48v battery Image

48v battery

Charging 48V batteries from alternator


It's been some time now that I'm trying to find a solution for my next van installation.

I first came with this diagram with 2 victron 12V LifePo4 (24v): https://community.victronenergy.com/questions/65042/wiring-diagram-for-a-van-install-with-multiplus-ii.html

Now I would like to use the Pylontech 48 V batteries and a Multiplus II 48V/3000 for efficiency, price, form factor, ...

I searched for a 48V buck/boost around 50/100Amps and found nothing affordable and easily available. I do not want to install a second 48V alternator... At least not at first, I have a strong 250A 12V alternator.

The basic schematic would be as follow:

- A "small" inverter under the hood would allow to feed the Multiplus at the rear of the van without needing big wires (and losses).

- The inverter would be activated with a D+ signal to avoid discharging the start battery

- The installation would be very simple

- I could easily "tune" the amps drawn from the inverter with the AC input current limiter of the Multiplus

Is it possible ? do you see any problems with this kind of setup ?

Thanks !


Basic diagram without solar, Cerbo GX etc etc etc.




sebcbien asked
ciprian77 edited ·

5 Answers

46 volt battery pack instead of 48 volt posible ??


I have 24 lead-acid 2 volt, 1100 Ah batteries (48 Volt on 3 multiplus 48/5000 in paralel). Now 1 battery is worn out (it goes to 60 degrees as soon as charging starts).

My question:

Can the multiplus 48/5000 work with a 46V pack instead of 48V? Of course I will have to change absorption and float parameters and charging current limits but can it work? I would think it can since the "re-charge" lower limit is set at 42 volt now (the system starts charging from the grid at this level) and it all works fine. I realize that the use range will be reduced but like said, that isn't a big issue for me as such.

The alternative is to replace the old battery with a new one (about the same Ah) but that's not an ideal setup of course.

I don't mind loosing 2kWh of storage with only 23 instead of 24 batteries. In real life it's only 1 kWh anyway but I do mind replacing the complete battery pack because one battery fails ....

Any advise or remark is welcome.



jean-paul-1 asked
jean-paul-1 answered ·

3 Answers

Wiring help Truck with 48v system Questions

1. What fuses or breakers do i need and where?

2. Is the wiring right or does something need to be moved or added?

3. Shunts, Cerbo GX, etc needed?

4. Lynx 1000 needed?

5. This will be completely off grid

6. Is MPPT needed for EasySolar 2 GX?

7. Winch straight to battery or connected to paralleled Orion-Tr’s?


Updated down below



lpez210 asked
lpez210 edited ·

4 Answers

Mock-up comparable system to Sol-Ark 15k using Victron gear?

I'm researching systems for my whole-home grid-interactive solar+battery system. I've really enjoyed using other smaller Victron components and am trying to compose a system that would meet my needs. The reference I've found that can do these things is the new Sol-Ark 15k. Some capabilities:

- US-North America 120/240v (split-phase) grid interconnected.
- Controllable grid-interactive profiles (sell-back, peak shaving, etc).
- AC or DC coupled solar capability
- 48v Battery support (with interactivity to LiFePO4 BCMs)
- 100A+ load pass-through for normal operation
- Peak loads are around 8-10k (oven and/or stovetop).
- typical runtime household load is in the .5-4kw range.

Right now, I'm trying to piece together the inverter-charger aspect (setting aside solar for now) and not sure if I can do this with Victron gear.
Would I be able to use Quattro IIs for this? Would it make more sense to parallel inverters (to get more total passthrough amperage)? Does a parallel output going into an auto-transformer give me more capability (in a home with both 120 and 240v loads) than simply having each inverter drive one leg of the split phase?

