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Using a smartShunt to parallel 2 batteries?

I have 2 48v server rack batteries (eg4) which I want to wire in parallel to a smartshunt. In the eg4 manual it says not to jumper the batteries in parallel, rather use a properly rated busbar to connect them in parallel to avoid large currents and overheating in the end wires, so I want to try to avoid diagonal method of paralleling.

So my question is this:

In my case because its only 2 batteries, can I just connect the 2 negative wires to the battery end of the smartShunt? Its not 4 batteries which would warrant a whole busbar, really just 2 5 awg wires connected directly to the shunt, using the shunt as a "post"...

I know its kindof "abuse" but is it really necessary for me to add a busbar?

And then while I'm at it, I have the same question for the positive side... Can I just attach the 2 positive wires directly to a t class fuse?

In the continuation of the system I will have of course a lynx distributor, I'm just wondering if I can avoid adding 2 possibly unnecessary busbars to my system...

ori-haberman asked
ori-haberman commented ·

1 Answer

Which battery cabling to prefer?

Hey there,

I've already done a couple of installations which all runs fine. I always stick to the "Unlimited wiring" guide for best DC / AC cabling. Normally there is plenty of space to have one big battery bank with equal DC lengths (f.e. multiple Pylontech + Victron Lynx).

Now I will install a bigger bank on a boat (catamaran) and would like to know which way would be best. Both options have pros & cons, maybe there is a third option I don't have in mind.

There is a bit space in each hull and in the middle of the catamaran. Which makes me have 4 spaces for the batteries.

Each battery pack will have it's own BMS. In total the battery will consist of 144x 280Ah Lifepo cells.

Keep in mind that in the schematic are no fuses and kill switches. Surely they will be add in the installation.

The normal use during driving will most likely draw only 2-4 kW in total. But the system has to be capable of maintaining 6kW to both engines over a couple of hours if necessary.

Left Option like Page 19 at wiring unlimited "Diagonally":


- should make equal current on all banks

- only one battery monitor (shunt)


- horrible long cables, about 28m for each + and - cable to the bus bar. Another 9m for each engine (just 125A)

- a couple of volts drop even with 120mm2 cable

Right Option like Page 19 at wiring unlimited "Busbars":

In this case the cable itself is the busbar.


- shorter cables


- 4 batteries in Victron System (not a problem at all, monitoring will be through (modified) MarineMFD App on a Raymarine MFD)

- unequal usage of batteries
- batteries in hulls will be discharged faster and get less charge than center batteries!?

I think (hope) last point shouldn't be a problem when laying on anchor the banks should be equalling themself, right?

Anyone tested this?

I also had the idea to build real separate banks and use Orion 48/48 to charge the banks for the engines. But the Orions are really getting only near 90% efficiency and I think that is a bit to much inefficient as the engines will be the biggest consumers.



klandos asked
klandos commented ·

0 Answers

DC consumer fuses/breaker

The Wiring Unlimited guide says that all DC consumers (load) need an individual fuse. I have about 10 DC consumers that I was planning on splitting into 3 groups and have an appropriate sized breaker for each of the 3 groups. Is this sufficient, or do I still need fuses on all 10 individual consumers? Also, is there any disadvantage to have the individual fuse right after the positive comes off the positive bus bar than directly before the load (consideration for changing blown fuses)?

adrianp105 asked
christern answered ·

2 Answers

One Bus Bar set for Multiple Arrays and Controllers?

