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tyrone-thomas avatar image
tyrone-thomas asked

Busbars or Lynx Distribution with Mulitple DC Consumers and Sources

I am planning a system with

2x Victron Energy Quattro 24/5000/120-100/100 Inverter with Charger - 120V

3x 100/50 Charge Controller w/ Bluetooth

3(to start and growing)x 24V 100Ah LiFePO4 Batteries

1x DC-DC 23-12 inverter

According to "Wiring Unlimited - Rev 06 page39

(https://www.victronenergy.com/upload/documents/Wiring-Unlimited-EN.pdf)
" If the system has only one battery bank you should connect the battery bank in the middle of the busbars. But in case of several parallel battery banks or smart batteries, they should also be distributed evenly along the busbars. "

I am considering the Lynx distribution system. In the Lynx Distributor System Design

https://www.victronenergy.com/media/pg/Lynx_Distributor/en/system-design.html#UUID-b83b9114-46c7-485b-541b-dfc258a29489

Shows an ideal configuration would be lynx distributors on on either side of a lynx smart BMS in between. This would seem to be in conflict with the diagram recommended in the wiring guide.


Should I use busbars instead of the Lynx Distribution system?

MPPT ControllersBMSmultiple inverterswiring diagrambusbar
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3 Answers
Matthias Lange - DE avatar image
Matthias Lange - DE answered ·

In my opinion it looks cleaner with the Lynx system, but you also can use busbars, it's up to you.

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seb71 avatar image
seb71 answered ·

For that kind of power, make a 48V system (not 24V).

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tyrone-thomas avatar image tyrone-thomas commented ·

let me preface with the fact i am a newbie. But i thought given my panels are 48V and 10Amp VOC, I can pair 2 and charge a 24V batt more reliably in low sun and at closer to max charge current. I also worry about the price differential on 48V equipment vs 24V. as it is i picked 3 smaller contrllers in part because of fault tolerance but mostly because the price of 3 was less than the price of a corespondingly sized single unit.

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seb71 avatar image seb71 tyrone-thomas commented ·

I would say to put any purchase on hold and read more about all these components.


For instance, regarding the chargers, you can get double the power from a certain solar charger if it is used in a 48V system (48V nominal battery voltage), compared with the case of using the same charger in a 24V system.


The 100/50 from that charger name means it can take a PV array with maximum 100V.

For larger systems, look at solar charge controllers with at least 150V PV voltage (maximum allowed). You also need to leave a safe margin to account for low temperatures, when the PV voltage is higher.


The "50" from the charger name means it can charge the battery with maximum 50 A (if it has enough power from the PV array to do that).

In a 48V system this gives you a maximum of about 48Vx50A= 2400W.

In a 24V system this same charger gives you a maximum of about 24Vx50A = 1200W.


So in the first case you can put a 2400W PV array on a single charger and in the second case you need two chargers, each with a 1200W PV array, to get the same 2400W output power.

(This is a simplified explanation)


Higher battery voltage also means you can use thinner wires (because you deal with lower currents). These thinner wires are much cheaper and also easier to route (easier to manage/ to place in position).

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tyrone-thomas avatar image
tyrone-thomas answered ·

Thanks for your answers @Seb71 and @Matthias Lange - DE. Are you both saying the Victron guidance " But in case of several parallel battery banks or smart batteries, they should also be distributed evenly along the busbars" is incorrect and doesnt matter? Cleaner install is a consideration but power loss, inefficiencies, dc oscillation are my chief concerns.

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Matthias Lange - DE avatar image Matthias Lange - DE ♦ commented ·
In my opinion your planned system is not so big that you will have problems with power loss or inefficiency

The Lynx system has very big busbars and is rated for 1000A. Even at full peak power of both Quattro you will "only" have around 800A.

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shaneyake avatar image shaneyake commented ·

I agree with Matthias.


Also if you went 48V which would also be my recommendation for a system this size your current would be halved.

From what I can tell this looks like an RV system, so it will really be up to how you are able to layout your panels. Can you put 2 or more panels in series you can easily have a 48v system.


Also do you have a generator? If not a Multiplus-II might be a cheaper option.

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