Victron power in, shunt and distributor

[Blown284]

Hi Everyone. Building out my system and want to ensure I have everything right. For context, I plan to connect 6, 51.2V batteries up and want to ensure I’m doing it right. Looks like the “Power in” only has 4 slots that can accommodate 4 battery posts. How can I accommodate the other 2 batteries? Also, in order here’s what I’m thinking please correct me if I’m wrong:

Lynx power in (connect all batteries) > Lynx Shunt (connect to power in) > Lynx Distributor (connect inverter and MPPT controller (Victron 450/100)

BTW, i already have the Victron 450/100, Cerbo GX and SmartShunt (will replace this with the Lynx Shunt)

Does each battery post need a separate wire to the Lynx in or can I wire all of the batteries together and then have the two wires coming off them into the Lynx power in?

Sorry for the newbie questions. As you can tell, I’m still learning and willing to take advice / counsel from others a lot more experienced than I.

Thank you!
-Tim

 

[Dinobot248]

To connect multiple batteries to the Lynx power in, buy a sufficiently rated positive and negative bus bar. Connect that bus bar using equal or near equal length battery cables to each of your 6 batteries, then connect that bus bar to the Power In bus bar.

As you added more batteries, get another bus bar. This helps to keep things organized.


Each battery should have their own battery cable to the bus bar to ensure that each battery gets a sufficient opportunity to charge and discharge. Using one battery cable for two or more batteries can be done, but generally not recommended. Your cable would need to be a larger gauge to carry the energy (DC current) from each battery in that daisy chain. Plus, the closer battery bears the brunt of the charging and discharging which makes it work more than the farthest battery, hence it’s better to use a bus bar with equal length wires.


I get confused by the names (eg power in vs distributor). The key is to remember the battery bank is on one side of the shunt and everything else is on the other side of the shunt. The distributor will use fuses for each connection to inverter / SCC and the power-in has no fuse and relies on the fuse in the shunt.

Hope that helps.

 

[Blown284]

To connect multiple batteries to the Lynx power in, buy a sufficiently rated positive and negative bus bar. Connect that bus bar using equal or near equal length battery cables to each of your 6 batteries, then connect that bus bar to the Power In bus bar.

As you added more batteries, get another bus bar. This helps to keep things organized.


Each battery should have their own battery cable to the bus bar to ensure that each battery gets a sufficient opportunity to charge and discharge. Using one battery cable for two or more batteries can be done, but generally not recommended. Your cable would need to be a larger gauge to carry the energy (DC current) from each battery in that daisy chain. Plus, the closer battery bears the brunt of the charging and discharging which makes it work more than the farthest battery, hence it’s better to use a bus bar with equal length wires.


I get confused by the names (eg power in vs distributor). The key is to remember the battery bank is on one side of the shunt and everything else is on the other side of the shunt. The distributor will use fuses for each connection to inverter / SCC and the power-in has no fuse and relies on the fuse in the shunt.

Hope that helps.

Thank you for the reply and helping me!

Copy all on the things you mentioned about cables and such. I am/was planning on using the "Power in" as the bus bar (I thought that's the purpose of them?) so I'm guessing I likely need two of them since there are only 4 posts and that would work since I have 6 batteries. Unless I'm thinking about this wrong?

 

[robbob2112]

First - BUY NOTHING until your plan is complete! This little rule will save you lots of $$ in the long run.


Read this thread - it is pretty enlightning when it comes to batteries, bus bars, and cable placement.

Calculation of parallel string battery currents

Hi, everybody! I'm a retired EE. I didn't want my EE skills to fade away after retirment, so I exercise them when I can. Whenever I see a non-trivial circuit analysis problem on one of various forums I frequent, I challenge myself to solve it. Recently I watched Will's video about current...

diysolarforum.com

You would be better off using multiple of the Lynx Class-T Power In or just a standard bus bar and class T fuses and holders to connect everything together. Then the lynx shunt on the end before connecting to the inverter. For 6 batteries that is 3 of the Lynx class-t power units

Depends on your desire to stay Victron or use some other components.

