Inverter / Charger Issues

[2020Vision]

Hi

I have a problem with my boat electrics. The inverter won't work and the 240v electrics don't work on shore power and it seems the inverter is tripping out and therefore the batteries are not getting charged from shore power. I was an auto electrician for 30 ish years so I understand electrics fairly well. I am struggling to understand all the components involved, there ais a Cyrix-ct and a 3 battery Agoi Fet diode pack, also n alternator regulator. I can't ascertain which unit or units will cause the Inverter to trip.

Any help welcome please

[Vaughan]

I think you need to describe the circuit a bit more before we can be of much help.

The 240v electrics may not be wired direct to shorepower but rely only on the inverter.

The intelligent regulator parts should not have anything to do with the inverter.

Do you think that maybe the inverter is tripping out because it has no ventilation, and is overheating?

Does the inverter have its own bank of batteries, separate from the domestic batteries?

[BroadAmbition]

Process of elimination required here (Just been through something similar mysen)

First off, disconnect the inverter out of the equation then see if your shore power stays on.  If it does is it charging the batteries?  If so then it's obviously an inverter issue = change / repair the inverter

There are other steps to follow of course

You might wanna glance at our 'Broad Ambition TLC' thread go back a few pages to see what we went through, it might give you some ideas

Griff

[2020Vision]

Thank you for repling

There are 2 banks of batteries. When the fault first occurred I found out that one bank of batteries were below 10v, I thaought that this may cause the inverter to trip. As they were connected in parallel I decided that if I put one known good battery back in their place it would show that the dead batteries were the issue. But the fault is still apparent.

I am not sure if the inverter does actually charge both banks or if the faulty bank is only charged by the engine running.

 

[Vaughan]

If your batteries were below 10v, they are dead.  There was also something in your circuit that killed them!

You mentioned various electronic charge splitters and regulators, so best to determine that all your batteries are getting a charge from the engine.

Inverters (also fridges) will cut out if the voltage is too low.

Remember that at 12.7 volts a battery is charged.  At 12 volts it is half charged.  At 11.5 volts it is effectively discharged. Anything below that - it is probably dead.

[2020Vision]

As I've put a known good battery 12.7 v in I would have thought that  it would eliminate the bad battery issue.

Also I've bypassed the the inverter and connected shore power straight through and the boat's 240 v is all ok.

A couple of things puzzle me, why have a Cyrix battery combiner and an Argo Fet isolator. Would the failure of batteries cause the Inverter to disconnect the boat's 240v circuits?

 

[Vaughan]

I have googled the Cyrix and the Agoi Fet.  Both made by Victron, one is a battery combiner and the other a charge splitter. Sounds like what they use in camper vans but I have not come across them in a boat before.

Why do you need both, as they both do the same job, but in different ways?

The third box is an intelligent electronic regulator which is supposed to give a more efficient long term charge.  There are opinions for and against these - I don't use them myself.

If either of the Victrons have failed, this will be the cause of your problem.

If you also have a shore power 240 volt battery charger with 3 outputs - for starter, domestic and inverter batteries, it sounds to me as though your circuit could be usefully simplified, to make it more reliable.

[2020Vision]

Thank you for your thoughts on this.

II think that the bank of 3 failed batteries was was to power the inverter when out on the river so I might put a seperate charger on those when I replace them. These I can manually switch to charge when on shore power and use the alternator to charge them when no shore power, what do you think?

[Vaughan]

If you have 3 batteries to power the inverter it must be a powerful one.   Does it run a microwave?

We still have the problem, that your batteries were down to below 10v.  You need to make certain that all these little electronic black boxes are actually giving a good charge to all your batteries when the engine is running.

3 inverter batteries maybe also also mean 3 domestic batteries?  In which case you may consider fitting 2 alternators and running the inverter as a separate circuit.

[2020Vision]

Unfortunately I can only get to my boat every fortnight or so. I'm thinking that it has been working ok for me for about 3 years and then lockdown came in and it was left for 6 - 8 months during which time it has failed so the current configuration is ok but a component has failed probably as you say one of the split charge / isolator units.

I need to try and find out what the switch on the inverter actualy does and if I should switch it to charge only when I leave the boat for any length of time and when it's switched to inverter - is it still supposed to charge the batteries? Thank you you've given some ideas and little more insight into where to start testing.

[Bikertov]

Whilst I don't have direct boat electrics experience, I would suggest checking the voltage of each battery when disconnected from the others rather than the bank as a whole.

Often (with car batteries for instance) individual cells within a battery die, so bringing the voltage down. It maybe that just one battery has gone rather than all of them.

That might indicate if it the batteries or the 'black boxes' that are the problem.

 

[Vaughan]

An inverter simply converts DC current to 240v AC and if it is running something like a microwave it needs a lot of battery capacity to provide the power.  Hence Richardsons always say you must run the engine while using the microwave, so that the alternator can compensate for the power being used.

The inverter does not charge the batteries from shore power.  You need a battery charger for that and I recommend at least 40amps DC output.  They can be bought with 2 or 3 separate outputs.

[2020Vision]

Thank you for all your help. I'll do more tests the next one I go to my boat. Probably get back to you then

[Vaughan]

As we are talking about inverters, it is worth a general warning about earthing.  Basically, 240volt AC and water do not mix.

All shore power circuits must be earthed back to the shore by the third wire in the cable and 240v circuits must never be earthed to the return side of the 12v DC circuits.  On almost all boats this means it must not be earthed to the engine either.

The inverter provides a 240v circuit in the boat, where appliances can still be plugged in, when not on shore power, so this circuit must be earthed as well.  This must be carefully thought out and really should be done by a qualified electrician.

The latest types of inverter do not require an earth and several modern appliances don't either but the problem with that comes when you plug something into the circuit that does require an earth. This particularly applies to hot water immersion heaters. These often fail owing to corrosion from the water and if your boat has copper piping, then that is where a current leak will earth to. Not much fun if you are having a shower at the time!

Please be very careful when installing inverters on a boat and it is always best to have it done by a professional.

[annv]

Leaving battery's for eight months with out a maintenance charge while kill battery's, and once they are discharged modern battery's cant be recharged. John