Hi all, I've designed my system to have three (3) PV arrays (one east facing, one west, and one south - all 18v max @ 100w) - the eccentricities of the area required this odd combination to achieve the desired output. I have three SmartSolar MPPT 75/15s that I intend to connect to a Cerbo GX with VE.Direct cables. It is my understanding that I need the Cerbo with arrays facing different orientations and drastically different performance throughout the day. All of my loads will be 12v DC, so I will not be using an inverter. I had initially planned on doing a separate busbar out of the load side of each controller, then connecting a group of loads to each of those busbars. But I have seen a few schematics where multiple arrays have one positive and one negative bus bar for the entire system. I want to take advantage of the controller load output to regulate the load for sensitive electronics. Is there anything wrong with doing separate busbars for the load out on each controller or am I missing an important feature/benefit to combining the busbars. Thanks in advance.

adrianp105 asked
adrianp105 commented ·

3 Answers

Battery connection to Lynx Distributor

For organizational purposes, I'm thinking of running my positive and negative battery cables to opposite ends of my Lynx Distributor. I can run them to the same side if necessary, but the way things are set up and given where the battery terminals are in relation to the Lynx, it would be easiest, most organized, and shortest cable runs to have the positive attached to one end, and the negative to the other.

I'm thinking this should be totally fine, they are essentially two separate busbars after all. Does anyone see an issue with this setup? Positive will obviously be fused at the battery and have a switch before the distributor, negative will have smartshunt.

Thanks much

igvan asked
Trevor Bird answered ·

6 Answers

Clarity on BMV-712 connectivity parallel battery bank

Hello Everyone,

sorry if this question is somewhat amateur however could somebody please check my wiring intentions regarding BMV-712 Smart?

I have two 12 V | C20 | 200 Ah lead acid batteries connected in parallel via a busbar (cables of equal length to balance resistance).

If I've understood correctly, the shunt 'Battery -In' should connect to the negative busbar whilst B1 should connect to the positive busbar.

The battery capacity should be set to 400 Ah in the App.

If my understanding is correct B2 (Aux) can't be used to measure the Midpoint as my battery bank is 12 V; could however the temperature probe could be used to measure the batteries via the positive busbar?

Below is a sketch of my intended set-up.

Best regards


bazil asked
bazil answered ·

5 Answers

Using Victron Power In with Pylontech batteries.

Hi everyone

I have a Deye 12kw inverter that uses 10x Pylontech 3000C batteries and is connected with a 250A fused disconnect. Because of the limitations of the Pylontech battery cables I want to double my charge rate to 200A. Can I use the Victron Power In as a busbar without fuses using the fused disconnect that I already have or is it better to remove the fused disconnect and modify the Power In to take fuses or buy something like the Lynx Distributor?


George asked

0 Answers

Fuse blows when Lynx Dist powered. Why?!

When I turn on (close) the battery disconnect to power the lynx distributor the 125A 48V (Victron) fuse blows on the battery connection In the Lynx. The only thing connected to the bus bars on the lynx distributor distributor is the inverter and the batteries. I checked and rechecked polarity and everything is correct. The 48v batteries are reading 53V. The inverter is off. A smart shunt if correctly installed between the bat negative and the negative bus bar on the distributor. The shunt bat plus and aux cables are connected to the bat pos terminal and the mid point positive. As far as I can tell everything is connected properly and secure and there is no reverse polarity. What would cause the fuse to blow When the Disconnect is closed (on) and the distributor is powered?

duswami asked
duswami commented ·

1 Answer

Grounding with the Lynx Distributor

Can the Lynx Distributor (LD) ground nut be used for multiple ground connections like a bus bar, and then earth ground that connection to my AC service panel. I have a Multiplus II, MPPT Charge controller both chasis grounded on the LD grounding lug. I want to add my battery ground to the LD ground nut and then earth ground the LD to the grounding bus bar in my AC service panel. I'm following local codes but want to be sure this is a permissible connection. Also, I'm using the SmartShunt, would I ground the neg bat terminal or one of the terminals on the shunt instead. Thank you, any insight or opinions (regardless of code) is appreciated.

duswami asked

0 Answers

Lynx Distributor OK to use last negative stud for chassis ground?

I'd like to run chassis ground to the last negative stud on the lynx distributor - by last negative stud I mean the last stud on the neg busbar, the one that would typically be used to connect a lynx distributors to another lynx distributor. Is there any issues with that? I'm running a multiplus equipment ground to the dedicated ground connection on the lynx distributor. Thanks!

jeremyh asked
jeremyh answered ·

2 Answers

Continuous and Peak Current Limits of Lynx Distributor?


