new to boating, getting new leisure batts due to power problems?

[Kyle]

Hi!

 

We're new to boating and are on a boat with 4 leisure batteres (Xplorer 120Ah).

 

Very annoying power issues: the batteries don't seem to hold charge well at all, but it doesn't seem to be a busted cell (paid a guy to come around and tell us that much, but unfortunately not much more). We can charge to well above 12V and leave overnight with little drain, but as soon as the batteries are in use, or god forbid the inverter is on, they drain like there is no tomorrow. Also using certain items, like the 12V fridge, results in lights dimming, fllushing the loo results in radio resetting, etc) Is this all due to weak batteries? The problems do seem to be less when they are charged more.

 

Our solar arrives tomorrow, which will be a god send (we are continuous cruisers). At this stage we are considering taking the hit and just getting 4 new batteries. It is a real bother to run this loud old lister for hours to charge them up, disconnect them and wait for them to drain so I can test them each in turn. The thing is they were expensive batteries, and some of them might be fine.

 

If I buy some more batteries, is there a place I can test and sell the old ones? Do I even need 4 of them? If I could test them prior to buying new ones, wouldn't it be best to replace all of them at the same time anyway? Is there a big chain in London (aside from Halfords) where I can just rock up and get a good deal on leisure batteries?

 

Any help or advice would be much appreciated!!

 

 

[Arthur Brown]

First get the solar installed properly! Many battery problems vanish when they are properly charged. Get some kind of meter to tell you the state of your batterys' charge. Maybe get a current meter to check the current flowing in and out of the battery. Depending on the inverter and what it's driving then yes it will flatten a good battery in quick time.

[bottle]

Welcome

 

Three possibilities.

 

The batteries are 'broke',

 

You are using to much power,

 

You are not charging them enough

 

or

 

a combination of all three.

solar may help but could just mask the problem

[system 4-50]

How old are the batts?

[Detling]

It does sound as though they are not being charged enough. The solar will be a great help at this time of the year and if you have enough may well eliminate the need for charging any other way. You need at least 300 watts of solar to run a fridge water pumps and 2-3 hours of telly etc a day, laptops and phone/tablet charging comes extra, and anything serious via the inverter (hair dryer etc) will not be covered by 300 watts. In winter you would need 4 times that in solar panels. You need a meter to give you an indication of the state of charge of the batteries and you also need to do a power audit to find out how much power you use and how much individual devices take. An ammeter is very useful I find a clamp type best but make sure it does DC as well as AC current.. As an example via my inverter I know my microwave takes 130 amps, the toaster takes 70 amps and the wife's hair dryer 150 amps, these items are usually only on for a few minutes but those amphour figures do add up. Eg a round of toast 4 mins at 70 amps works out as 5 amp hours

[Arthur Brown]

You say you are new to boating so likely the history of the batteries is unknown to you. How old are they? As batteries age they lose capacity and high current discharge ability. Get the batteries to fully charged then see how much power consumption they will support before they are flat. I suspect that their rated 4 x 120 AH has reduced naturally to much less Maybe as little as 100AH the lot or less. Keeping them charged by solar will help a little but unless you have recent receipts assume that the batteries are OLD and fading away.

 

2 years is a fair life 3 -5 is very good and anything more indicates that you have taken significant care of them for all their life. Solar may help battery life.

[MtB]

Welcome to the base of a really long, steep learning curve.

 

Start off by doing a power audit. (Use the search facility.)

 

Then consider how you know you are currently returning this amount of energy to the batteries, plus an allowance for less than 100% efficiency.

 

Then post again with your figures for critical analysis!

Edited May 27, 2015 by Mike the Boilerman

[Alan de Enfield]

Hi!

...................We can charge to well above 12V and leave overnight with little drain, .....................

 

 

 

 

 

A 12v battery is NOT just 12v - at 12.1v it is only 50% charged.

 

As a starting point you really need to get somewhere where you can get your batteries fully charged, either on a 'mains hook-up' or run the engine for 8 hours +.

 

An 'intelligent' battery charger (including an alternator) will charge a partly depleted battery at maybe 13v gradually increasing up to 14.4 volts, at the same time the current (amps) charging rate will start 'high' and gradually get lower as the battery becomes charged. (this is why it takes much longer than you may expect to charge a battery - a 70 amp alternator will not charge your battery at 70 amps for very long - maybe just minutes - it will then gradually fall to 2 or 3 amps which is when your meter should show 14.4 volts)

 

A fully charged battery should show 12.8 volts.

