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jsheehan avatar image

Can you connect the Cables in the Pylontech Kit to a Multiplus II 48/5000?

Hi,

I was just wondering if you were able to use the Cables in Pylontech's Cable Kit and connect it straight to a Multiplus II 48/5000. The Multiplus II recommends the cable to be 70mm^2, while the cables in Pylontech Kit are 25mm^2. Also this might be a dumb question can you cut the Pylontech cables and put them through a dc fuse disconnector and cut it again and place in a Lynx Distributer and then eventually to the inverter charger?
I created a quick diagram of what I am planning to install.

screen-shot-2021-10-13-at-104232-pm.png

Pylontechcable
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1 Answer
markus avatar image
markus answered ·

Hi,

50mm2 DC connection per pole should be good for a 48V MP2 5k, if you have short cable runs (<2m per pole).

You could use 2 Pylontech cable sets to have 2x25mm2 per pole. Connect them to the Lynx Distributor and from there, go with 50mm2 per pole to the Multi. It is OK, to have a fuse before the Lynx. Act, according to your local laws.

You don't need a BMV, you will get SOC from the battery via CAN.Bus. For that, Use Victron Can Cable (Type B or Type A depending on exact Pylontech model) and connect it to your CerboGX. Don't forget the terminator on the Cerbos 2nd CAN.Bus port (BMS.CAN). The Battery will tell the system CVL CCL via Can.Bus for proper charging. It is a must to have a (working) CAN connection between the battery and the system.

Give this a read: Victron & Pylontech UP2500, US2000, US3000, US2000C, US3000C, UP5000, Phantom-S, Force-L1 & L2 [Victron Energy]

A 300 Amp fuse for the CerboGX will be oversized. Use the glass tube fuse that comes with the Cerbo DC connection cable.

A 300 Amp fuse for the MPPT is also oversized. 100A will be OK.

A 300 Amp fuse for the Multi is oversized too. 200A will be OK.

If you have additional questions, it will be a good idea to involve a local electrician, with knowledge of the local laws and regulations.

I have yet another reading recommendation: https://www.victronenergy.com/upload/documents/Wiring-Unlimited-EN.pdf

BR


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Thanks for the help! Just wondering if you could please expand about the Terminator on the Cerbos?

The Can.Bus has to be terminated on both ends.

You will have to connect one of these Can.Bus terminators:

946fc968-5b66-400c-9de4-20fe001d5347.jpg

Into this BMS.CAN port:

f9968dc7-72f8-40f8-ba8f-36261d4fe407.jpg

to terminate your Can.bus.

On the battery side, termination is already done inside the battery.

jsheehan avatar image jsheehan markus ♦♦ ·
Thanks Markus, you have been very Helpful. I got one last question. Do you know why Pylontech has a Cable kit that is designed to connect the batteries to an inverter/charger. But they are too small?

There is an explanation from Guy here:

Pylontech battery cable spec - Victron Community (victronenergy.com)

The 4AWG cables supplied as part of the Pylontech cable kit have an insulation temperature rating of 105 degrees.

This allows for the much higher than normal current carrying capacity than you might be used to, or able to find in other cables.


Personally, I would go 2x25mm2 per pole in your case, as suggested above.

jsheehan avatar image jsheehan markus ♦♦ ·
Ok awesome, this might be a dumb question but could you explain what you mean by 2 x 25mm2 per pole. Buy another Pylontech Cable Kit? How do I put 2 cables in the same pole?
Yes, buy a second cable kit.
jsheehan avatar image jsheehan markus ♦♦ ·

This is an official Victron and Pylontech Wiring Diagram and they only have one cable connected per 4 batteries. So confusing.

In this picture I see one inverter connected with 2 cable sets to the battery.

markus avatar image markus ♦♦ markus ♦♦ ·
But I can see your point. If you are still unsure, ask the seller of your battery for his advice.


jsheehan avatar image jsheehan markus ♦♦ ·

Is this what you were suggesting?