the voltage, but what about the current intensity ? I would like to avoid burning the central unit...

If someone knows, thank you in advance !

reno asked
reno answered ·

1 Answer

Battery charger under unstable AC input

Hello, I need to find a battery charger able to deal with an AC input that is quite unstable in terms of voltage and/or frequency - it comes from an old hydraulic turbine that feeds a very small village. Now with low water flow its output is irregular. So, the question is, in this situation which one is the best battery charger for flooded lead-acid batteries, and which one would be the best for LiFePO4 batteries. Thank you very much!

oriol asked
klim8skeptic commented ·

0 Answers

No DC current through new Quattro

I have a new Quattro that has 0 DC amps at all times. AC output only works when I have an AC input (generator connected to AC1). It detects the batteries and their voltage, but will not charge or pull power from them. It says inverting when there's no AC input, but then says there's no AC load to power. I've checked all the current settings in VE Connect & Configure, nothing seems to make a difference. Recommendations on settings to check? Or might it be a mechanical failure?


System when there's no AC input

rebecca-bauman asked
Alexandra commented ·

0 Answers

Solar power being wasted.

We are generating 11kw on solar, using 4.4kw but only charging at 900w. The charge rate varies but we seem to be loosing a lot of generated energy. We have 4x BYD batteries, Victron CerboGX, 4x Fronius Primo solar inverters and 2x Victron Quattro 48/10000/140.

Our connection to the grid is disconnected; if we connect to the grid then we export most of the power rather than charge the batteries.

bill-wilson asked
bill-wilson answered ·

2 Answers

Correct setup for two 12V 400Ah LiFePo4 Batteries in Parallel

I need help setting up my new Victron Equipment for charging. I want to be able to charge from solar and shore power. So at the bottom of this email are my two simple questions.

Victron Equipment:

  1. MultiPlus 12V, 3000VA, 120A
  2. MPPT 150/70-Tr SmartSolar charge controller
  3. MPPT 150/70-Tr SmartSolar charge controller
  4. Orion 12/12-30 DC-DC charger
  5. Cerbo GX
  6. LYNX Distributer
  7. SmartShunt 500A/50mV

Solar Panel Specs: I have two sets of two panels in series each panel is 410W

The solar panel specs are:

four 410Wh Solar Panels - two 410Wh on the RV roof plus two 410Wh deployable on ground (1640W total) (they are ~ 68" x 45")

Each Panels Specs

In Series

Maximum Power (Pmax) 410W



Maximum Power Voltage (Vmp) 31.35



Maximum Power Current (Imp) 13.08



Open-circuit Voltage (Voc) 37.12



Short-circuit Current (Isc) 13.96

Module Efficiency STC (%) 20.97

I have two new 12V 400Ah LiFePo4 Batteries I will be using in parallel (after I charge each up equally to full voltage individually) in My RV. The Battery Charging parameters from the manufacturer are:

Bulk | Absorption: For your Bulk | Absorption stage the ideal voltage is between 14.2V & 14.6. For full charge and balance the absorption mode should be set to last for at least 20 minutes per battery for multiple batteries in parallel.

Float: LiFePo4 batteries do not need a float stage for charging but a float voltage 13.4V and 13.8V can be used when connected to shore power.

Equalization: Equalization is not recommended for these batteries. Most chargers will allow you to shut this feature off or use a setting that does not use equalization. If you cannot turn off this mode then you will need to adjust the equalization voltage <14.6V.

Temperature Compensation: Temperature compensation is i]not needed for these batteries and in some cases may trigger the built in BMS to go into protect mode. For this reason, we recommend that the temperature compensation be shut off or set to 0.

Built in BMS Basic Features are:

High Voltage: >14.6V. If the individual cell voltage exceeds 3.2V during charging the BMS will prevent a charge current from continuing. Discharge is always allowed under this condition.

Low Voltage: <8.8V. If an individual cell falls below 2.2V during discharge, the BMS will prevent further discharge. Charge current is always allowed under this condition.

High Temperature: >65C. The BMS will prevent both Charging and Discharging during this condition.

High Current: The BMS allows a constant current of 100A (+/- 5%), 260A (+/- 10%) for 5 Seconds.

Passive Balancing: A passive balancing process is activated by the BMS at the top of each charge cycle when the battery voltage exceeds 14.6V ensuring that all cells remain at same SOC.

I have the Victron Equipment on a bench and all wired up to the Solar and Batteries. Just need to configure it. I can use the Android app now too.


1) What is the proper setup configuration to charge the batteries from the MPPT's?