Any other thoughts on an apples/apples comparison? Victron quality and support are attractive, but I ultimately need to build a system that meets my needs.

dgeist asked
wkirby commented ·

2 Answers

UPS functionality (split phase system)

Hi, I'm about to purchase a Sol-Ark 12k (4800w per leg) because of the all-in-one easy setup and Im certain it will resolved my situation. A friend stop me and suggested Victron because the Sol-Ark includes many features that I wont be using and will be paying extra for them.

I'm looking to have UPS functionality when the grid goes down for at least 24 hrs. I will use Homegrid 19.2 kWh stackable batteries that will be charged with the grid. Its for an apartment. No solar panels. I need 48v system for 120/240 with split phase power. Grid passthru is a must. Just one inverter. Im avoiding installing inverters in parallel because of a higher idle consumption and no solar power to compensate. The Sol-ark consumes 60w in idle. If any member could help will be greatly appreciated!

the loads in an outage:

  • refrigerator (inverter), led lights, wifi router, smart tv 55", cellphone and laptop charging and a mini split inverter a/c 18k btu (220v). The ac will be running for 5 hours or less.


charlie asked
lifeingalicia answered ·

1 Answer

Help with BMV settings

Hey guys,

I'm building a mini 48v system and needed help setting up the battery monitor. I'm new to Victron and solar. The photo included was taken just before installing the battery monitor. I've also posted a screenshot of the settings page for the monitor. The batteries are 12v Lithium from Dakota. Any advice would be greatly appreciated.



rbot asked
klim8skeptic answered ·

1 Answer

What's the lowest inverter operational DC input voltage of a 48V GX controlled ESS?

After several issues with a firmware update stopping my ESS working with a connected 40A sensor, I am finally getting the system work work as intended but one sticking issue is the voltage will not go below 41.2V, regardless to any settings I adjust.


41.2V happens to be the minimum inverter restart voltage set out by the ESS assistant and is the only thing I can think is the issue, but why does the inverter cut out at the voltage the inverter should be restarting at, if my assumption is correct. If the DC input low shut down is 37.2V, why does it show down at 41.2v?

To test my assumption, I have set every voltage I can adjust to its lowest setting so see if there is any change, and still no change. Dynamic cut-off all set to 36V & sustain set to 36V in the ESS


assistant. DC input shut-down set to 37.2V, DC input low restart set to 41.2V (the same voltage the inverter cuts out at???) My ideal minimum is 38V to maximise the useful energy within the battery whilst maintaining battery longevity.

I have even turned off Battery monitor in the remote console, as well as setting th minimum SOC to 0%, Ive turned off BatteryLife (set it to Optimized (without batterylife), DVCC off, Low battery voltage alarm disabled, still it will not go below 41.2V

Jason - UK asked
Jason - UK edited ·

1 Answer

2 house battery banks, a 12V and a 48V. Cerbo GX setup

How would I setup my Cerbo GX to see both my 48V house bank and my 12V house bank? I’m setting up a 48V bank with 800W of lithium to run 2 5000W inverters. While keeping my original 12V bank as is.

I’m using a lynx shunt and a VE.BUS BMS

paulcaetano asked
maloya commented ·

0 Answers

multiplus 48v wont turn on intermittent

We have an offgrid setup with 2 x multiplus 48/3000/35-16 configured in master and slave. BYD batteries, victron mppt charge controllers.and a color control box

We have an intermittent fault, where the inverters shut down. no error message, no alarms. just show state as off. The frustrating thing is that also intermittently the are other faults but none of which can be reproduced all of which result in loss of power to the house. one scenario is an overload showing when there is no overload, proved by turing off all the power circuits on the house fuse board.

Trhoughout trouble shooting the batteries are either full or charging so the inverters or the mppt are charging the bateries from PV but just not delivering 240v to main board

I have done a full system reset. shut the whole system down except the batteries to no avail. at one point we took the cover off the inverter didnt touch anything and the sytem came on and we had 240v. (with an electrician)

Justin asked
Justin answered ·

1 Answer

Multiplus 48V mit selbstbau LiIon Speicher / with DIY LiIon battery storage

English below.


