Inverter continuously charging

[Ratty69]

Hi all

I'm a new boater (insert groan) and lived on the boat for a month at its original marina on shore power with no problems. When cruising to my new home I had no power so arranged to see a spark when I got to the new marina. He checked all the batteries (6 x 100v) and said they were on their way out but not gone yet. I wasn't around when he checked them and when I got back to the boat, the inverter (pro combi s) kept continuously charging and then tripping the mains. Advised to get new batteries and these were fitted by another electrician (original one was booked up). A day later I have exactly the same problem. Can anyone advise please?

thank you :-) 

[WotEver]

If the charger is tripping the mains then one of the following is likely the culprit  

• The charger is faulty
• The mains supply is too small (perhaps only 6A?)
• There is a small leakage current somewhere on your boat (if it's the shore RCD that's tripping). 

So... what rating is your shore supply, 6A or 16A?  What is tripping, MCB or RCD?

it has nothing to do with your batteries. 

[Ratty69]

1 minute ago, WotEver said:

 

So... what rating is your shore supply, 6A or 16A?  What is tripping, MCB or RCD?

 

I've no idea ... where can I get this info (or is it just a case of asking the marina?) ... and I've no electrical knowledge at all so MCB/RCD means nothing to me. Laymans terms please :-/

[rusty69]

2 minutes ago, Ratty69 said:

I've no idea ... where can I get this info (or is it just a case of asking the marina?) ... and I've no electrical knowledge at all so MCB/RCD means nothing to me. Laymans terms please :-/

MCB=Minature circuit breaker. 

RCD=Residual current device. 

[nicknorman]

You are allowed to have no electrical knowledge provided you appreciate that we are not telepathic

Anyway, you say "tripping the mains" but you need to be precise about exactly what is happening and to what, where. A photo is worth a thousand words!

An MCB trips because too much power is being taken from the supply. An RCD trips because there is a leakage of current to earth, ie some bad wiring or bad equipment. Just to confuse the issue you can get combined MCB and RCD called an RCBO! No-one said it was simple! But if you show us a picture of exactly what is tripping, we'll probably be able to tell what it is. As has been said, the problem almost certainly isn't the batteries.

[WotEver]

The rating of the shore supply will be written on the MCB. It will say something like C16 or C6. The MCB is the 'switch' on the bollard that you switch up to turn the power on.

An RCD will have a 'Test' button on it.

You might only have the single breaker which combines the two. 

Cross-posted with Nick. Yes, post a picture of what's tripping. 

[Ratty69]

7 minutes ago, nicknorman said:

You are allowed to have no electrical knowledge provided you appreciate that we are not telepathic

Anyway, you say "tripping the mains" but you need to be precise about exactly what is happening and to what, where. 

As has been said, the problem almost certainly isn't the batteries.

Apologies ... I'm prone to rambling so was trying to be concise ;-)

Ta for the lesson - it's the MCB that's tripping (the "bollard").

Basically you all seem to be telling me that I've just spent £500 on batteries (as advised by 2 qualified bods) for no reason? Deep joy! :-(

[WotEver]

Just now, Ratty69 said:

Basically you all seem to be telling me that I've just spent £500 on batteries (as advised by 2 qualified bods) for no reason?

Probably not. Most boats appear to be sold with aged batteries at the end of their life. However that's irrelevant to your shore power problems. 

[Ratty69]

7 minutes ago, WotEver said:

The rating of the shore supply will be written on the MCB. It will say something like C16 or C6. The MCB is the 'switch' on the bollard that you switch up to turn the power on.

I will check this in daylight and confirm ... had presumed (clearly wrongly) that all shore power would be the same 

 

[WotEver]

Just now, Ratty69 said:

I will check this in daylight and confirm ... had presumed (clearly wrongly) that all shore power would be the same 

It may well be that your supply is 16A in which case the problem is probably going to be one of the other two suggestions I made.

[Ratty69]

I guess switching the power off would be the best plan for the night? Concerned that the continuous charging could create other problems - damage to new batteries/inverter? Not to mention a big elec bill!

Thanks for advice thus far guys - nice to know there are people out there willing to help :-)

[nicknorman]

Sorry to add to the confusion but the bollard "switch" might be an RCBO. All would be clarified if you could post a picture of it, and this will stop us potentially going down the wrong path. As to the batteries, yes chances are they would need replacing sooner rather than later anyway.

Can I also just clarify what you said in your first post "When cruising to my new home I had no power...". Normally one would expect the batteries to be charged whilst cruising so as to be able to supply any 12v services light lights and pumps, and the inverter would be able to supply mains power within reason. So what exactly do you mean by "no power"?

[nicknorman]

1 minute ago, Ratty69 said:

I guess switching the power off would be the best plan for the night? Concerned that the continuous charging could create other problems - damage to new batteries/inverter? Not to mention a big elec bill!

