Hi, I have four pylontech US5000C batteries wired to my lynx distributor using a diagonal pattern as shown in wiring unlimited. But, I thought it might be a good idea to double up the cables to limit the current. They are the standard 25mm pylontech cables. Should I use a 'double diagonal' pattern as shown in the image?
Thanks, Steve
@stegzzz The pylontech US5000C manual gives this option in the section "5.10 Multi-group mode".
Keep your leads between the batteries and bus equal lengths to ensure current balance.
At best this is not neccesary assuming you are using the correct wire sizing. Though I doubt it would be a problem under most circumstances I would suggest you wire as recommended in the manual and the wiring unlimited book, which is a great resource for these types of questions.
https://www.victronenergy.com/upload/documents/The_Wiring_Unlimited_book/43562-Wiring_Unlimited-pdf-en.pdf
I think if there were any good reasons to do this then it would be documented.
The reason I was looking at this is there appear to be some questions about the current limits on the pylontech supplied cables. I happen to have some spare pylontech cables so I was trying to find a way to sidestep the possible problem using the parts I have.
https://community.victronenergy.com/questions/41642/pylontech-battery-cable-spec.html
RE: How to connect 4 batteries in parallel?
There are four schematics in W.U.
You picked the least desirable schematic.
Schematics #1, #2 & #3 are superior.
@stegzzz Hi in the UK we Have a similar arrangement that increases the amp carrying current capability and splits the load to equal parts same distance top and bottom we use this in our houses AC wiring called a ring circuit. This way was used in the war when copper was expensive and 4 to 6mm would have been too expensive or in really short supply but allowed you to carry the same amount of amps for the highest load parts in the house namely kitchen but some house were run of of one ring circuit in the day. Now it’s not really used and instead radials are used more so as it’s simplistic and harder to unknowingly break spur into. Hope this helps
it’s a good wiring arrangement more expensive than the bus bar but equal draw from top or bottom this way two cables neg pos at the top and neg pos at the bottom retuning to original start point! With the addition wires that you installed it’s a ring circuit
I don't want to be there when you switch this on. A 24V Phoenix won't like this. (Yes, I know you're using a Lynx)
Seriously, if you have the cables, create two pairs of the batteries, wire each with the diagonal pattern to the Lynx.
FWIW, I've got two US5000C batteries and I'm using a pair of Pylontech cables for EACH battery. Why? Because the US5000C can deliver 100A continuous which is what the battery cables can sustain, with a peak of 120A for short duration.
Also, the Pylontech battery cables are 4AWG which is about 21mm2 and the only reason they can handle 100-120A is because they have high temperature (105C) insulation. But do you really want your battery cables to run at 105C? Does that sound efficient or safe?
So I run each battery module into my Lynx Power In (modified to accept fuses like a Distributor) with 125A mega fuses for each module. That protects the cables from overload, improves efficiency and reduces heat. Yes it costs a bit more for extra cables but I believe that small extra cost will be offset by improved efficiency over a relatively short time period.