2) What is the proper setup configuration to charge the batteries from the MultiPlus from Shore Power?

Thanks for any and all help.

jerrykco asked
jerrykco answered ·

3 Answers

What to do with my leftovers... Should I cascade them ?

I have had my pair of Multiplus II 48/5000 (240V) running in Parallel for a couple of weeks now, and they are working fine. (other than a dodgy fan in one of them)


but I have a load of parts leftover !

when I started my Victron solar journey, I bought loads of stuff that I thought I'd need and then bought other stuff that was 'better' (differant)

So. I have four Epoch 12v 105Ah LiFePO4 batteries (that I was going to connect as a 48V pack)
a 500A SmartShunt, a SmartSolar MPPT 150/35, a heavy duty DC isolator (Icu 85kA)
loads of 50mm2 and 75mm2 cables and Lugs.
A Raspberry Pi with Venus OS and a load of USB to VE Direct DIY Cables, set up and ready to go.

I can't hook the 4 Epoch batteries up to my main (BYD battery) system.
But I could buy a small Multiplus 48/1600/20 and cascade them ?
Thinking of setting up a second "separate" system that just powers my office (using about 2kW per day)
that part is not that complicated

is how to set up charging and pass-thru

I don't really want to set up more solar... so would like to only charge the 4 Epoch batteries, from the main system, once the BYD batteries are full, and we have excess solar.
and would like the Multiplus 48/1600/20 to go into passthru if the 4 Epoch batteries are low

And I just can't work out the best way to do it.

I was thinking of using a Shelly 4 Pro to switch power to the Multiplus 48/1600/20 once the main batterys were full, but then how would I work the passthru, if both sets of batteries were low.

and how would I stop the Multiplus 48/1600/20 from drawing power from the BYD battery to charge the 4 Epoch batteries (that would just be a waste)

there must be a way... anyone :)

thanks in advance

iammotorhomeless asked
matt1309 edited ·

1 Answer

Replacement charger

I am looking to replace my cristec 12v 60a charger with equivalent victron which victron charger would be the most economical ?

Currently running 5 175w victton solar panels through 2 mppt

Also have bvm 712 monitor and dc to dc isolater.

Also installed at the same time a galvanic isolater

Our cristec charger was fried after installing the above

We also have a generators on board.

Need charger for charging domestic house bank when plugged into shore or from generator

Sorry not very savvy about this stuff not too sure what other information is needed

chez-nous asked
klim8skeptic commented ·

2 Answers

Mobile off-grid design Challenge

Dear VE Community,

I am seeking your expert advice on a custom project that I am currently designing for a trailer application. I would appreciate your feedback on whether the design meets the requirements or if I need to make any changes.

Here are the major specifications of the system:


  • The system must be able to receive power from both one AC source (such as grid or diesel generator) and DC source (such as solar panels).
  • The system will primarily operate in off-grid mode, with "Storage" batteries used as the main power supply.


  • The system includes two "load" batteries rated at 24V and 22Ah each, which should receive a constant current between 10A and 20A to be replenished.
  • Additionally, some DC loads and AC loads needs to be fed with power. These loads are on demand and not constant baseline.

Please note that the "load" batteries are not intended to reverse energy back to the system. Instead, they will be discharged elsewhere. Think of the system as a continuous battery charger on wheels!

My current preferred design uses a Victron Multiplus II 24/3000 combined with 2x Pylontech UP2500 and a Lynx Distributor. Two DC-DC 24/24 chargers would be installed between the Lynx Distributor and the "load" batteries to charge them. According to my calculations, I should be able to replenish the "load" batteries around 4-5 times each.

I have attached a high-level schematic of the system for reference:


I would greatly appreciate your input on the feasibility of this design to fulfill its intended purpose and any potential improvements you may suggest. Any suggestions and tips before I move forward with more detailed design would be invaluable.

Thank you in advance for your assistance!

eugenioschloss asked
kevgermany commented ·

0 Answers

EasySolar-II: MPPT Low Charge Voltage

Hello colleagues. Half a year ago I ran into a problem that I have now managed to solve. I want to leave this here, maybe it will be useful to someone. It would also be great to get official comments from Victron in order to better understand the reasons for what happened.

So, this is a house in the forest, far from civilization. Autonomous system with EasySolar-II GX 3000 with built-in MPPT 250/70 + four AGM batteries of 130 Ah + battery monitor BMV-700 + PV modules 1980 Wp. The system was put into operation at the beginning of 2021.