Thanks for advice thus far guys - nice to know there are people out there willing to help :-)

What do you mean by "continuous charging"? Normally one would expect it to take many hours to fully charge batteries that were low, and even then when they're full the charger will go into float mode so that it is still trickle charging the batteries, indefinitely. What is it that is making you think  "continuous charging" is a bad thing?

[Ratty69]

1 minute ago, nicknorman said:

Normally one would expect the batteries to be charged whilst cruising so as to be able to supply any 12v services light lights and pumps, and the inverter would be able to supply mains power within reason. So what exactly do you mean by "no power"?

Ok will post a pic in the am.

i had no power to sockets - lights were ok but all sockets were dead 

[Ratty69]

2 minutes ago, nicknorman said:

What do you mean by "continuous charging"? 

Sorry - bad terminology. I mean it's on fast charge permanently. The inverter was (previously) silent but now sounds like a fan heater on full tilt!

[WotEver]

Photos of the inverter/charger and new batteries as well please. 

[nicknorman]

24 minutes ago, Ratty69 said:

Sorry - bad terminology. I mean it's on fast charge permanently. The inverter was (previously) silent but now sounds like a fan heater on full tilt!

Ok but as I said, it can take quite a long time to fully charge a bank of 6 batteries. If the charger is working hard, the current is going somewhere either:

-charging batteries that are not yet fully charged

-Running 12v services on the boat (e.g. lots of lights switched on)

-overcharging the batteries due to some fault. This causes the batteries to fizz, converting water into hydrogen and oxygen, and to get warm. I'd check the batteries to see if they are fizzing excessively, or warm. Check each one.

If any are warm, definitely turn off the charger.

Anyway you have discovered that life in a boat isn't as simple as in a house! Can I suggest that you really need to acquire some electrical knowledge as if you get an electrician out every time there is a hiccup, it's going to get very expensive. (I guess perhaps this is what you are trying to do here though!) Especially as there are lots of incompetent cowboy boat electricians out there (they don't need any qualifications to call themselves an electrician, to start with!).

Electricity is invisible and you need measuring equipment to be able to see what is going on. Many folk including me have a UNI-T UT203 clamp meter costing £30 or so from eBay. It is good for measuring voltage and current, so instead of guessing you will be able to determine what is going on with the charger etc. Before you say "but I don't know how to use one" can I point out that if you don't have one, you definitely won't be able to use it. If you get one, you can probably learn/have someone show you how to use it. But getting one is the first step.

[Ratty69]

2 minutes ago, nicknorman said:

Ok but as I said, it can take quite a long time to fully charge a bank of 6 batteries. If the charger is working hard, the current is going somewhere either:

-charging batteries that are not yet fully charged

-Running 12v services on the boat (e.g. lots of lights switched on)

-overcharging the batteries due to some fault. This causes the batteries to fizz, converting water into hydrogen and oxygen, and to get warm. I'd check the batteries to see if they are fizzing excessively, or warm. Check each one.

If any are warm, definitely turn off the charger.

Anyway you have discovered that life in a boat isn't as simple as in a house! Can I suggest that you really need to acquire some electrical knowledge as if you get an electrician out every time there is a hiccup, it's going to get very expensive. (I guess perhaps this is what you are trying to do here though!) Especially as there are lots of incompetent cowboy boat electricians out there (they don't need any qualifications to call themselves an electrician, to start with!).

Electricity is invisible and you need measuring equipment to be able to see what is going on. Many folk including me have a UNI-T UT203 clamp meter costing £30 or so from eBay. It is good for measuring voltage and current, so instead of guessing you will be able to determine what is going on with the charger etc. Before you say "but I don't know how to use one" can I point out that if you don't have one, you definitely won't be able to use it. If you get one, you can probably learn/have someone show you how to use it. But getting one is the first step.

Currently have a fridge, freezer (a luxury that I don't need so is soon to be gone), and a Tv on with no lights or anything else electrical running. None of which were problematic before now. 

As I'm not keen on crawling into the engine bay in the dark, I'll switch off the inverter for the night (I'll not sleep for worrying if I don't anyway).

I take your point about a clamp meter and I'll get one toot suite together with finding someone to give me some basic tips on maintenance. I'm just particularly nervous when it comes to electrics - which isn't necessarily a bad thing is it?

You're right, life's not so easy but I'm just at the bottom of that learning curve so, hopefully I'll start making my way up it in time. 

:-)

 

[nicknorman]

50 minutes ago, Ratty69 said:

Ok will post a pic in the am.

i had no power to sockets - lights were ok but all sockets were dead 

We don't yet know exactly which inverter/charger you have but quite likely, it should automatically switch over to inverting to power the sockets when shore power is unplugged. Some such devices have a switch that allows you to select automatic operation, or charger-only operation. Maybe your device is set to the latter. This is a good thing when you are in the marina, but if you go cruising again you need to put it to automatic to get the sockets working from battery power.