The lynx distributor uses Mega fuses which do not have sufficient AIC for the number of batteries you are hooking together. You need the AIC of a class T.

Battery connection suggestions - ask questions if you don't understand 'why' on each of these

• Each battery must have its own wire.
• The roundtrip path of the wires must be equal. This means if the total length of your positive + negative wire is 6ft you can make sets up of different combinations. i.e. 2ft and 4ft, then 3ft and 3ft, then 4ft and 2ft, and so on. Or you can just figure the longest roundtrip and cut equal length wires for everything.
• If you do end up with a bunch of extra wire lay the pairs together and tape them along side each other verse coil them. This avoids issues with the magnetic fields and interference from that.
• Each positive wire should have a class T fuse at the bus bar end.
• If the wires are longer than 12" each should have a fuse at the battery post or a built in circuit breaker. The BMS is not a fuse and shouldn't be depended on to act like one. When a BMS blows, it tends to become a short verse an open circuit.

What brand/style/model battery are you planning on?
What type inverter are you planning on and general size of your install?

 

[Brucey]

Thank you for the reply and helping me!

Copy all on the things you mentioned about cables and such. I am/was planning on using the "Power in" as the bus bar (I thought that's the purpose of them?) so I'm guessing I likely need two of them since there are only 4 posts and that would work since I have 6 batteries. Unless I'm thinking about this wrong?

Depending on what specific batteries you are looking at buying or building would decide if you can use two power ins (8 posts for the 6 connections), or three class t power ins.

 

[robbob2112]

P.S. in case you doubt - this thread was caused by a combination of events that can be summarized as

• DIY battery cell shorted out
• cell vented filling the space with hydrogen
• Victron Mega fuse on one pack failed explosively
• House went up

House burned down

So, after 4 to 5 years of working flawless, the 100 kwh lifepo4 battery caught fire at night and burned our house down. Luckily our family just made in out on time. Inspection of the fire expert revealed that a melt fuse melted, and created an arc between the 2 points wich ultimatly started the...

diysolarforum.com

A class T on each battery line _might_ have made a difference or might have made no difference if the ignition source was not the Mega fuse. The certainty is that a class T fuse failure is contained by the fuse itself and in the enclosure.

I doubt that Victron envisioned people hooking up so many high powered batteries in parallel. A fault inside one battery results in all the others dumping current into it. When max current was 50amps or 100amps that was containable with the Mega fuse. But with 200amp batteries that would be 1000amps in your case dumping into one. The result is a 4/0 red hot in under a second and whatever fuses are used will fail dramatically. Note this is if you were looking at 200amp batteries and putting 6 together.

 

[Brucey]

P.S. in case you doubt - this thread was caused by a combination of events that can be summarized as

• DIY battery cell shorted out
• cell vented filling the space with hydrogen
• Victron Mega fuse on one pack failed explosively
• House went up

House burned down

So, after 4 to 5 years of working flawless, the 100 kwh lifepo4 battery caught fire at night and burned our house down. Luckily our family just made in out on time. Inspection of the fire expert revealed that a melt fuse melted, and created an arc between the 2 points wich ultimatly started the...

diysolarforum.com

A class T on each battery line _might_ have made a difference or might have made no difference if the ignition source was not the Mega fuse. The certainty is that a class T fuse failure is contained by the fuse itself and in the enclosure.

You bring up a good point. the blue seas ignition protected class t fuse holders can contain the ignition of gas within the fuse space, to avoid propagating further into the room. Wheras the lynx class t powers ins have significant venting slots on the cover.

 

[robbob2112]

You can use the Lynx distributor for all your SCC connections like you planned.

 

[Dooug]

Depending on what specific batteries you are looking at buying or building would decide if you can use two power ins (8 posts for the 6 connections), or three class t power ins.

I was just thinking about the 3 class T ins. If he has high discharge 51.2 packs this will work. Unfortunately the lynx class t only take 225 amp and higher size class t fuses. Not ideal if some had a couple 51.2 100AH cells that only discharge 100 amps.

