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markbng avatar image
markbng asked

Campervan 48V 16S system. Charging with Dynamo or Multiplus II

Hello,

A friend wants to use a 16S/320A (48V) battery in his campervan to power the 230VAC devices. He wants to use a MultiPlus II and Orion smart for his campervan. I noticed that the Orion smart is not available for 48V devices. Is the smart not available for 48V? It’s easier to use a 48V battery, because the current will be lower and so the wires will have a smaller diameter. Power loss over the cable is P=I²*R.

So do I need a 24V battery? The battery will be powered by this Orion smart from the dynamo of the campervan (24-28V). Charging power/current is limited! I assume that I have to use the power from the key contact so I twill only be powered when the campervan generates power. Relay with the Orion contact? The other option to charge the battery is by applying AC in to the MultiPlus II. The critical power output will be used to power the AC in the campervan. Is it right that this will also generate power when there is no external AC power is provided?

I suggest 3 setups to him:

  1. Orion smart. 24V seems to be the maximum voltage. So an 8S configuration and a Multiplus II 24/3000. I don’t like this configuration. The current is double and the power loss over the connected cables is 4 times as much. So thicker cables are needed. The Multiplus II is a non GX version. It will be initialized with a VE.Direct to USB and a computer. The SoC can be determined by the orion smart app?
  2. Dali 16S BMS and powerful high performance DC-DC converter 24-58,4V(CC/CV output). I saw you can interface the Dali BMS in 250kbps mode with Victron products. Hopefully the Dali BMS can limit the charging current. Where do I find this DC-DC converter? I don’t prefer to use this option. I want to use a smart, since that is needed for a battery. But there is no smart Orion 24/48? I also use a non GX MultiPlus II 48/3000 here. It will also be initialized with a VE.Direct to USB and a computer. Without a GX it’s impossible to determine the SoC?
  3. Preferred but most expensive. Orion 24/48(not smart, but smart is needed to charge a 48V battery perhaps), multiplus II 48/3000 GX and GX touch. Can data also be seen on the phone(Bluetooth perhaps)? Is there a VE.Direct/Victron communication port on the Orion to communicate with the Multiplus II? How does the Multiplus see the charge status of the battery when it is charged with the dynamo? How can I limit the charging current (important!). Shunt resistor? Can I set a certain (power) limit in the Orion?

Any suggestions are welcome. I really prefer a 48V battery (2 and 3) to reduce cable diameter and to avoid power loss. Any recommendations for a 48V setup are very welcome.

Best regards,

Mark


Ps. any help is welcome. Thank you.

Multiplus-IIOrion DC-DC Converters not smartcampervanorion smart16s
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markbng avatar image markbng commented ·

powerloss is not 4 times, but increased quadratically. my mistake :(


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2 Answers
Justin Cook avatar image
Justin Cook answered ·

For obvious reasons, self-built batteries are not Victron-supported and as such, you're a bit on your own there - when doing such a build yourself, you'll need to spend a lot of time studying the manuals (and physics) of all the associated equipment to sort out how it may -or may not- all work together, or alternatively consult a reputable and experienced systems installer to assist.

That said:

1. Yes, you must have a BMS on the system

2. Orion-Tr Smart are not available in 48v, no

3. The Orion-Tr Smart cannot determine battery SOC, no, you'd need a battery monitor on the system

4. The MultiPlus will not be initialized with a VE.Direct to USB Interface, it isn't VE.Direct. You will need an MK3-USB Interface (VE.Bus) to program the MultiPlus

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jetlag avatar image
jetlag answered ·

I would not recommend a 48V system in a camper van in this situation. What is the board-voltage? 24V, right? Then stay with 24V.

More important is to know what kind of loads you are going to pull, - not as a short peak, but continously? Is 2,4kW really needed for loger then e.g. 30 min or so? And even you need this power for a longer time, this is still a little bit under 100A with a 8S "24V" system. And the battery capacity will anyway limit the time with such high loads.

Such currents in a 24V system are still good manageable with good cabeling and connections.

Anyway, - despite the voltage, you need a smartshunt or other battery monitor to monitor the battery.

If you chose a Multiplus2-GX, then you don't need the MK3-USB device.

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