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**noelex 77** · 17-09-2019, 12:54

Quote:

Originally Posted by BigAl.NZ

Are you suggesting for boats with multiple charge sources the tail current is best switched off? (We have Alternator+Solar)

I would caution that it is early days. This firmware makes the controller perform very differently, so it will take some time to deduce the best settings.

My current recommendation would be if you have multiple Victron solar controllers or one Victron solar controller and a smart alternator controller, then I would select the “disable the tail current” option. This would also be my recommendation if you have wind or hydro power available.

If you have a simple alternator regulator with a single solar controller (with no wind or hydro) I would leave the tail current on the default setting.

The absorption time setting will need to be checked and probably adjusted with the new firmware, but this applies even if no change is made to the tail current setting.

Quote:

Originally Posted by BigAl.NZ

Does the new FW allow the SC to communicate with a BMV712 on the same network?

Sorry I don’t have a BMV712 so I cannot help with how the new firmware performs with these extras. I am sure someone else will know.

swampbush · 17-09-2019, 13:08

Quote:

Originally Posted by john61ct

Does this change allow all the SCs to drop to Float based not off their individual tail current readings, but the centralized one reading **bank acceptance** off the BMV shunt?

No, but Victron have said it is being worked on for future releases using Bluetooth networking between the bmv and mppts.

john61ct · 17-09-2019, 13:18

Presumably via wired protocol as well then.

The only think I would rely on BT for is noncritical stuff between my phone and a nearby gadget

swampbush · 17-09-2019, 13:43

Quote:

Originally Posted by john61ct

Presumably via wired protocol as well then.

The only think I would rely on BT for is noncritical stuff between my phone and a nearby gadget

I have used it for voltage sensing for a year now, mppts gets voltage directly from the bmv voltage sense wire at the battery, so not affected by current. Bluetooth failure sees it revert to standard voltage sensing from the mppts. Zero risk except possible slight undercharging.

john61ct · 17-09-2019, 14:38

Yes, just meant me, personally, I prefer hard-wired comms protocols.

BigAl.NZ · 17-09-2019, 16:48

Quote:

Originally Posted by noelex 77

I would caution that it is early days. This firmware makes the controller perform very differently, so it will take some time to deduce the best settings.

My current recommendation would be if you have multiple Victron solar controllers or one Victron solar controller and a smart alternator controller, then I would select the “disable the tail current” option. This would also be my recommendation if you have wind or hydro power available.

If you have a simple alternator regulator with a single solar controller (with no wind or hydro) I would leave the tail current on the default setting.

The absorption time setting will need to be checked and probably adjusted with the new firmware, but this applies even if no change is made to the tail current setting.

Sorry I don’t have a BMV712 so I cannot help with how the new firmware performs with these extras. I am sure someone else will know.

Yeah I think I will leave mine at 1A (about 0.7% of Ah) since most of the time the MPPT is keeping batteries in float when not on boat. Different story when the engine is going.

I have the Balmar MC614 - but I dont know of any alternator regulators that exchange data with MPPT controllers - are you saying there are alt regulators that do this?

john61ct · 17-09-2019, 17:55

No, other than FOSS projects

but a BM like BMV-712 relay based on SoC can take the bank offline from the alt, or stop the power input to the VR.

**noelex 77** · 18-09-2019, 00:10

Quote:

Originally Posted by BigAl.NZ

Yeah I think I will leave mine at 1A (about 0.7% of Ah) since most of the time the MPPT is keeping batteries in float when not on boat. Different story when the engine is going.

When the boat is unused with no loads on the battery, the tail current feature of the solar controller can be useful, so in your case the idea of keeping the Victron with a 1A tail current setting is sensible.

Try and have the alternator absorption voltage a little bit below the solar absorption voltage if the tail current is enabled on the solar controller. This is easy to do with the Victron solar controllers because the voltage set points are adjusted in very fine 0.01v steps.

The problem with setting the alternator regulator at a slightly higher voltage than the solar controllers (and this can occur even if the setting on the two devices is numerically the same) is that the current from the solar controller will often drop below the 1A level when the alternator is running. The solar controller will therefore drop back to float. This is not ideal if the batteries are reasonably discharged and the alternator run time is short.

Quote:

Originally Posted by BigAl.NZ

I have the Balmar MC614 - but I dont know of any alternator regulators that exchange data with MPPT controllers - are you saying there are alt regulators that do this?

The important current is the amount entering the battery. Ideally to control the charging correctly this number needs to be known by controllers/regulators. Solar controllers and alternator regulators normally only know their current output. They have no idea how much of the current they output is going into driving loads, how much is entering the battery or how much current is being produced by other charge sources. This is why default settings such as the tail current can cause problems. Boats are unusual in having so many charge sources.

There are devices that will tell the solar controller how much current is entering the battery. This can be enabled on many of the better solar controllers, but it involves extra equipment (and expense) and not many boats have this level of sophistication, although this is changing as marine electric systems are becoming more complex.

The ultimate solution is to share and integrate the current entering the battery with both the solar controller, alternator regulator, battery charger as well as wind and hydro generation if fitted. This level of development is just becoming available, but this type of system is very complex and introduces the possibility that a single failure point could disable all the charge sources.

On my boat I have a simple system of three solar controllers (linked to three seperate solar panels) and a smart alternator controller. None of these devices are linked so each tries to do its own thing when charging the battery. A system such as this has very good redundancy and reliability. As a bonus it is inexpensive, but it needs some care to charge the battery correctly. The default settings are not generally ideal. The added adjustability now available with this new firmware is a significant help.

GRIT · 18-09-2019, 08:33

The new firmware doesn't seem to be available in Canada, yet. Has anyone, in Canada, downloaded the new firmware?

Electrons do seem to flow more slowly up here, as regards the internet.

Cheers.
Paul.

Mike OReilly · 18-09-2019, 09:26

Quote:

Originally Posted by GRIT

The new firmware doesn't seem to be available in Canada, yet. Has anyone, in Canada, downloaded the new firmware?

Electrons do seem to flow more slowly up here, as regards the internet.

Cheers.
Paul.

I did. Came through fine.

admiralslater · 18-09-2019, 09:45

This is a great discussion as I had a premature float issue last year . I my question would be and excuse my ignorance , I have 5type 31 FF batteries is the tail current for the bank 1.5amps or is it 1.5 amps per battery so 7.5 amps .
This float business really had me pulling my hair out last year ( not a good look)

GRIT · 18-09-2019, 11:14

Thanks Mike, I'll try again.

john61ct · 18-09-2019, 11:45

Yes C-rate is proportional to Ah capacity so for 500Ah endAmps is 7.5

FlyingScot · 18-09-2019, 12:29

I just upgraded all 4 of my 100/30's from 1.39 to 1.42. I see the change of settings.
I'll watch and see how they perform. I saw the default is 2 amps. I left it there for now. One of my controllers already dropped to float. My house bank is 100% SOC right now.

So far it acts in a similar way as all previous versions, one or more drop to float while the others provide the house load and keep a positive amount of amps going to the battery.

For those who have a BMV-712 that already had a tail current setting to determine when the battery is listed as 100% SOC. The BMV setting is a percentage of bank size vs. the SC allows direct entry of tail current amps.