DC -DC charger on

Any reason why my portside DC -DC charger was on this morning? Engine was off. I Have detect engine off checked. Was at 100% plugged into shore power and I noticed the charger on bulk. Is there any reason why that would be? It’s usually off if the engine is off

Really need a lot more information here, but if you’re using the engine run detection verify the voltage is set appropriately. If it is set too low the charger could kick in inadvertently, if the voltage is indeed set above the resting voltage of the starting battery and the unit still turns on randomly, you probably have an issue with the charger

I’m basically using the default settings.
I’m not sure what information you need but here goes
I have 3000w solar array
4x 330ah lifepo4 batteries
5k 12v quattro
5 x 100/50 mppt
2 x 30 amp DC -DC ISO chargers
2 battery protects
Cerbo GX
BMS bus
Smart shunt
All victron
Had the system for about 3 years and never seen the DC -DC charger on unless the engine was on but this morning while cleaning the engine bay I noticed the port side charger was hot so I checked the victron app and batteries was at 100% on shore power and the port side DC -DC charger was on. Checked all the settings everything was correct. It stayed on for about an hr on bulk but everything else was on float.
Checked it again around an hr later and it was off.
Today went out for a test drive and everything was back to normal. Went on while engine was running and turn off when I shut off the engine
Just worried because we added Quattro about a month ago and had an issue with the installer crossed the neutral and load wires. Luckily I checked his work and noticed it.

Ok so you were connected to shore power if I read that right?

What are your voltage settings for engine detection? I’d make the assumption that the Quattro was charging and voltage was high enough to turn on the dc-dc charger

Yes was connected to shore power and 100%. Everything was on float except the port side DC -DC charger was on bulk. Here’s the settings

Do you have a starter battery charger connected via shore power or PV? This could raise the starter battery voltage enough to fox the DCDC into thinking that the engine is running.

Victron DCDC chargers also give you the option to trigger them via a hardwired ignition connection instead of the software based engine detect system.

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I’m not sure how it’s connected. But either way why would it be on bulk if batteries was at 100% and everything else was on float?

Well, if the starter battery is above 14v the charger will start working, thats how its programmed..

You could inhibit this by connecting the “h” terminal to ignition, leaving the l terminal unconnected.

But pls also post the charger page of the programming, as you write, it shouldn’t be in bulk.

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Here is the charger page

Who or what is responsible for SoC ?

VE BMS bus and the Quattro

Ok, go buy yourself a smartshunt and you’ll get reliable numbers.

I do have a smart shunt. I thought you meant what I’m using to shut down on soc

Is the smartshunt responsible for your soc, or the bms, or the multiplus ?

The smart shunt

Then pls post the settings of the smartshunt and the chargers

Here’s the settings of the smart shunt and both DC -DC chargers

(attachments)




Ok,

In the chargers, set the absorption time to 10 hours.

In the smartshunt set charged voltage to 14.0

And the tailcurrent to 0.5%

Then rest the SoC to 50% manually and start a new cycle by switching the chargers off/on .

In one week you can set the absorption time back to. 3 hours…if you like.

Ofc also check the charger data of mp and mppt, must be identical.

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Here is a WAG for you. Perhaps your shore power voltage had a temporary increase. The docks can have significant variation in voltage. The factory charger(s) on the boat may have seen a large enough voltage difference between shore power and starter battery to start charging the starter battery. Then the starter battery voltage increase, while being charged, caused your DC-DC to start charging. PS: DC-DC are always too hot to touch when charging. Notorious design feature.