How should I connect a victron 12 2000 80 inverter, an victron 12 volt 30 amp mppt, an vivtron 12 18 dc to dc and a victron 702 with shunt.
I also have two 300 amp buss bars
Help
Jeff
Hi Jeff, welcome aboard the community!
That’s a nice collection of equipment. 
Can you tell us a bit more about your intentions? e.g. what are you hoping to achieve, is this for a home, RV, boat, hobby project ? Did you talk to the dealer that sold you all these goodies about hiring a professional installer to lend a hand?
It would also be good to know what you have for solar panels, batteries, and what you want the DC to DC for, and what kind of loads you are going to attach (AC and DC).
Then I’m sure some folks here could help point you in the right direction.
Cheers!
This is for my class C RV, I did ask the dealer for advice.
My solar panel is a fold up 200 watt.
I am just trying to ensure I connect everything correctly
Help
I am only going to run the propane/shore power frig and lighting.
It’s always best to plan these projects - the devil is in the details.
Loads:
So start with an inventory of all the loads - the items you intend to run, and the rated maximum power consumption details.
Here’s a simple example (rough calculations, no extra margins, just to get you started):
- Fridge 120V 400W - it will be on the name plate with the model number, serial number
- Computer 120V 65W - usually on the power supply
- Lights 12V 40W - that’s not a lot of light, I’ve assumed 12V LEDs
120V total: 400+65 = 465
12V total = 40
Inverter efficiency: 85% (from the tech specs on the data sheet… you’ll have to look it up)
465 / 0.85 = 547W
547 + 40W = 587W minimum system capacity to run that stuff.
Since its running off a nominal 12V battery setup, 587/ 12 = 49Amps.
Power Sources:
List where you can get power:
-
“House” Batteries - the ones that will be solar charged and run the equipment in the RV when parked somewhere, engine off.
-
“Starter” Battery - this is for the engine, and not used for the “house” equipment. It’s critical and you don’t want to run it down.
-
Alternator - it charges the starter battery, and might have some capacity to run accessories.
-
“Shore Power” - if you are parked somewhere like an RV park where they have an outlet you can plug into.
-
Solar - when the sun shines and the panels are perfectly pointed at the sun, and all is good, this can provide power to House batteries and Loads.
-
House Batteries
Let’s pretend you have one 12V 100Ah LiFePO4 battery.
The typical continuous discharge rate on a LFP battery is 0.5C, so 0.5 x 100 = 50A
The example above was 49A, so that is the most stuff you could run off this battery, if everything was ideal, no losses, no extra margin.
So you’ll need more battery power.
How long will the battery last? Keeping it simple 100Ah x 80% Depth of Discharge (from the LFP battery data sheet) / 49A = 1.6 hours, or about an hour and 35min. Not very long!
- Starter Battery and Alternator
The number 1 job is to keep you moving.
The alternator tops up the starter battery after engine start and this can take a while. Your alternator has to provide power to headlights, signals, the RV electronic systems; if any capacity is left over, maybe 50% could be used to run to the DC to DC converter to charge the House batteries.
The starter battery might be 12V AGM (so a 14.4V system) or 12V FLA (13.8V)
The alternator may have a rating eg 110Amps.
You’ll need to find this out.
- Shore Power
There’s probably an existing shore power connection and it probably goes to an electrical panel with the fridge etc on it.
Do you want that shore power to charge up the house batteries?
- Solar power
Which model do you have? eg Victron SmartSolar 100 30 MPPT ?
Equipment inventory:
Make a specific list of what you’ve bought - eg the Invoice/Bill of Sale will help. There are so many variations in the Victron world, it helps to know the exact models.
You’re going to need fuses, breakers, disconnects, and heavy gauge wiring
Is your RV based on North American (Chevy) or European (eg Sprinter)? Some RVs have energy management systems - does yours?
Basic Hookup:
LFP House batteries
- negative to Victron 702 shunt battery side
- positive to Class T fuse rated for the kind of load you will be running.
Bus bars
- Negative bus bar to load side of the 702 shunt
- Positive bus bar to the class T fuse
Solar Panels to MC4 combiner box → disconnect, fuse and lightning surge protection → MPPT PV input.
