Victron Solar controller's

[BernieQ2]

Can anybody give me the reason Victron says to have the controller close to the battery/s
I have a 100/30 Victron controller but would rather place it in a more useable area...for me.
approx.2.5 to 3mt from battery. give or take.
I'm going to use 6b&s twin.
Bernie.

[T1 Terry]

Are you going to use a Victron 712 BMV? If so, you can network the BMV to solar controller and it will read the BMV voltage direct from the battery. If you don't use a BMV, then the controller has to be as close as possible to avoid the voltage rise seen at the solar controller caused when current passes through a cable.
To get less than 0.1v rise over 3 mtrs you would need close to heavy battery cable, 35mm sq, 6 B&S is only 13.5mm sq and the voltage drop would be approx. 0.3v. This means, if the full charged voltage is set at 14v, the controller will stop charging at 13.7v, then turn on, then off, then on .... till it fails.

T1 Terry

[BernieQ2]

Thanks Terry... it's blue tooth I can/will see state of charge on phone..
I wasn't going to use the 712BMV.
Bernie.

[T1 Terry]

Thanks Terry... it's blue tooth I can/will see state of charge on phone..
I wasn't going to use the 712BMV.
Bernie.

Then you will need to mount it very close to the battery ..... the size cable you would need to mount it 3 mtrs away yet keep the output voltage roughly the same at both ends of the cable is thicker than what will fit in the solar controller terminals.
Victron make their equipment to work together to solve a lot of the problems associated with MPPT controllers in the past. The only other method was the manufacturer would add voltage sensing cables to connected to the battery separate from the charging battery cables .... but most installers didn't seem to understand the need for them so they never connected them up correctly ..... so they did work as well as the should have.

No idea how you will see the state of charge on the phone if you don't have a BMV that can be tuned to suit lithium batteries, the Victron MPPT controller will only send panel voltage and current along with battery sensed voltage and charging current, it can't do state of charge, that requires a BMV

T1 Terry

T1 Terry

[BernieQ2]

So I will have to mount it close to the battery, it's will be out of sight

Next question, I want to mount 3 household solar panels... What are the pitfalls.
Bernie.

[Newcastle George]

Move the battery Bernie.

George

[supersparky]

Make sure they are adequately secured to the roof of the Winny. On our recent trip back from Vic, we saw a pair of panels and their mounts and cable laying on the side of the highway. Looked like the mounting blocks had detached from the roof of whatever they had blown off from.

[jon_d]

Next question, I want to mount 3 household solar panels... What are the pitfalls.

You can't wire them in series because it exceeds the Victron's 100v input rating.
Which means they need to be in parallel, which then means, blocking diodes are needed and heavy cable at the point where they join.

[T1 Terry]

So I will have to mount it close to the battery, it's will be out of sight

Next question, I want to mount 3 household solar panels... What are the pitfalls.
Bernie.

We are talking about a Victron smart MPPT controller, there is nothing to see so why would it being out of sight be an issue?

Household solar panels, you need the VOC to be all the same, add the 3 voltages together and that is the first number you require on the controller, so you will need that VOC number to be less than 33v .... and that isn't likely with roof mounted panels ..... the next bit is the total solar output, say they are 250w panels and you want to charge a 12v battery that requires a fully charged volyage of 14v roughly.

250w x 3 panels = 750w divided by 14v = 53 amps .... sounds like you have the wrong Victron controller for the panels you want to use .....
The normal method is to start with the panels and calculate which controller you need, not the other way around ..... let me guess, you got the Victron 100/30 MPPT controller cheap Most probably because the previous owner of the unit realised it wasn't big enough to do the job they required
We generally only use 30 amp units as an add on to make up the capacity required, like a 100/50 and a 100/30 gives a total capacity of 80 amps. Many of our systems charge at well over 100 amps so multiple units need to be paralleled to get the capacity, then they are all networked to the BMV so they each get their battery voltage sensing from the single source so don't need to turn off to measure the battery voltage with no charging occurring .... this was the old outdated method of MPPT solar control and made them less efficient and harvest less than the PWM solar control method.
These smart control network systems haven't been around for all that long, the earlier stuff isn't compatible with the newer stuff either ..... such is the way of progress, new technology is rarely backwards compatible these days

T1 Terry

[BernieQ2]

At the moment I only have one panel... guessing 80w...it is charging the battery through the PSW solar controller.
I might change to two solar panels and run two systems leaving the old system where it is with a 100a AGM battery.running some of the house.
And no, it's a brand new victron controller
I bought and still to mount.
Bernie.