Fuses for solar...

[lustyd]

The main battery switch doesn’t usually disconnect chargers, the chargers and batteries are usually on one side and the loads on the other these days.

 

[PaulRainbow]

If you are going to switch the battery side of a solar controller, say by turning off the main battery switch off while leaving the solar panels connected (something I would not recommend), check first that there is not any equipment that can be powered directly from the solar controller. It will be obvious if you have a circuit diagram.

Solar charging should not be wired through the main isolators. The isolators isolate the boat, the charging can keep the batteries charged when the main isolator is off.

Unfortunately, without a battery in the circuit damening the voltage fluctuations, the solar controller will sometimes reach a voltage that may damage equipment.

That's incorrect.

 

[noelex]

That's incorrect.

Try it, Paul, but not on my boat .

If the solar regulator is trying to maintain an absorption voltage of, for example, 14.4V and an appliance such as a fridge cycles off, the voltage will temporarily spike, to 16V and above. The solar controller simply does not react rapidly enough without a battery dampening the voltage. It is not designed to act as a power supply without a connection to a battery.

 

[PaulRainbow]

Try it, Paul, but not on my boat .

If the solar regulator is trying to maintain an absorption voltage of, for example, 14.4V and an appliance such as a fridge cycles off, the voltage will temporarily spike, to 16V and above. The solar controller simply does not react rapidly enough without a battery dampening the voltage. It is not designed to act as a power supply without a connection to a battery.

Once again, you are incorrect.

If there is no battery connection to the controllers battery terminals it cannot and will not attempt to carry out an absorption charge, or any other charge.

What you describe above is absolute nonesense, as is often the case, you're just inventing things.

 

[noelex]

Once again, you are incorrect.

If there is no battery connection to the controllers battery terminals it cannot and will not attempt to carry out an absorption charge, or any other charge.

The algorithm in the charge controller is programmed to maintain the absorption voltage (for example, 14.4V) for the absorption time (for example, two hours). It will do this if connected to any load, whether that load is a battery, equipment drawing power, or, more commonly, a combination of the two.

Some solar controllers will interrogate the battery voltage at solar start-up, but once the charge algorithm is commenced, this charge profile will continue if the battery is subsequently disconnected.

 

[webcraft]

Perhaps i misunderstood what you were thinking...

If you meant a dual circuit breaker that breaks the positive circuits either side of the controller, yes you could do that. But i wouldn't use a circuit breaker, a dual pole switch would be OK, but you'd still need fuses. I would fit a fuse close to the batteries, then you could use a fuse and switch between the panels and controller, or a resettable circuit breaker.

FYI, with Victron MPPT controllers (no doubt some others, but i don't know which for sure) there is no need to disconnect the panels before disconnecting the batteries.

That's good news about Victron MMPTs - no possibility of frying the controller accidentally. I have bought circuit breakers to go between the controller and the battery, and was worried about accidentally bumping it and disconnecting the batteries while the panels were still producing voltage.

Any idea if the Renogy Rover 40 is the same?

— W

 

[PaulRainbow]

The algorithm in the charge controller is programmed to maintain the absorption voltage (for example, 14.4V) for the absorption time (for example, two hours). It will do this if connected to any load, whether that load is a battery, equipment drawing power, or, more commonly, a combination of the two.

The discussion is regarding disconnecting the controller from the battery, doing so removes not only the battery, but all loads, unless they are connected to the load terminals.

Some solar controllers will interrogate the battery voltage at solar start-up, but once the charge algorithm is commenced, this charge profile will continue if the battery is subsequently disconnected.

I'm not talking about "some" controllers, i have specifically stated (more than once) that i'm talking about Victron MPPT controllers.

Please, stop making things up, it's confusing people.

 

[PaulRainbow]

That's good news about Victron MMPTs - no possibility of frying the controller accidentally. I have bought circuit breakers to go between the controller and the battery, and was worried about accidentally bumping it and disconnecting the batteries while the panels were still producing voltage.

No problem here.

Any idea if the Renogy Rover 40 is the same?

— W

Sorry, no idea.

 

[noelex]

The discussion is regarding disconnecting the controller from the battery, doing so removes not only the battery, but all loads, unless they are connected to the load terminals.

This depends on how the boat is wired. As you concede, some boats are wired such that the solar power is wired to the load terminals or downstream of the battery switch. This ensures that there is no possibility of charge or discharge from the battery if the main battery switch is off. It is not unusual.

