Considering Joining A Syndicate At Some Point

[oldgregg]

I think the voltage cutoff is definitely too low, 10V equals batteries being toast.

I remember reading the manual for the inverter and thinking it was pretty prehistoric.

The biggest problem with that boat is that owners aren't putting in as much charge as they're taking out.

It needs a second alternator and owners should be plugging into shore power whenever they see it - But also the domestic electrics need to be set up so that they shut off if voltage gets too low.

People just don't understand electrics so the system has to manage itself.

[grendel]

All the above assumes the batteries are Lead Acid, there is now an alternative in Lithium Iron Phosphate, these can be discharged to almost 0% (so a 130Ah battery can supply 130Ah) and have a higher number of charge cycles, they do need the alternator output to be changed, though its better to go via a charge monitering circuit as they can accept the charge much faster than lead acid, and without a charge regulator they can destroy alternators by demanding too much power from them.

with these wonder batteries being out there, why isnt everyone using them, - its simple they cost an awful lot more than lead acid- eg over £500 for a 130Ah 12V

[oldgregg]

The boat has AGM batteries, quite a lot of them.

Three for domestics, two for inverter and two for engine / thruster.

I can't remember which bank the fridge runs from, but it's a large one and uses quite a lot of juice so the charging needs are not inconsiderable.

[Vaughan]

26 minutes ago, oldgregg said:

Three for domestics, two for inverter and two for engine / thruster.

I can't remember which bank the fridge runs from, but it's a large one and uses quite a lot of juice so the charging needs are not inconsiderable.

The amount of batteries sounds right to me (without knowing what equipment is being used) so I don't think it is that which is killing the batteries.

I agree with having 2 starter batteries, to supply the thruster as well, as both starting and thrusting are bursts of high power but only for a few seconds, so the batteries will rapidly re-charge.  They are also only used when the engine is running.

A 160 litre marine fridge with freezer compartment on 12 volts will still only use about 80 watts, and not all the time.

An inverter is simply converting the power requirement from 12v DC to 220 AC.  The power still has to come from somewhere!  An 800 watt rated microwave is actually using over 1000 watts of current, which is coming from the batteries, so that means 83 amps on 12 volts plus a coefficient of about 10% for the inverter itself.  If you have a microwave, cooking for 5 or more minutes at that rate, the batteries are not going to support it, and I don't blame them!

So I suggest the answer to your problem is : only use the microwave when (a) the engine is running or (b) when it is plugged direct into shore power by a separate plug circuit.

I also suggest you cannot expect the batteries to support, on their own, the running of a hot water immersion heater.  This too, should be shore power only.

Let's keep things simple, on a boating holiday!

[Matt]

Thanks all.

 

Fridge runs off the domestic batteries and the immersion heater is shore power only.

As @oldgreggeludes to people have a perception that syndicate boats are well used every week and to an extent they are but Thunder at least doesn’t seem to go far! The engine hours suggest under 4 hrs a day cruising on average so getting the charge into the batteries can be a problem. The 240volt side just seems to be a bit of a problem side at the moment.

 

She has a Victron Atlas 12/1600 inverter which is from her hire days, so over 11/12 years old. 
 

 

[NeilB]

1 hour ago, oldgregg said:

The boat has AGM batteries, quite a lot of them.

Three for domestics, two for inverter and two for engine / thruster.

I can't remember which bank the fridge runs from, but it's a large one and uses quite a lot of juice so the charging needs are not inconsiderable.

Is there a charge regulator fitted for AGM batteries or just the standard one for lead acid as this can cause issues with shortening the life of AGM batteries?

I'd also check the inverter specs as 2 batteries may be below the recommended amount and adding to the issue.

[annv]

Hi Unless you have a intelligent charging system on a multi bank battery pack the battery's will rarely get fully recharged which reduces the battery's life cycle. I use four lead acid 110A battery's in one bank and get three years use before they need replacing , they do get checked for electric-lite levels so some maintenance is necessary. Battery's also need to be kept fully charged before being left standing, a solar panel is very good for keeping them in a fully charged condition when boat not used. John

[webntweb]

22 hours ago, Matt said:

She has a Victron Atlas 12/1600 inverter which is from her hire days, so over 11/12 years old. 
 

 

If that is the same one that was in Lightning, and I presume it will be as they were built at roughly the same time, it had a peculiarity: It was 1600 watts but it only output in blocks of 400 watts, so if your item only needed say 100 watts it somehow drew 400 watts. We found this out because a cpap that only needed 70 watts would not work all night - an almost full battery would be flat by morning.

[oldgregg]

3 hours ago, webntweb said:

If that is the same one that was in Lightning, and I presume it will be as they were built at roughly the same time, it had a peculiarity: It was 1600 watts but it only output in blocks of 400 watts, so if your item only needed say 100 watts it somehow drew 400 watts. We found this out because a cpap that only needed 70 watts would not work all night - an almost full battery would be flat by morning.

Yes I believe it's exactly the same one, I think Thunder was offered the old one as a spare when Lightning were upgrading.

That's a very interesting piece of information, though. I would think a lot of Thunder owners use the TV, which is a 240V model running off the inverter. So 3-6 hours of 400w a day is not going to do the batteries any good at all.