 

A fully charged battery does not mean that you have the 120 ah available (or, in your case 4 x 120ah) as, as batteries age and get used the ah rating falls - it could be down to say 60ah in which case running a fridge and heavy use of an inverter are soon going to flatten them .

 

You really do need to do a power audit of your usage and work out how you are going to replace 110%-120% of that figure.

Edited May 28, 2015 by Alan de Enfield

[Tony Brooks]

Explanation and worked examples of the power audit and some rough charging calculations on my website. The ones in the maintenance notes are probably bets but read the electrical notes as well.

[bigcol]

My sympathys, just getting my head round our batterys, thanks to the joint effort of forum members.

 

Col

[Kyle]

Wow! Thanks for all of the wonderful replies guys! Boaters are so helpful. We got our solar today so the priority is getting that set up. To answer some of your questions, we have no idea how old the batteries are. I've spoken to the manufacturer and tried to get the info from the old owner but still waiting. The boat was moored for a few years before us, so I'm guessing the batteries took something of a hit from that. Having said that, she has a pro-charge ultra setup, which apparently protects them well. I'm currently running the engine at full rev and the power issues (radio turning off when loo is flushed, ect, have disappeared, so I'm glad we are definitely looking at power ((and not wiring issues). The guy who took a look said he suspected the alternator wasn't big enough for charging 4 leisures, so I think (hope) this is primarily a charging issue. The solar might help. In any case new batteries might be nice, are there any real problems with swapping them out for 4 80AH batteries? We don't have a TV and only charge laptops occasionally. The water heater runs from the inverter though.

 

I really do want to do a full diagnostic on these batts, but charging them up fully (without shore power) is time consuming and, frankly, loud. Do you reckon I can charge them up gradually with engine and solar, and when they read 12.6V I can disconnect and test individually?

 

Arthur, do you mean to say that the four batteries combined might well be giving less than 100AH now?!

[Dave Clinton]

He's guessing (intelligently but still guessing) as are you. It sounds like your expert was anything but or he would have answered all these questions without guessing.

 

The thing I wanted to pick up on your post was running the engine at full rev. This won't do anyone any good. Not you, not your batteries, not your neighbours. Borrow a clamp ammeter or buy one from Maplin and run your engine from idle slowing increasing the revs until the charging current doesn't change. It won't be the rating of your alternator but you'll be surprised how slow your engine is going when it reaches this. There's no point in going any higher.

 

Solar will help a lot over the next few months. Leave off buying new batteries until you've settled into using the solar which in the summer should give your batteries a good charge. Budget for buying batteries around equinox.

 

Once you are charging all day with the solar you will be able to tell first thing in the morning whether your batteries are shagged or not.

 

Tayna and Battery Megastore are the current faves for batteries, both mail order but as I say, don't rush into that.

 

Your water heater sounds like the killer, best to run that only when the engine is running or mid afternoon if the solar is dying down. Spend a bit more and get a controller with a meter and that will save you a bit on metering.

Edited May 28, 2015 by Dave Clinton

[Alan de Enfield]

Making some assumptions ;

 

You have 4 x 120 amp batteries that are 'half' goosed - you therefore have 240 ah to 'play with'.

 

Batteries are only rated at so many charges / discharges and the deeper the discharge the shorter the battery life - Ideally you should not take batteries below 50%, so you now have only 120 ah to play with.

 

If you have a 3kw immersion (water) heater that will use approximately 300 amps so your batteries will last abut 20 minutes.

If you have a 1kw immersion (water) heater that will use approximately 100 amps so your batteries will last abut 70 minutes

 

You should not be using batteries to heat water - electrical water heaters should only be used on a mains hook-up.

 

Even brand new batteries will soon be knackered using an immersion heater unless you have a very good re-charging regime, generator etc.

[Kyle]

Hah, as soon as I read your post about revving the engine, I jumped up to put her in neutral. More bad advice led us to doing that. The guy who was here did "rewire" the alternator so that the ignition light goes off when the alternator is powering the batteries... would the point when that light goes off (usually first gear) be the point to maintain for charging? The water heater is gas powered, but for some reason (probably just to spark but maybe more) it needs the inverter on. Would you recommend changing boilers?

 

Solar: We have a new MPPT controller with a meter too so got that covered.