I'm planning out a system for taking a house off-grid, using 3 MP2 10k's in 3-phase (I want to be able to power a Level 2 EV fast charger at full capacity (3-phase, 22kW total)

Can I safely use Lynx Distributors as my busbars, with their listed current rating of 1000 Amps? It doesn't specify whether that's continuous or peak.

By my math, fully-loaded, the multipluses will each draw 8000 Watts continuous, worst case system voltage of about 40 Volts (low SoC and 5 volt voltage drop) gives around 600 Amps continuous, which should be fine for the Distributors.

But, the MP2 can peak at 18,000 Watts for <0.5 seconds (https://community.victronenergy.com/questions/4454/peak-power-of-victron-inverters.html). During that time, assuming a worst-case scenario (all 3 peaking at once, low SoC, 5 volt drop), current would be about 1,350 Amps.

Can the Distributors handle that? I wasn't able to find a separate peak and continuous rating for them, only 1000A.

My understanding is that there's no way to limit the current the MP2s draw from the battery when AC in is not connected, other than by turning loads off. Is that correct?

I don't ever expect to actually hit that peak load. Is fusing the busbar's connections to the batteries/mppt controller (which I'm obviously going to do either way) at some point below 1000A total sufficient to make sure the system is safe, if I would ever exceed the 1000A draw from the MP2s?



josephtate13 asked

0 Answers

Lynx Bus Balance System Question?

So when reading the Wiring Unlimited doc, it shows connecting up multiple batteries in parallel in a configuration where your pos/neg taps come from opposite ends of the busbar like on page 19 and 26:



Now, how does this vibe with the typical Lynx install where each battery is connected to the bus and then the ends of the bus are connected to the next Lynx Component using the nearest corners instead of the opposite corners. In the standard system below it would look to me that potentially all the power is going to preferentially come from the first then 2nd, 3rd, 4th battery instead of spreading it equally. Seems like a bit of a departure from previous recommendations.


I'm definitely giving Victron the benefit of the doubt on this. Maybe the balancing is not a big deal and they will self correct over time, or maybe the bus bars are high enough quality that it doesn't really add any extra resistance for the ones on the end. It may be why they stress to use exactly the same links for each battery when connecting to the bus bar.

Anyone want to shine a bit of light on this topic?

PS. I love the Lynx system and pretty much all the Victron products. Just trying to wrap my head around something that has been nagging me for a while.

hoeken asked
hoeken commented ·

2 Answers

Victron USB to VE Direct using Hub issues connected to Victron 48/3000-GX

I have 3 Mppt controllers with a Victron ET 112 Energy meter via a USB ac powered hub

using VE Direct to USB hub converters

as the GX has only one usb Port and one VE Direct port

the 1 Mppt goes direct to the VE Direct port

the Et112 and 2 x MPPT go via the USB powered hub into the USB port

every time the power fails ac in and comes on again i loose the 1 or 2 MPPT saying no device

if we reboot the GX device it shows up again

we dont want the expense of installing a full on Cerbo GX device

anybody have simalr issues it is very annoying having to reset all the time


soltron365 asked
soltron365 answered ·

2 Answers

Busbar with thermal circuit breakers
Numerous Victron schematics show thermal circuit breakers connected with a busbar. How is this implemented? The thermal breakers used in marine systems have a raised tab that seems to prevent installation of a busbar.

From Victron schematic:


Closeup of breaker:


Rob asked
drlbradley answered ·

4 Answers

distributed batteries

background: i dont have all my space in one place, for the batteries.

am i allowed to do something like this in the pictured wiring diagram? you'll notice i can fit my first 2 batteries nearby the distribution bar (1000a) (0.5m)

but the next pair of batteries will need to be further away (3m). and the next pair of batteries (potentially) the same distance away again (3m).

batteries : i am intending on powertech us2000c - 48v.


mattw asked
mattw answered ·

2 Answers


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