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Charging flat leisure batteries


Katie

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Just picked up my first boat. Has been sat unused for a while and leisure batteries and flat. I understand will take a long time to charge them backup from the engine but was wondering if this has to be done in one sitting or if I can do it by running the engine for few hours each day without using and power on board during/between that time. 
 

so far I’ve run the engine for about 3 hours today and still barely any charge to run the lights. Is there any point continuing to try or are they likely dead and need replacing? 
 

worth pointing out that in confusion over the system I managed to run the starter battery flat, using that as a power source over night. So I jump started it today and ran engine for 3 hours to try and charge starter and try and get some charge back into leisure batteries. Starter seems fine but still no leisure battery power. 

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9 minutes ago, Katie said:

Is there any point continuing to try or are they likely dead and need replacing? 


If they can barely power the lights after 3 hrs engine running they are almost certainly dead and will need replacing. Lead acid batteries do not take kindly to being left in a discharged state for an extended amount of time. 

 

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No battery monitoring or auto charge relay no. Just a selector switch for shoreline or battery power. 
 

so not really worth me running her for a few hours again to see If I can get any charge? Alternative option is to remove batteries and try putting them on charge from mains power. 
 

 

 

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8 hours ago, David Mack said:

What do you have in terms of battery monitoring? And do you have an automatic charge relay, or are you reliant on 1-2-both-off switch to determine which batteries are in use or charging?

Lights, especially if they are LED ones, can still illuminate with virtually dead batteries. It is possible that the house batteries are not actually being charged. Perhaps down to a faulty automagic charge relay, or a dodgy 1-2-both switch, or a duff connection somewhere. The most likely problem is that the batteries are wrecked and can barely hold any charge. The longer they are not being charged for the more wrecked they will be, but if there is still a problem getting charge to the batts, then the new ones will quickly get wrecked too.

 

2 minutes ago, Katie said:

No battery monitoring or auto charge relay no. Just a selector switch for shoreline or battery power. 
 

so not really worth me running her for a few hours again to see If I can get any charge? Alternative option is to remove batteries and try putting them on charge from mains power. 
 

The selector switch for shoreline, or battery power is a mains selector switch, not 12V DC. Do you have a mains battery charger, or a combi inverter charger on board and either a shore lead bollard connection, or a generator? If so, then trying to charge the batteries up from this is worth trying. Without having something to measure battery voltage and current going in to and out of the batteries you'll have no idea if the batteries are actually being charged, or not. Removing  them and charging them via a mains charger is a faff, but worth doing. Do you know how to safely remove battery cables?

Do you have any knowledge of electricity or not? Either way, it is worth reading @Tony Brooks notes on boat electrics. They should give you the basics. His notes from the courses he used to run are very useful for a new boat owner.

Jenny

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19 minutes ago, Katie said:

No battery monitoring or auto charge relay no. Just a selector switch for shoreline or battery power. 
 

so not really worth me running her for a few hours again to see If I can get any charge? Alternative option is to remove batteries and try putting them on charge from mains power. 
 

 

 

 

Without voltages, we don't even know if the alternator has sufficient output voltage and if it has its getting to the batteries.

 

I think you may be confusing the 240V AC circuits and control with the 12V DC charging. The first sentence sounds like selecting between inverter provided AC or shoreline AC so it's not relevant. This means that if its a single alternator engine you must have some form of charge splitting and that is another potential "stopping the battery charging" point.

 

If you don't have  a multi-meter or don't know how to use it then try the following but I suspect the batteries have probably had it.

 

1. Does the charge warning lamp come one when you turnt the ignition on and go out as the engine  revs and then stays out until you stop the engine?

 

2. If your battery master/isolator switch(s) use a removable plastic key take the key(s) out and put a ball of paper or plastic film down the hole and reinsert the key. If that seems to help, the switch(s) need changing for a better quality one.

 

3. Taking exceptional care not to let a spanner touch the battery terminal and any adjacent metal turn the master switches and all electrical equipment off and take the battery terminals off. Negative first, then positive. Clean the mating surfaces to bright metal and then refit. Pos first, the neg.