These different wiring options are why I suggested in post #19 to check the circuit diagram to determine how your boat is wired.

I'm not talking about "some" controllers, i have specifically stated (more than once) that i'm talking about Victron MPPT controllers.

Please, stop making things up, it's confusing people.

There is no confusion: the Victron controllers on their own will continue the algorithm and supplying power to any connected loads once started even if the battery is subsequently disconnected.

A charge controller cannot distinguish between supplying current to equipment or to the battery.

If it did try to disable its output power in the middle of the day to see if a battery was still connected, it would necessitate a pause in the output current. This would reduce the overall solar yield. No stand alone solar controller does this for obvious reasons.

 

[noelex]

Any idea if the Renogy Rover 40 is the same?

Most solar controllers warn that damage can result if the solar input is connected before the battery input or if the battery input is disconnected before the solar input.

The report from SeaChange in post #11 shows this is no idle warning.

Victron also recommended the same connection order, but state that their controllers have sufficient protection that no damage will result if this is not followed (although they caution the automatic voltage selection may be incorrect especially if this procedure is not followed for the first connection).

As a general rule, always connecting the battery terminals before the solar panel input (and vice versa for disconnect) is sound advice for any solar controller.

 

[Zing]

I had a HVC event. (Incorrect HVC cut off being set).The BMS shut off the controllers (Victron) before the panels. I subsequently lost the Victron bluetooth until a re-boot, but the controllers were undamaged. This is contrary to instructions. Just for info.

 

[PaulRainbow]

.

 

[PaulRainbow]

This depends on how the boat is wired. As you concede, some boats are wired such that the solar power is wired to the load terminals or downstream of the battery switch. This ensures that there is no possibility of charge or discharge from the battery if the main battery switch is off. It is not unusual.

I've never wired a boat in this way, as it's just plain wrong.

According to your previous posts, and indeed post #30, discoonecting the batteries will destroy the controller. Also, having a load connected to the contoller with the battery being connected can result in excess voltage damaging those loads. If wired as you describe above, turning the isolator disconnects the batteries, but leaves all of the loads connected to the controller output ! It would be a stupid way of connecting solar to a boat and is most certainly not usual.

These different wiring options are why I suggested in post #19 to check the circuit diagram to determine how your boat is wired.

You're seriously suggesting that i check to see how my boat is wired ?

There is no confusion: the Victron controllers on their own will continue the algorithm and supplying power to any connected loads once started even if the battery is subsequently disconnected.

A charge controller cannot distinguish between supplying current to equipment or to the battery.

If it did try to disable its output power in the middle of the day to see if a battery was still connected, it would necessitate a pause in the output current. This would reduce the overall solar yield. No stand alone solar controller does this for obvious reasons.

This is just more nonsense that you're making up as you go.

 

[PaulRainbow]

Most solar controllers warn that damage can result if the solar input is connected before the battery input or if the battery input is disconnected before the solar input.

The report from SeaChange in post #11 shows this is no idle warning.

SeaChange did not destroy a Victron controller.

Victron also recommended the same connection order, but state that their controllers have sufficient protection that no damage will result if this is not followed (although they caution the automatic voltage selection may be incorrect especially if this procedure is not followed for the first connection).

A link to these Victron instructions please ?

 

[Sea Change]

SeaChange does not have a Victron controller.

Actually I do, I have one Victron and two Epever.
I've killed one Epever already. When I reach a place where prices are sensible I will replace the remaining Epevers with Victrons...

 

[PaulRainbow]

Actually I do, I have one Victron and two Epever.
I've killed one Epever already. When I reach a place where prices are sensible I will replace the remaining Epevers with Victrons...

Gotcha, changed original post accordingly.

 

[PaulRainbow]

Victron MPPT controllers ( may also apply to other MPPT controllers, i only fit Victron) :

The only time you must connectthe battery first, so the controller can sense battery voltage, is during installation, the settings are stored and there is no need to disconnect the batteries first in future. The MPPT controllers don't care if there is a battery connected or not, they can be used to power loads using the load terminals, whether or not a battery is connected.

MPPT FAQ [Victron Energy]​

Q4: Can the output of the MPPT be used as a power supply, thus without batteries?​

The answer is; it depends on the type of load.
During low current situations the MPPT control bandwidth is too small to be able to maintain a stable voltage. The result is that loads that need to see a stable voltage before they can activate or loads that require a certain “under voltage” to active will not be able to run.
Loads where under voltage does not apply, like light globes, can be operated without any problems.