 

[robbob2112]

Well, one thing to consider is total possible amps. If he has 6 x 200amp batteries that is 1200 amps and it exceeds then 1000amp bus bars in the victron equipment

 

[Blown284]

Well, one thing to consider is total possible amps. If he has 6 x 200amp batteries that is 1200 amps and it exceeds then 1000amp bus bars in the victron equipment

I currently have 4, 100ah LIPO4 batteries but plan to add two more.

 

[Blown284]

P.S. in case you doubt - this thread was caused by a combination of events that can be summarized as

• DIY battery cell shorted out
• cell vented filling the space with hydrogen
• Victron Mega fuse on one pack failed explosively
• House went up

House burned down

So, after 4 to 5 years of working flawless, the 100 kwh lifepo4 battery caught fire at night and burned our house down. Luckily our family just made in out on time. Inspection of the fire expert revealed that a melt fuse melted, and created an arc between the 2 points wich ultimatly started the...

diysolarforum.com

A class T on each battery line _might_ have made a difference or might have made no difference if the ignition source was not the Mega fuse. The certainty is that a class T fuse failure is contained by the fuse itself and in the enclosure.

I doubt that Victron envisioned people hooking up so many high powered batteries in parallel. A fault inside one battery results in all the others dumping current into it. When max current was 50amps or 100amps that was containable with the Mega fuse. But with 200amp batteries that would be 1000amps in your case dumping into one. The result is a 4/0 red hot in under a second and whatever fuses are used will fail dramatically. Note this is if you were looking at 200amp batteries and putting 6 together.

I'm paying particular attention to safety hence why I'm asking all of these questions to ensure I do this right and it's safe. Thank you!

 

[Brucey]

Well, one thing to consider is total possible amps. If he has 6 x 200amp batteries that is 1200 amps and it exceeds then 1000amp bus bars in the victron equipment

I'm not sure if NEC requirements come into play for DC bus bars. Personally I don't see a problem with over a 1000A of potential battery if your loads won't exceed that (I e your loads could be two 400A connections to big inverters and then say 200A of SCC). But maybe when being inspected/permitted they look at that

 

[SoggyShoes]

Does each battery post need a separate wire to the Lynx in or can I wire all of the batteries together and then have the two wires coming off them into the Lynx power in?

Yes, each battery should connect directly to its own set of terminals in the Power-in or whatever bus bars you use.

I am/was planning on using the "Power in" as the bus bar (I thought that's the purpose of them?) so I'm guessing I likely need two of them

Yes, the power-in is just a bus bar. A really nice bus bar. The "stacking" nature of the positive and negative terminals make for a really clean install and conserves space. You can link them.

The Lynx distributor is basically the same bus bar as the power in but with 4 mega fuse holders.

They make 8mm and 10mm versions. I believe both versions of the power-in are rated to 1000A. They make some sort of smart Lynx BMS that, I think, only works with Victron batteries. The Lynx BMS 8mm is 500A and the 10mm Lynx BMS is 1000A. The 8mm is less expensive so unless your using Victron batteries, go with the 8mm.

Lynx power in (connect all batteries) > Lynx Shunt (connect to power in) > Lynx Distributor (connect inverter and MPPT controller (Victron 450/100)

BTW, i already have the Victron 450/100, Cerbo GX and SmartShunt (will replace this with the Lynx Shunt)

Your order is correct that the Power-in(s) goes the to left of whatever shunt you use and the Lynx Distributor(s) go to the right of the shunt.

My Victron dealer is not a fan of the Lynx shunt and prefers using a Victron smart shunt (which you said you already have) and a switch (https://artek.energy/products/jrd-lynx-shim-plate). Doing this should save you enough money for a second Power-in!

This distribution system is the easy part. You need to figure out what you what to power and how much that will be. Then that should help you figure out what charger/inverter to use, how much solar you need or can do, and so on.