Nachdem ich meinen Text fertig geschrieben hatte, ist mir aufgefallen, dass hier ja auch auf deutsch geschrieben wird. Naja, ich poste einfach beides, mehr Chance auf Erfolg :)

Ich plane eine große Batteriebank mit Packs aus 3P4S LiIon Batterien, jedes Pack hat sein eigenes BMS und Sicherungssystem. Spannung ist 14,4V, Ladespannung war mal 16,8V, wurde durchs BMS auf 16,4V reduziert und von uns nochmal auf 16V gesenkt, um die Lebensdauer der Packs zu erhöhen. Das habe ich mit einem 12V Multiplus und einem MPPT Laderegler umfangreich getestet, läuft prima, beide Geräte sind auf mindestens 16V einstellbar.

Ich haben wirklich viele von den Packs und es werden immer mehr, also will ich eine Batteriebank für einen ESS Heimspeicher realisieren, die mit drei 48V Multiplus geladen oder belastet werden kann. Dazu will ich Batteriekisten bauen, in denen immer 16 Packs zusammengeschaltet werden (extra Platine dafür designt), davon dann beliebig viele über Stromschienen zu großen Containerpaketen verbinden, und dann am Ende 4 dieser Pakete (gleich groß) in Reihe schalten.

So ergibt sich eine nominale Spannung von 57,6V, Ladespannung muss 64V sein. Die 48V Multiplus Geräte können das, bei 64V ist aber auch die Höchstgrenze erreicht. Unter anderem haben Elkos aber eine Grenze von 63V Spannung, ich bin daher nicht so sicher ob es eine gute Idee ist, an diese Grenze zu gehen. Die Alternative wären nur drei Containerpakete in Reihe, dann habe ich 43,2V nominale Spannung und 48V Ladespannung. Die Abschaltgrenze des Multis macht hier aber Probleme, unter 37,2V läßt sich diese nicht einstellen, das sind immer noch 3,1V pro Zelle.

Also sind vermutlich 4 Container Pakete in reihe die bessere Lösung. Was meint ihr?

Viele Grüße



I'm planning a large battery storage, build out of packs with 3P4S LiIon cells, each pack has its own protection and BMS. Nominal voltage is 14.4V, charging voltage is 16.8V reduced to 16.4V by BMS, reduced to 16v by me to extend battery life. Tested, works fine. I have got hundreds of these cells and I want to use them to build a off grid storage system with three Multiplus 48V, fed by PV or other sources.

To reach a high capacity and voltage, I am currently building containers with 16 packs, connected to a circuit board with a intelligence to check the health of the packs, specially designed for this project. Multiple of these containers will be connected together to a container pack and at the end we want to put four same-sized container packs in series to reach a nominal voltage about 57,6V.

The problem: the charging voltage should be 64V if we want to reach 16V per pack. Does that make sense? The 48V Multiplus' top carging voltage seems to be 64V (I checked out the demo) but I also have concerns, because 63V is the limit voltage of most capacitors.

Maybe I should reduce the complete storage design to 3 container packs in series? Then I will have 43,2V nominal voltage and 48 charging voltage. But in this case, what’s about the low voltage level? It is 37.2V, that is 3,1V per cell, when the multi switches off.

So I guess 4 container packs should be the better solution. What do you think?



Martin asked

0 Answers

DC/DC - 48v to 24v conversion + buffer battery?

I am in the process of spec'ing out the power electronics for a large sailboat. For various reasons, it will have a 48v LiFePo4 bank where the majority of charging sources come in, as well as the inverter/charger, and then a 24v buffer battery where most of the DC loads will draw from. It looks like the total 24v DC power usage will be around 10kwh per day, but with loads like electric winches or windlass potentially spiking temporarily to 3.6kw (~150A)

My first question is this - what is the proper way to handle this conversion? The only 48/24v dc/dc converters I see on the site are the 'dumb' Orion DC/DC chargers that go up to 400W. It looks like we'll need about 500W/hr of charging to keep up with demands, and an extra converter for redundancy (absolutely cannot have this fail at sea!) So it looks like 3 x Orion 48/24v converters in parallel?

