48v battery

I have 2 24v batteries connected in series for a 48v system but one of the 24v is getting more charged than the other. Currently I have 2 150/35 MPPT controllers in parallel charging the 48v battery and it's monitored by a BMV-712 which needs to be the only thing connected directly to the negative 48v terminal to track the current in & out. The negative terminals for the solar panels & the MPPT controllers (both for solar in and the other for battery out) are connected to the chassis (to reduce loss from heat/save wiring, this is in a motorhome - side question: is this helping or hurting?).

1. If I connect the +/- terminals of one 24v battery directly to the +/- of one MPPT controller (and do this to the other 24v battery too), will this work or short? If so, how is the + terminal in the middle (of the 48v set) connected to the - of the other battery protected against a short when that - terminal is connected to the - of the MPPT controller?
2. Should I use a battery balancer for this issue instead?
3. Whether balancing with a balancer or using the MPPT controllers on the individual 24v batteries, how will the BMV accurately track current unless it's the only thing between the battery and ground?

Good Day

We have come across this issue on our one Victron Installation. The loads that gets used is less than what the battery reports it is giving out.

Is this something to worry about?

how can this be fixed?

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Hi everyone,

I am a power engineering student and I am looking into the inverter model Quarto 48V 10000VA 140A 230V AC quarto. Its used within a project by NPG called Silent Power. I am new to this so I am tying to get as much information to understand the inverter. I've looked on this site but I am finding it difficult to pick out the correct relevant manuals and technical information. Could anyone please help.

Kind regards,

Dan

Hello

Being new here and after searching the forum, I didn't find an answer and I am looking for some help. Thank you very much for your time and answers.

I am planning to wire in serial, 4 Hankook 12V - 65Ah to get to 48V in order to drive through an Alltrax SR 48300 controller a DC Motenergy ME0909 Motor ( 48V - 100 Amps ).
1) Is it a mandatory to use Battery Balancers (like BMV-702 or 712 ) in a serial AGM Battery Bank ( 4 x 12V ) as I have read somewhere that AGM batteries don’t need equalization ?
2 ) I understand these batteries balancers work when charging but do they work also when running the motor and therefore discharging the batteries ?
3) What is the best way and easy way to charge these batteries ? Is it by charging them one by one with for example a Blue Smart IP22 ( 12V ) or directly with a 48V charger like a MEC ( 48V Charger )

Thanks again

Hello,

I'm planning an off-grid installation with four solar panels, a SmartSolar MPPT 100/20 (48V) and a MultiPlus II 48/3000/35-32.

I'm wondering how I could monitor my system and I see (at least) two options:

1) Raspberry py

In this case I'd need to get:

• UTP cable + MK3-USB interface to connect MP II to the Raspy
• VE.direct cable + VE.direct to USB interface to connect the MPPT to the Raspy

Is that right? Or can I connect the MPPT directly to the MP II? In the latter case I don't need to buy VE.direct to USB interface

2) MultiPlus-II GX 48/3000/35-32

In this case I'd need to get only:

• VE.direct cable from MPPT to MP II GX.

Is that right? As MP II GX has only one VE.direct port, is there any other way to connect MPPTs to it, in case I will expand my system?

Do I really need MK3-USB interface with MP II GX? What's the purpose of USB port??

Which option do you suggest?

Sorry for the large amount of questions and thanks in advance for helping me to have clear ideas :-)

Matteo

Hello all,

I'm new here sorry if this question is redundant.

I'm building an offgrid system. I will NOT be selling power to the grid. I want to get an inverter/charger that's good enough so i can eventually add more panels and more batteries without having to get new ones and re-wiring all the time.

I was thinking on going with 2 3648a outback prewire inverters but I like the apps of Victron and outback is not available here.

1. I want a 10kw system
2. 48v to 60v system.
3. 10x 500 watts panels from china ( another 10 later)
4. 3 x Tesla smart lithium ion batteries ( 57v 2.5kwh) , I plan to get 11 of these.
5. Victron charger controller and inverter

Questions are:

1) Which inverter/s should i get?