From what you've said, it sounds like the first electrician was pretty clueless, which unfortunately is not uncommon.

[Ratty69]

Before I sign off to get some sleep here are a few pics as requested. Battery and shore power bollard to follow in the light of day ... All of the following are internal and yes I did switch from shore to domestic whilst cruising ... night night peeps :-) 

 

[Robbo]

Do you have anything else on when it trips, like electric kettle or have your immersion on?

that charger should go into "charger in float" mode after a while (may be minutes, may be 9 hours depending on how flat your batteries are).

 

My guess is that you have a immersion on which is a high wattage which is tripping the shore power, this then drains the batteries quickly.  The immersion may even be on a timer just to confuse you!   You could drain the batteries in 30 mins and it would take around 5-9 hours to charge them back again.   You may be just in the limit of it shore tripping so it may not trip 90% of the time until some the fridge decides it needs to come in so the tripping may seem random as well.

 

Things to find out;

how many amps the shore power can supply (from Marina), or if you share between other boats.

if your immersion is on and the wattage if so.  If it's on or via timer, turn off and then see if we trip again.

if your using any other high wattage device, kettle, electric heater, or microwave?

 

 

 

 

Edited April 12, 2017 by Robbo

[by'eck]

Hi Ratty,

Two questions: Have you tried a different mains socket on the bollard as they each have their own breaker?

Have you ensured that all mains devices are turned off other than the Sterling Combi? This would include immersion heater and any other mains device supported by the Combi, mains fridge for example.

It's not apparent from the photo which Sterling Combi model you have, but the largest version has a 100 amp charger and can give more. This means it takes a fair amount of power from the shore supply which when added to that supplying other devices may trip an over sensitive breaker. 

Finally by way of advice, always turn the Combi off when shore power not present and you don't require AC on board. Failing to do this will mean the charger is regularly working flat out to re-charge batteries, which I suspect is contributory to your problem. 

If it's any consolation, I had virtually the same issue when using my own Sterling Combi.  Having tripped the shore breaker by being a numpty and adding an electric kettle to the load, I didn't notice the inverter on the Combi had take over, consequently batteries were drained a little. Had to switch all other AC loads off to avoid tripping the sensitive 16 amp breaker again when I realised the problem -  CombI was putting 110 amps into batteries for a while!

[Ratty69]

Having just had a hunt for the immersion heater (and yes I can hear you all sighing and saying "she doesn't know where it is?!") I've just discovered that the washing machine was switched on. Odd because I've never used it (but I have had 2 small boys on the boat for a day so possibly one of them was playing around) but I guess that could be a contributory factor. 

Yes I did try both shore breakers and both did the same. I'll see if the problem resolves itself now the washer is off.

Numpty points 1 : Ratty 0

Thank you all for your advice you lovely lot :-) 

[Robbo]

Unless the washer was going it's unlikely to be the cause.   Did you find the immersion heater,  the switch for it will be near the calorfier (ie. hot water tank).    How do you get hot water on the boat?

[nicknorman]

Morning! So yes, you'd expect the "fast charge" light to go out and the "float charge" light to come on, but it might take many hours for that to happen. Maximum 12 hours, according to the spec. It decides when to go into float based on the current it is being asked to supply. So if just to the batteries, then it will go to float once the batteries are fully charged and stop taking significant current. However if boat 12v services are on (lights, 12v fridge etc) the Combi can't distinguish between current going to the batteries and current going to those services, so the switch to float will be delayed. This isn't a problem. I note you have the Combi set to battery type 4 which is 14.4v, and normal batteries can happily spend 12 hours or more at that voltage without any issue.

To address the prolonged fast charge issue I don't think we are going to get far until we know what the current and voltage going into the batteries is. But I would be inclined to leave it charging for up to 12 hrs to see if it eventually goes to float.

To address the breaker tripping, the general idea is to switch everything off, then switch things on individually to see if any one device causes a trip. If it only trips when multiple mains devices are turned on then it might simply be that you are trying to take too much power from the shore bollard.

The other thing to bear in mind is that if the shore bollard trips, the Combi should automatically switch over to inverting, ie providing mains power by taking charge from the batteries. Depending on what you have switched on, this can drain the batteries significantly and then of course when you restore shore power, the battery charger will have to work hard to replace the used charge.

Most inverters have a switch to make them be a charger only, ie not go into inverting mode, but I have a feeling that yours doesn't (someone who has one might confirm?) so you are at risk of flattening the batteries if the shore power trips and you don't notice. Where do you have the red rocker switch on the remote control panel at the moment?