Secondly - the buffer battery will be a Victron 24v 200ah LiFePo4 smart battery. The DC/DC converters seem to be configured to just output a steady voltage. Does this buffer battery need to be supplied with a 'smart' charger to give it exactly the right voltage to fully charge, or can the converters be set to a safe voltage and just keep it mostly charged?

hoeken asked
bathnm answered ·

6 Answers

Multiplus in ESS mode aansluiten op Belgisch net voor thuisbatterij.


Ik heb thuis een multiplus II GX aangesloten op het Net met een 10Kw lithium batterij.

Alles in mooi aangesloten zoals het in de manual beschreven staat en het systeem werkt ook gewoon perfect, Maar nu is de keuring langs geweest om het systeem te keuren en dat wilde hij niet doen omdat de omvormer in serie was aangesloten met het electriciteitsnet en niet in parallel. (Ik vertelde hem dat dit systeem enkel maar in serie kan worden aangesloten en dat alle meet apparatuur vanbinnen in de multiplus aanwezig is, en dat dit toestel aan alle veiligheids voorzieningen voldoet en gekeurd is door Synergrid belgie)

Kan iemand mij helpen met info of voorbeelden van iemand anders die dit ook zo gedaan heeft thuis, zodat ik dit kan voorleggen aan de keurder? Of heb ik zelf iets over het hoofd gezien?

In bijlage de schets van hoe het is aangesloten:



Met vriendelijke groeten


aaroncloet asked
kallenr edited ·

17 Answers

48v system off grid, solar controller question. (why only pwm ?)


I,m looking for a 48v system to build a off grid system in the future. 48v seems to me the easiest as this uses much thinner cables than a 12 or 24v system. However, when browsing for a 48v solar controller I only see pwm controllers and 2 mppt,s but those are quitte expensive. Is there a reason why there aren`t many mppt 48v controllers and so much pwm controllers ?

leverg asked
Alexandra edited ·

2 Answers

Lovato P2MB Double Pole MCB (P2MB2PC100) for Pylontech 48V isolation


Like a lot of people I am looking for a solution to the issue of isolating PylonTech 48V battery stacks. Looking on the victron videos on YouTube they show the Blue Sea 6006 or 9003 isolators with PylonTech, which while they are only rated to 48V DC I assume they are acceptable as they are shown in the official videos (I read somewhere they were actually tested to 72V).

While browsing I came across the Lovato P2MB Double Pole MCB C Curve 100A (P2MB2PC100) which based on the specifications will do 60V DC at 100 Amp. This is below the rated current for the PylonTech cables (120A) so would seem a good fit.

My plan is to have 6 stacks of 2 US3000C battery modules (all connected via the control cable to a Cerbo GX), with a positive and a negative cable to each pair (so 6 sets of cables going via the breakers to a pair of lynx power in modules and then to a lync distributor for connection to the inverter and mppts). Each pair of modules would go via an MCB (6 in total) so in the event of a fault I can isolate just that pair of modules and maintain the rest of my capacity.

With the solar and 8Kva multiplus-ii, peak charge current would be 48V 240Amp which would be split over the 6 sets of batteries (40A per cable) with the current draw from the inverter being <180Amp again split over the batteries (30A per cable).


Graham Walmsley asked

0 Answers

Idc Invert much higher than IOut?

Hey guys I'm pretty new to all of this- but it seems wrong that I'm getting a reading of 95 amps as my Idc invert but only 20.2 amps as my IOut. I would've figured those two would be closely matched.

So when calculating how many hours I should be getting out of my battery should I be using the 95 number or the 20 number? And if those shouldn't be so different, how would you trouble shoot that?

ggk1 asked
ggk1 answered ·

2 Answers


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