2) 250 charge controller will be enough?

3) Quattro or Multiplus?

4) Will the Victron inverter work well with tesla smart batteries?

We've just installed a MultiPlus 3000/48 to run a pump Pedrollo 4SR6m/13 (https://www.arrosage-distribution.fr/pompe-4-sr-6m-13-pedrollo-6198.html). The pump is rated at 1500W, but seems to pull more like 2300W.

However the Color Control indicates that we're pulling 2877W from the battery, but only supplying 2277W to the pump. There is also a 148W dc load (the inverter?) So where is the 450W going?

Of course at 2900W the Multiplus gives me a overload warning, and after a half hour shuts off with an overtemp warning on the Color Control.

The only solution I've come up with for the moment is changing the Multiplus 3kw for a 5kW, but would hope to find another solution.

Hi,

Does anyone know if Victron inverter/chargers are compatible with the Apollion Cube?

or

Is anyone using an Apollion Cube as a storage module?

Dear community,

I wish to primarily charge the BYD 13.8 kWh (288 Ah) through 2 x MPPT solar chargers. The Multiplus 48/1200/13 is primarily used to power a constant (and max.) load of 700 Watts. It will be grid-connected and it is there to back up charge the BYD B-Box in case of bad weather days.

Question: is the 48/1200/13 with 13 Amp charging power sufficient for this purpose?

and: it has a transfer switch of 16 Amp, so for example, if the battery is empty, and the load is on at 700 watts (approx. 3 Amps at 230V), will the multiplus transfer the full load requirement and charge the battery at max capacity of 13 Amps simultaneously?

Or is it wise to go the Multiplus 48/3000/35?

Hope I was able to make myself clear!

Thanks very much!

Best regards,

Fabian

The system consists of two inverters ( Quattro and Fronius), batteries and PV panel. previously, the system was connected to a 50 Hz grid. Now I would like to connect it to a 60 Hz grid. Should I connect the inverters to the 60 Hz grid first and then change the frequency settings using VRE Config.? .I need the sequence to change the frequency of the inverter( 50Hz to 60Hz).

Hi all,

I have a fully operational new system but currently without monitoring.

Multiplus 2 48v, BMV 700, automation system

The bmv has a 4 pin serial port on the rear.

5v, Rx, Tx, Gnd.

I have the victron cable 9pin rs232 to the BMV

In the said cable there is circuitry in the 9 pin end, the other end is sealed. see photo.

[image]

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I was able to find some lithium batteries that are configured 8 series and I have about 10 of them. My question is can I use the Multiplus 48v which technically states it can handle 38 - 66v dc. I am interested in higher voltage like 16s. Has anyone done similar thing . I would have to charge my batteries less than full (4.2) to stay under 66v which is fine with me. I love Victron products now it’s time to go big.. thank you all again. All your suggestions are appreciated

I am aiming for higher voltage like 16s2p to save wire cost and efficiency

Hello,

I have a remote off grid site, running a Raspberry Pi for monitoring and it is supplied by a 48Volt Battery Bank. Raspberry Pi + 4G Modem consuming together about 4W continuous power. The current measurement resolution shown in Venus is 100mA leading to a 5W resolution on a 48V battery bank. If no load is active except the RPi, I have a flipping DC consumption monitored and shown in Venus. So the VRM charts look like:

[image]

With a fully charged battery it gets logically worse, leading to zero consumption for longer periods:

[image]

Is there a way to improve this?

Thanks,

Markus

hi , looking for ideas . i have a 72v battery bank,36 x 2v cells and a 48v multiplus (one) and want to charge the left over 24v battery bank, i see the multiplus has aux battery charging terminals. is there a more efficient way than putting in a 48v to 24v dropper?

@Guy Stewart (Victron Energy Staff)