 

Quick question regarding solar installation... the manual indicates putting a fuse between battery and controller, is this necessary with just 250W panel? I actually do have a fuse that I think I can use here, it was the one being used previously to protect that starter battery from the shore power (via the pro charge ultra), but it is now connected to nothing. Could I put that between the leisure bank and the controller? I am attaching pic of the fuse if it helps...

 

pic: https://drive.google.com/file/d/0B-eqQxcnWMK6M0VFaWk4RGZtNHNYNFJVM3ZjNllSZHNPZ2pN/view?usp=sharing

[bottle]

Making some assumptions ;

 

You have 4 x 120 amp batteries that are 'half' goosed - you therefore have 240 ah to 'play with'.

 

Batteries are only rated at so many charges / discharges and the deeper the discharge the shorter the battery life - Ideally you should not take batteries below 50%, so you now have only 120 ah to play with.

 

If you have a 3kw immersion (water) heater that will use be, approximately, 300 amp load so your batteries will last abut 20 minutes.

If you have a 1kw immersion (water) heater that will use be, approximately, 100 amp load so your batteries will last abut 70 minutes

 

You should not be using batteries to heat water - electrical water heaters should only be used on a mains hook-up.

 

Even brand new batteries will soon be knackered using an immersion heater unless you have a very good re-charging regime, generator etc.

 

Apologies Alan but we do not want to confuse more that the OP is already

[Alan de Enfield]

 

Apologies Alan but we do not want to confuse more that the OP is already

 

No problem.

 

I am not sure if the OP has a boat ( ..... would the point when that light goes off - usually first gear -.....) or if it is a 'wind-up'.

 

If the OP does have a boat with these problems I think that he needs to employ a skilled boat electrician - there seems to be too much going on for internet diagnosis.

[Phil Ambrose]

Not just any fuse will do, the idea is that the fuse protects the wiring, with 250w solar the output of your panel is around 20amps so your fuse needs to be big enough to cope with the max expected current otherwise the fuse will just blow , minimum 25a fuse should do it.

Phil

[bottle]

Hah, as soon as I read your post about revving the engine, I jumped up to put her in neutral. More bad advice led us to doing that. The guy who was here did "rewire" the alternator so that the ignition light goes off when the alternator is powering the batteries... would the point when that light goes off (usually first gear) be the point to maintain for charging? The water heater is gas powered, but for some reason (probably just to spark but maybe more) it needs the inverter on. Would you recommend changing boilers?

 

Solar: We have a new MPPT controller with a meter too so got that covered.

 

Quick question regarding solar installation... the manual indicates putting a fuse between battery and controller, is this necessary with just 250W panel? I actually do have a fuse that I think I can use here, it was the one being used previously to protect that starter battery from the shore power (via the pro charge ultra), but it is now connected to nothing. Could I put that between the leisure bank and the controller? I am attaching pic of the fuse if it helps...

 

pic: https://drive.google.com/file/d/0B-eqQxcnWMK6M0VFaWk4RGZtNHNYNFJVM3ZjNllSZHNPZ2pN/view?usp=sharing

 

I'm hoping that this is a typo and that the engine was not in gear with the prop turning, if it was and you are C&RT waters, you are contravening your licence terms

 

No, that is when the alternator starts charging, your engine needs to run at sufficient rpm to enable the alternator to run at over 1,000 rpm

The only way to know the most efficient speed is with an ammeter in circuit or a clip on one that can read dc.amps

 

Yes it is necessary, otherwise it would not be in the manual, it needs to be of sufficient size (amps) to protect the connecting cables and they (the cables) need to be of sufficient size (mm²) to not cause volt drop and carry the maximum current (amps) that your panels can supply

 

No problem.

 

I am not sure if the OP has a boat ( ..... would the point when that light goes off - usually first gear -.....) or if it is a 'wind-up'.

 

If the OP does have a boat with these problems I think that he needs to employ a skilled boat electrician - there seems to be too much going on for internet diagnosis.

 

I was composing whilst you posted but I am beginning to come to the same conclusion.

[Tony Brooks]

At the present I do not think its a wind up. I think the OP has very little mechanical/electrical aptitude or knowledge and even less knowledge about boats. I think he may well have bought a dog and has been given some very poor advice - especially by the so called expert. Look at the location, probably been suckered into the cheap housing market.

I suspect the water heater may be the large balance flue Morco instant water heater that requires mains ignition. If not please identify the heater or send a photo.

To the OP (Kyle)

The fact the charge warning lamp was not going out when the engine was running tells us it is very unlikely that the batteries were being charged.

