Switching out Magnum to Victron

[Tony Ramirez]

I'm considering changeing out my Magnum 2012 to a Victron Multi Plus,. I'm sure I'll have a lot more questions, but this is the first one.

The Victron has 2 lugs each (+&-)for the 12V input. Right now, I have one each 4/0 cables going from my Buss bar in the batt compartment on the passenger side, to the Magnum on the drivers side. I haven't measured the exact length of the existing cables but I'm guessing 8' wide rig, plus bends & curves, probably around 9-10". My batt cables going into the Buss bars are the exact same length.

Here's the question: Can i just add another 4/0 + & - cable 10' long each and not have any issues, since they would be coming off a Buss Bar, or would I run into problems? Or should I pull the existing calbes to get the exact lenth mesurement? I've read about cables needing to be the exact length for battery balancing & stuff.

Thanks

[jberger]

You only need to worry about wire length inside the battery pack, the run from the pack to the inverter doesn't really matter.
When stringing together multiple batteries into a single pack, keeping the inter-pack wiring equal helps make sure that one battery doesn't charge or discharge faster than the others.

Is there a reason you want to add another 4/0 run between the batteries and inverter?
That isn't really going to buy you much in terms of current, but is going to double the number of fuses you need to keep the line protected.

[twinboat]

Since your not traveling in outer space, a few inchs of difference in cable lenght, especially 4/0, won't make a difference.

Why do you think you need to double up the cables. The second inputs may be to parallel another inverter.

[SavnTheWales]

Going from the Magnum 2012 (2000watt) to a Victron Multiplus (3000watt) does mean you need to check a few things. You will be adding a potential of 80+ additional amp draw.

You said you have 4/0 cables so you should be fine with the amp draw on those. However, what are your bussbars rated for? You will want a minimum of 250 amp bars. You may also have to replace existing fuses to larger one to accommodate the higher amp draw.

Also use this opportunity to check all cable ends and resistance. You might fine that some ends have corrosion in the crimped connectors. This happened to me and I had to cut off bad end and replace.

[Tony Ramirez]

Thanks Berger & twinboat, that answers that. I assumed since it had 2 12v posts, i would need 2 cables. Didn't think about paralleling. I'll stick with my 1 4/0.

[Tony Ramirez]

Thanks savnthewales, my buss bars are 600A, so I should be okay. I had thought of that. I will probably change out ny circuit breaker for the inverter cable to a higher rated one.

I'll also check my cable ends, thanks!

[skitime]

I have done the same thing. I had the Dimensions 2000 watt inverter on the driver's side in front of rear wheels and the battery compartment was behind the passenger rear wheels. I mounted the Victron 3000 watt inverter flat under the bed above the battery compartment. I eliminated the old battery cables to the old inverter. Those cables were 2about 20' long. I then used 3/0 battery cables of only about 6' long.

[TechWriter]

Originally Posted by Tony Ramirez

The Victron has 2 lugs each (+&-)for the 12V input . . .

Here's the question: Can i just add another 4/0 + & - cable 10' long each and not have any issues, since they would be coming off a Buss Bar, or would I run into problems? Or should I pull the existing calbes to get the exact lenth mesurement? I've read about cables needing to be the exact length for battery balancing & stuff.

From the Multiplus II Manual . . .

Those dual lugs follow Victron's recommendations: For the Victron 12/3000/120, Victron recommends two, 1/0 cables for up to 5m (16') runs and two, 2/0 cables for 5 to 10m (16' to 33') runs. However, I used a single 4/0 cable for my under 10' cable run. Nothings melted so far.

Also, Victron recommends a 400A fuse should be used. I'd also recommend a 1000A Victron Lynx Buss Bar.

[Tony Ramirez]

Thanks Techwriter, I'll probably stick with the one 4/0. I did see the Victron recommends two 1/0 though.