goon326 avatar image
goon326 asked

Setting up a new system with: BMV 712, SmartSolar MPPT 75/15, Phoenix 12/1200

Dear Community,

For my campervan I am creating a system of the following products and I have some questions about them, hopefully somebody can help me.

I am going to use the following setup in my t4 California Westfalia from 1991:

  • 130wp solar panel (and maybe a second one)
  • SmartSolar MPPT 75/15
  • BMV 712
  • Phoenix 12/1200
  • 200 ah Lithium battery (not from victron)

I want to use all Victron products in the victron app if possible.

The first question is, can I connect the Phoenix 12/1200 via VE.Direct to the MPPT or the BMV so that I can use it in the app or do I need the bluetooth dongle? I found the dongle rather expensive for what it can do.

Second question, I maybe want to use an battery temperature sensor that works together with my MPPT, is the only possibility the Smart Battery Sense? Or can I also use the battery sensor from the bluetooth dongle? Or the Battery sensor that can be bought for the BMV? And what is the difference between them?

Third question, do the lithium batteries of victron have a power shut off on a certain temperature that is to low or to high? I read some batteries from other brands do shut of at -7 or something. And what is the benefit from an external battery management system that Victron recommends and sell on top of the internal BMS?

Fourth question, would it be recommended to switch my current lithium charger for one from victron? Or is that useless?

Kind regards,


BMV Battery MonitorMPPT SmartSolarPhoenix InverterVE.Bus Smart Dongle
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2 Answers
Justin Cook avatar image
Justin Cook answered ·

1. No, the Phoenix cannot connect to the MPPT over VE.Direct; you'll need the VE.Direct BT Dongle to add BT functionality to it.

2. The Smart BatterySense can be used, or you can connect the wired BMV 702/712 temperature sensor to the BMV, and use the BMV for your VE.Smart Networking to send real battery voltage and temperature data to the MPPT.

3. A Victron BMS cannot be used with non-Victron batteries, so you don't need to worry about that.

4. Not knowing what LFP charger you currently have, I couldn't offer conjecture about whether you should swap it out or not. If it's working for you, I'd say no reason to swap it out at this time, but that's a judgement call on your side.

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goon326 avatar image goon326 commented ·

How useful is it to add the dongle for the phoenix? And do you think that the MTTP is big enough if I add another 130wp panel?

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Justin Cook avatar image Justin Cook ♦ goon326 commented ·
The Phoenix works just fine as a standalone, but if you want to see what it's doing, update FW, and change settings via BT then the dongle is worthwhile.

Proper MPPT sizing can vary wildly depending on a number of factors; you can use Victron's MPPT Calculator to narrow it down, but by the very basic math, 260w/13.5v=19A under ideal conditions that you'd never actually see, so the 75/15 is probably fine so long as you stay well under the 75vDC input limit.

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goon326 avatar image
goon326 answered ·

Is adding an Isolated Orion-TR Smart DC-DC battery charger useful? I have an 1992 westfalia system with a relai between the start battery and the household battery and an regular alternator that gives with lights and engine on between the 13.7-14.0 volt. And which size should I take?

Start battery: 80ah lead battery

Household battery: 200ah lithium with BMS

Alternator: 14v 90ah

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