The fact that the boat had been left standing for some years tells us the batteries are probably sulphated to hell and even if they do not have any internal short circuits are likely to have hardly any capacity now.

The fact you talk about full revs and first gear suggest that you have not done anything like enough homework to enable you to understand what is going on.

Sorry to be blunt blunt you MUST do a power audit. This will tell you how much electricity you need to store (my calculations allow for not discharging below 50%) You then need to do the charging calculations to see how long you need to run your engine for to all but fully charge your batteries. This will be a long time, several or many hours.

You also need to take heed of the advice about how to maximise the charge for minimum engine speed.

Only then even consider new batteries otherwise you could wreck them in weeks. Remember Solar is only an additional charging source and is no magic solution. You need to monitor the batteries state of charge so you only run the engine as much as required to maximise battery life. You may have to rethink your electrical use, especially any mains via inverter powered stuff.

 

Edited to correct spellings - must have used OE instead of Chrome so no red lines!

Edited May 29, 2015 by Tony Brooks

[Arthur Brown]

Wow! Thanks for all of the wonderful replies guys! Boaters are so helpful. We got our solar today so the priority is getting that set up. To answer some of your questions, we have no idea how old the batteries are. I've spoken to the manufacturer and tried to get the info from the old owner but still waiting. The boat was moored for a few years before us, so I'm guessing the batteries took something of a hit from that. Having said that, she has a pro-charge ultra setup, which apparently protects them well. I'm currently running the engine at full rev and the power issues (radio turning off when loo is flushed, ect, have disappeared, so I'm glad we are definitely looking at power ((and not wiring issues). The guy who took a look said he suspected the alternator wasn't big enough for charging 4 leisures, so I think (hope) this is primarily a charging issue. The solar might help. In any case new batteries might be nice, are there any real problems with swapping them out for 4 80AH batteries? We don't have a TV and only charge laptops occasionally. The water heater runs from the inverter though.

 

I really do want to do a full diagnostic on these batts, but charging them up fully (without shore power) is time consuming and, frankly, loud. Do you reckon I can charge them up gradually with engine and solar, and when they read 12.6V I can disconnect and test individually?

 

Arthur, do you mean to say that the four batteries combined might well be giving less than 100AH now?!

 

Yes it's likely that a set of house batteries of two years old or six months left standing will have dramatically less capacity than the label says.

 

Give up battery games for today! Get the solar installed correctly ASAP. Then work out a full circuit diagram of your boat Every wire, Every machine and every box you don't identify.

Get yourself a DC ammeter and a separate voltmeter. Look where current flows with the ammeter then track the battery voltage over a few discharge cycles.

Knowing the current supported over time for a battery cycle will let you estimate the battery capacity.

 

Note that (IMO) electric water heating by inverter is probably the most expensive way of making hot water and it will be flattening the batteries rapidly.

[Dave Clinton]

Hah, as soon as I read your post about revving the engine, I jumped up to put her in neutral. More bad advice led us to doing that. The guy who was here did "rewire" the alternator so that the ignition light goes off when the alternator is powering the batteries... would the point when that light goes off (usually first gear) be the point to maintain for charging? The water heater is gas powered, but for some reason (probably just to spark but maybe more) it needs the inverter on. Would you recommend changing boilers?

 

Solar: We have a new MPPT controller with a meter too so got that covered.

 

Quick question regarding solar installation... the manual indicates putting a fuse between battery and controller, is this necessary with just 250W panel? I actually do have a fuse that I think I can use here, it was the one being used previously to protect that starter battery from the shore power (via the pro charge ultra), but it is now connected to nothing. Could I put that between the leisure bank and the controller? I am attaching pic of the fuse if it helps...

 

pic: https://drive.google.com/file/d/0B-eqQxcnWMK6M0VFaWk4RGZtNHNYNFJVM3ZjNllSZHNPZ2pN/view?usp=sharing

the revving up until the alternator light goes out only has to be done at the start, you can lower the revs after that but really need an ammeter to know exactly where. a cheap voltmeter (or indeed your solar controller) will also show you. you want the lowest speed where the voltage stays constant.

 

without looking fuse sounds good, same sort of application

 

which water heater? I wouldn't normally expect a heater that needed 230v. or do you mean immersion heater?

[Phil Ambrose]

Kyle, so now you know what you have to do, read and absorb all of the above posts and try to get your head round all the advice you have been given, then try to do as advised. Living on a boat is a very steep learning curve, we've all been there so just keep coming back and ask about anything you are unsure of.

Good luck,

Phil