The system worked great, but two years later a client complained to me that after sunset the system turned off too quickly due to low battery voltage. At first I thought the batteries were dying. But it turned out that even on a sunny day and with minimal consumption, SOC rarely reached 100%, since something was limiting the charge much earlier. As soon as the water heater was turned on, the PV power immediately increased to normal values.

Having studied the charts in detail in the Advanced section, I found that the built-in MPPT incorrectly reads the battery voltage, overestimating it.

Fortunately, there are three devices in the system that measure battery voltage: MPPT, VE.Bus and BMV. The VE.Bus and BMV readings are completely the same, and the MPPT readings are 2.5-3 volts higher. If this only happened during the day, when the MPPT is a generator, one would think that there is a problem in the wiring that is causing the voltage drop. But the MPPT shows a higher battery voltage even at night, which means it's not the wiring.


As a result, the MPPT "thought" it was supplying the correct voltage to the batteries, when in fact it was almost 3 volts lower. From this, the batteries were chronically undercharged. I checked all the settings, everything was correct there. Then I started looking on the charts for the moment when this problem first appeared. It turned out that the minimum difference in readings began about 6 months before the client complained to me about the strange operation of the system. Since then, this difference in the measured voltages has gradually increased, reaching 2.5-3 volts.

The solar controller built into the EasySolar-II is connected to the batteries not directly, but via a board with electronic components. Something must have happened there. I updated the firmware of all system components to the latest versions, but nothing has changed.

Then I created the E-RMA. Victron told me to remotely disconnect the voltage sensor in the inverter as a test, but that didn't help. The case was declared under warranty and I could send the EasySolar to Victron for repair.

The object is far from us, and all transport costs with dismantling and installation would cost our client at least 300 euros, which did not inspire him at all. In addition, we could not leave the client without electricity, because the system is autonomous. So it was necessary to provide a replacement EasySolar, which at that time we did not have.

And now we have a replacement EasySolar, and before organizing the repair, I decided to try to solve the problem remotely again. By this time, the new version of Venus OS 3.00 had just arrived, but the update did not change the situation. Then I reset MPPT to factory settings and set it up again, but that didn't help either, as did rebooting the entire system multiple times. I did many other strange things, even activated the equalization in the MPPT settings for a few seconds, hoping to somehow stir up the MPPT and reset its error: the battery voltage jumped, but the difference was again almost 3 volts.

Then I had the idea to just change the charging voltage settings in the MPPT configuration so that the actual values on the battery would be correct, but this was not a desirable option, because over time the difference can become even greater. And I don't want fake data from MPPT on the charts.

The last thing I decided to try was to take away the MPPT's ability to make decisions on its own by switching it to "External control" mode, and for this you need to install an ESS assistant, which, in general, is not intended for off-grid systems. As soon as I installed the ESS assistant, the problem was immediately solved.


It's hard for me to say why this happened. I can only assume that some components on the board through which the built-in MPPT is connected to the battery did not work properly, but these components do not affect the operation of the MPPT in "External control" mode. Maybe, of course, the problem is in the MPPT itself, but I have never encountered something like this when I installed MPPT separately. It would be interesting to know the views of fellow installers and Victron employees on this matter.

romarub asked
romarub commented ·

1 Answer

Multiplus charge issue with Ultimatron lithium battery

Hi, I have a Victron MultiPlus (12/500/20 model), and an Ultimatron Lithium battery (it has a integrated BMS). When I connect the Multiplus AC IN to charge the battery, it only charges at 1A or even less than that (battery is at 38%). After some time, it seems to not charge anymore at all (and the "charge" led blinks). I have used the USB MK3 adapter to connect to my computer and configure the multiplus for a lithium battery, but it does not seem to change anything. Do you have any idea on what could be wrong ?

Thanks for your help,


dyravinir asked
dyravinir commented ·

1 Answer

Does blue smart IP22 charger have separate settings for Lithium-Ion and LiFePO4 batteries

Victron Energy Blue Smart IP22 12-Volt 30 amp 120VAC, Single Output Battery Charger NEMA 5-15, Bluetooth

rgrantp asked
klim8skeptic answered ·

1 Answer

How to charge a 48V system from a 12V vehicle alternator

Hey everyone, First post on here!

We're just in the middle of setting up our Victron system and want to use a 48v system (due to cable sizing and efficiency) in our overlander which has a 12v alternator.

My question is, can the Victron batteries be charged in parallel (i.e each batter individually charged) but drawn from in series?

If so are there Victron products or suggestions on the best way to achieve this setup, there will at some point also be some solar power introduced too, so if that could be kept in mind it would be great!

Any advice/suggestions gratefully appreciated!


james-yardley asked
ian-norton rolled back ·

7 Answers


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