MPPT battery [+] to a fuse and maybe a victron disconnect switch - to the [+] bus bar
MPPT battery [-] to the [-] bus bar
There’s a lot more that has to happen, so you’ll need to do your homework.
Good luck! and consider hiring a pro.
Is this for dc power/loads?
Can your battery discharge at least 166amps?
Is this the 100/30 or a different model? The 100 refers to the solar panel voltage open circuit.
The dc to dc is to help keep the battery charged because I use the inverter to keep the frig running while driving, once we are parked we run the fridge off propane.
The mppt is a victron 100/30
flowchart LR
Solar[Solar Panels] --> MPPT[MPPT 100/30]
POS[Positive Bus Bar]
NEG[Negative Bus Bar LOADS]
NEGBAT[Negative Bus Bar - Batteries]
BAT1[LiFePO₄ #1]
BAT2[LiFePO₄ #2]
SHUNT[BMV-702 Shunt]
INV[12/2000 Inverter]
ORION[Orion 12/12-18]
START[Starter Battery]
MPPT -->|+ 45A fuse| POS
MPPT -->|-| NEG
BAT1 <-->|+ 100A| POS
BAT2 <-->|+ 100A| POS
BAT1 -->|-| NEGBAT
BAT2 -->|-| NEGBAT
NEGBAT <--> SHUNT
SHUNT <--> NEG
ORION -->|+ Output 25A fuse| POS
ORION -->|- Output| NEG
START -->|+ Input 25A fuse| ORION
START -->|- Input| ORION
POS -->|+ 200A fuse| INV
NEG -->|-| INV
That would be the basic power flow then. I just guessed at how many batteries you had for the inverter. It could be simpler if is just a single battery.
I have two victron super pack ng 200 ahr batteries in parallel
Would that change your diagram.? Only having one pos and one neg
I was going to connect the batteries with two 2/0 cables in parallel, one going from positive to positive and another 2/0 cable going from negative to negative.
So I would have one positive cable going to the positive bus bar and one negative cable coming from the other battery going to the negative bus bar .
Is this correct and thank you for your responses
Jeff
Hi Jeff, I think you need a fuse on each battery +positive before connecting to the positive bus bar. @lxonline may have a specific suggestion - he’s amazing!
I intend to use an mega 200 amp fuse and the reason I chose a 200 amp was because I only use the inverter to keep the frig running and maybe a light. When we are parked we run the frig off propane.
I like the connection diagram from @lxonline, and intend to go that way as to the connections but I am still unclear as to how to connect the victron shunt.
I am thinking of connecting batt + to the positive bus bar + and the batt - to the negative - to the neg - bus bar.
Connecting the neg - bus bar to the load side of the shunt.
Connecting the mppt and the dc to dc to the bus bars.
I am stuck on how to connect the inverter ?
Help
Jeff
Forgot on thing, I have blue sea breakers on the POs + side coming into and out of the mppt and dc to dc
Between the battery negatives and the negatives of the rest of the system.
Sometimes this requires 2 negative bus bars. Somtimes the lugs are stacked. I am not a fan of the stacking. But must needs sometimes. Just make sure if you do that the cable is properly supported not just hanging off the shunt bolt.
Yes. Do that.
Thank you for your help but I have just one more question and that is should I connect the multiplus inverter positive to the positive bus bar with a 200 amp mega fuse in line and the inverter negative to the negative bus bar or if not how would you connect the multiplus positive and negative cables.
Again you guys are great I can’t get much help from the dealer and I want to get this right.
Also how do you feel about having 1/4 inch cement board behind the dc to dc and the inverter
Thank you
Jeff
Fits the not flammable surface requirements.
Vibration may be an issue with screws. So mahbe bolt through with locktight. And don’t mount where the vehicle flexes.
Your inverter wiring set up is ok to the bus bar.
The onky thing you have to make sure of is keep right is the shunt must be the only thing connected to battery negatives. It is the most common mistake i see in DIY installs.
Looks good.
Are you confident with cable sizing?