 

That should rule out the more common causes of your problem, but I still suspect batteries.

 

PS - thanks for the plug Jen.  Katie feel free to ask questions here or directly to me via email if you feel asking them might make you look silly. It won't, the silly ones are those who don't ask.

Edited by Tony Brooks
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20 minutes ago, Katie said:

No battery monitoring or auto charge relay no. Just a selector switch for shoreline or battery power. 
 

so not really worth me running her for a few hours again to see If I can get any charge? Alternative option is to remove batteries and try putting them on charge from mains power. 
 

 

 

 

If they have been left 'flat' for several weeks you are very unlikely to be able to get the to hold any charge, instead of wasting money burning diesel to try and charge them you would be better buying a set of new batteries.

 

You also need to invest in, and understand how to use battery monitoring equipment otherwise you will be in the 'same boat' again in a few weeks.

You must keep the batteries charged, on an average boat you would probably need to run the engine 3 or 4 hours a day and then 8 hours at weekends to keep the batteries topped up.

 

Battery charging and usage is one of the most complicated things for new boaters to 'get their head around'. You are now not only a user of electricity, but are the power station generating it as well.

If you have a shore-line available leave it plugged in and (assuming you have a quality multi-stage charger) leave the charger on permanently.

Edited by Alan de Enfield
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Thanks all really appreciate it. I don’t understand electrical stuff at all really (clearly) 

 

yes batteries seem to have been left flat for several weeks so I’m guessing they are just dead. 
 

alternator light on ignition goes off after engine started and key turned back. Only way I can get any power is to keep Key turned, but seems this is using starter battery to power 12v systems? 
 

I can get hold of a generator and have a charger on board used when hooked up to shoreline. So guessing I could just plug that into the generator and see if that manages to charge? 

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16 minutes ago, Katie said:

Thanks all really appreciate it. I don’t understand electrical stuff at all really (clearly) 

 

yes batteries seem to have been left flat for several weeks so I’m guessing they are just dead. 
 

alternator light on ignition goes off after engine started and key turned back. Only way I can get any power is to keep Key turned, but seems this is using starter battery to power 12v systems? 
 

I can get hold of a generator and have a charger on board used when hooked up to shoreline. So guessing I could just plug that into the generator and see if that manages to charge? 

Why are you turning the "key" off after you have started the engine? It will stop the batteries from charging!!!!

Would you turn the ignition off on a car after starting and expect it to work?

 

Is there another boater near who could show you how to run your engine and charge the batteries?

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1 minute ago, Tracy D'arth said:

Why are you turning the "key" off after you have started the engine? It will stop the batteries from charging!!!!

Would you turn the ignition off on a car after starting and expect it to work?

 

Is there another boater near who could show you how to run your engine and charge the batteries?

He could mean that he turns (releases) the key back from start to run or ignition not all the way off. 

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6 minutes ago, Katie said:

Thanks all really appreciate it. I don’t understand electrical stuff at all really (clearly) 

 

yes batteries seem to have been left flat for several weeks so I’m guessing they are just dead. 
 

alternator light on ignition goes off after engine started and key turned back. Only way I can get any power is to keep Key turned, but seems this is using starter battery to power 12v systems? 
 

I can get hold of a generator and have a charger on board used when hooked up to shoreline. So guessing I could just plug that into the generator and see if that manages to charge? 

 

Red bit: There is something here that makes no sense to me.

 

Typically, when you turn the key one position clockwise, the instruments and the warning lamps should come on. The next position if that position does not operate the starter is spring-loaded and turns the engine heater plugs on. The warning lamps may dim slightly. The next position clock wise, again spring-loaded, causes the starter to operate. When you let go of the key it springs back to the first clockwise position which keeps the instruments and warning lamps energised but the warning lamps should all go out with a bit of a rev. That is how you should run the engine.