First - BUY NOTHING until your plan is complete! This little rule will save you lots of $$ in the long run.

This is really good advice!

@sunshine_eggo can make sure you are getting correct information about all things Blue (Victron). In fact, I am surprised that there is a thread with Victron in the title and Papa Smurf has gone over 12 hours without coming to your rescue. I thought whenever Victron was mentioned on the forum, a giant blue Batman like signal lit up the sky over a certain part of Arizona.

 

[740GLE]

Yes, each battery should connect directly to its own set of terminals in the Power-in or whatever bus bars you use.


Yes, the power-in is just a bus bar. A really nice bus bar. The "stacking" nature of the positive and negative terminals make for a really clean install and conserves space. You can link them.

The Lynx distributor is basically the same bus bar as the power in but with 4 mega fuse holders.

They make 8mm and 10mm versions. I believe both versions of the power-in are rated to 1000A. They make some sort of smart Lynx BMS that, I think, only works with Victron batteries. The Lynx BMS 8mm is 500A and the 10mm Lynx BMS is 1000A. The 8mm is less expensive so unless your using Victron batteries, go with the 8mm.


Your order is correct that the Power-in(s) goes the to left of whatever shunt you use and the Lynx Distributor(s) go to the right of the shunt.

My Victron dealer is not a fan of the Lynx shunt and prefers using a Victron smart shunt (which you said you already have) and a switch (https://artek.energy/products/jrd-lynx-shim-plate). Doing this should save you enough money for a second Power-in!

This distribution system is the easy part. You need to figure out what you what to power and how much that will be. Then that should help you figure out what charger/inverter to use, how much solar you need or can do, and so on.

This is really good advice!

@sunshine_eggo can make sure you are getting correct information about all things Blue (Victron). In fact, I am surprised that there is a thread with Victron in the title and Papa Smurf has gone over 12 hours without coming to your rescue. I thought whenever Victron was mentioned on the forum, a giant blue Batman like signal lit up the sky over a certain part of Arizona.

A downside of the smart shunt vs Lynx shunt is ease of connecting.

The smart shunt can be made to connect to a Lynx power in but needs a jumper. It can be bolted directly to a Lynx power in, but then needs some drilling and shims to sit flush.

 

[Blown284]

Yes, each battery should connect directly to its own set of terminals in the Power-in or whatever bus bars you use.


Yes, the power-in is just a bus bar. A really nice bus bar. The "stacking" nature of the positive and negative terminals make for a really clean install and conserves space. You can link them.

The Lynx distributor is basically the same bus bar as the power in but with 4 mega fuse holders.

They make 8mm and 10mm versions. I believe both versions of the power-in are rated to 1000A. They make some sort of smart Lynx BMS that, I think, only works with Victron batteries. The Lynx BMS 8mm is 500A and the 10mm Lynx BMS is 1000A. The 8mm is less expensive so unless your using Victron batteries, go with the 8mm.


Your order is correct that the Power-in(s) goes the to left of whatever shunt you use and the Lynx Distributor(s) go to the right of the shunt.

My Victron dealer is not a fan of the Lynx shunt and prefers using a Victron smart shunt (which you said you already have) and a switch (https://artek.energy/products/jrd-lynx-shim-plate). Doing this should save you enough money for a second Power-in!

This distribution system is the easy part. You need to figure out what you what to power and how much that will be. Then that should help you figure out what charger/inverter to use, how much solar you need or can do, and so on.

This is really good advice!

@sunshine_eggo can make sure you are getting correct information about all things Blue (Victron). In fact, I am surprised that there is a thread with Victron in the title and Papa Smurf has gone over 12 hours without coming to your rescue. I thought whenever Victron was mentioned on the forum, a giant blue Batman like signal lit up the sky over a certain part of Arizona.

Now to my next question. What size cables should I be running from my battery terminals to the shunt? I have about a 6 foot run but will buy extra just to ensure I have enough. Thoughts?

Oh and thank you so much for educating me... I'm learning in public here!