question

Hi, @DucksInARow

First of all 11.4 is a voltage sufficiently low as to damage your batteries. less than 12 on lead acids is discharged.

by run the engine I assume its a generator, or its a travel power alternator or similar as to have the float light on the quattro you'll have to be supplying AC power.

Without more detail its hard to say if an hour is sufficient to charge your batteries fully.

But reading between the lines, you don't say how big the quattro is, but assuming its a 3000 which is the smallest your batteries are smaller than the recommended lowest capacity. Table attached.

It also sounds like your using the bank as the domestic supply, in this case your further decreasing the available capacity in the batteries.

I recommend reading the 'energy unlimited' book as it will help you to understand some context.

The battery capacity is also related to the performance of the device when operating at higher loads. If the battery is too small you will be discharging it to quickly and get unsatisfactory battery life. You will also experience DC ripple and likely overload alarms a lot earlier than you would think.

Happy to help further but need

quattro model, size and voltage (I assume 12)

Loads dc and ac

alternator/generator type/size.

Do you have a GX device? Colour control, venus or cerbo?

Do you have a battery monitor?

If you can't figure it then just post pics of your engine, control panel and battery system and we should be able to give you some better guidance.

Thank you very much for such a swift response. Answers as follows:

Quattro 12v 3000VA 120 AmpN

Loads: 240v Ac, 12V DC

Dometic Travel Power powerbox/generator 3.5kw

GX device, etc? Not sure - I attach a photo of the Quattro if that helps.

What do you mean by a battery monitor?

Really appreciate your help - again, thank you.

@DucksInARow

Ok, so you have a travel power. I can only assume your input limit settings have been correctly programmed.

I'm afraid to say your battery bank just isn't sufficient for the loads your hanging off it hence your not getting though the night before you need to charge.

A GX device search Victrons website for 'CCGX' would monitor the system and allow you to make better decisions about when to start your engine to charge.

A battery monitor search 'BMV-702 Smart' would allow you to monitor your battery state of charge and alarm when you reach a low state of charge protecting the battery bank. - potentially shutting the quattro down to protect the bank from becoming discharged.

I would expect to see a bank of at least 600 Ah for a vessel of your type to get though the night.

Your set up would charge from flat (50% SOC) to 100% in approximately 3.5 hours engine running.

Sounds like your liveaboard, in this case it would be well worth exploring lithium batteries if you can afford them.

Hi just one extra thought.

Once the float light has come on you should stop your engine, not to prevent the batteries from being damaged, indeed if the float voltage is set correctly this should be no problem at all.

But in fact, during the latter stages of equalisation and the float stages there will be insufficient load on the engine and therefore the effect on engine longevity will be considerable. (Bore glazing and carbonisation)

Really the travel power system is designed to supply power when your travelling- motoring from place to place and the battery providing it when your stopped. When your moored for long periods, you should have shore power available in this model.

If your 'off grid' you might look at other sources of charging power to reduce your dependency on running the engine while moored, solar and wind are helpful in this regard. With careful consideration you might be able to reducing your engine running to twice/three times a week.

Have a look at the 'Journey with Jono' channel on you tube. He's been though exactly your conundrum on a narrowboat and there's a wealth of information there about victron gear aboard a narrow boat. - Plus some bonus content.

https://www.youtube.com/c/JourneywithJono/featured

I have tagged him in just for continuity.@Jono (Victron Energy Staff)

Hi @DucksInARow

Please confirm your battery type. Trojan T105's are 225 Ah at 6V, and 4x would be wired 2S/2P to give 450 Ah at 12V.

I use 8x (clones) at 48V, and agree 4x wouldn't be enough for a long winter's night at my modest ac needs. (I have another 6x at 12V for lights alone).

But to your Float question. It really isn't worthwhile running a generator in Float. It depends how it's all set up, but those are quite reactive batteries, and an hour in Bulk and another hour (say) in Absorb should suffice to bring you to maybe 99%. If you could see the battery Amps that'd be ~10A in your case.

Yes, you really do need better (well, more) kit to see what's happening if these things bother you. They bother me, so I'm not being critical.. :)