 

If you physically turn the key off with the engine running (despite what some may claim, it won't do any harm) it is perfectly normal for the charge light to come back on and it tells me the alternator is producing some charge.

 

Blue bit: a bit unclear as to what you mean.

 

It seems that you may have not grasped that the  engine electrics (usually supplied by one battery) and the domestic 12v electrics are two separate circuits and only linked by a relay, diode or switch of some sort on single alternator boats. Now you talk about the only way of getting some power and I can't be sure if you are talking about power  for the engine electrics or domestic electrics. Now I suspect you mean the domestic systems and if so that tells me that you almost certainly have a simple split charge relay that, in your case, just joins the engine and domestic batteries together for charging when the ignition is on. So by having the ignition on the engine battery will supply the domestic power until that battery is flattened.

 

It sounds as if the alternator is chargng and points to the domestic batteries.

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4 minutes ago, Tracy D'arth said:

Why are you turning the "key" off after you have started the engine? It will stop the batteries from charging!!!!

Would you turn the ignition off on a car after starting and expect it to work?

 

Is there another boater near who could show you how to run your engine and charge the batteries?

 

Er, I am not sure if that is true. It depends upon what type of charge splitter the OP has. A diode, VSR or correctly positioned 1,2,both, off switch would all still allow the batteries to charge. Once energised the alternator should stay energised with the ignition off in most cases.

 

In this case I think it is an ordinary split charge relay and even then the output of the field diodes should keep the relay in the charge position, although those diodes would also try to feed the instruments etc. via the charge light and illuminate that.

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Are you sure that the batteries aren't still isolated? Even discharged and beyond help they normally produce bright lights for an hour or so with minimal input from the alternator. 

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Whenever I buy a boat I dont even look at the batteries other than to find out how many there are. I lways take a new set with me and connect on purchase. Dony waste your time with batteries you have no idea of the provenance of. Batteries are consumables like diesel. Fit a new set and try your best to look after them.

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This tells me again that some enterprising person could earn some money offering paid 1-2-1 'getting to know your new boat' sessions.  This exists for teaching newbies how to steer a boat safely but I only know of the RCR courses for learning how your boat works, but I don't think they offer that 1-2-1 on the person's boat.

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1 hour ago, mrsmelly said:

Whenever I buy a boat I dont even look at the batteries other than to find out how many there are. I lways take a new set with me and connect on purchase. Dony waste your time with batteries you have no idea of the provenance of. Batteries are consumables like diesel. Fit a new set and try your best to look after them.

That's fine for you. You know what you are doing. But Katie says she knows nothing of electrics, and her replies so far suggest she doesn't really understand what sort of charging system she has and how it works. Just replacing the (probably) dead batteries with a new set could very quickly result in a second set of dead batteries.

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Yeah would be good. I’ve done a helmsman course so happy handling her just all the electrical system stuff that I don’t understand yet. I suppose limitations to such courses would be the fact that every boat is set up differently as so many are DIY bodges 

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1 minute ago, doratheexplorer said:

Where are you Katie?  Maybe a forum member could pop over and look things over with you in exchange for tea and biscuits?

I’m on GU at Stoke Hammond currently.  Luckily I’m not fully living on it just yet But want to get my head around all this stuff before I need to be at end of the month. I know with batteries it’s important to charge them ASAP to limit long term damage so just want to check I’m even going about this the right way.

 

Thanks for all suggestions and replies folks. I shall do more investigation when I’m back on board tonight 

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4 minutes ago, Tony Brooks said:

I offered to visit with 30 miles of home but Stoke Hammond is a bit far.

 

 

And, yet again you prove what a very nice man you are.

I'm sure Katie will be grateful of your help.

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4 minutes ago, Alan de Enfield said:

 

And, yet again you prove what a very nice man you are.

I'm sure Katie will be grateful of your help.

 

Can't be, did you not read, I am a racist.

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I shall be going Stoke Hammond way, by next week, if a pair of eyes on the ground will be of help. (with meters, and spanners)

 

Bod.

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