Battery monitoers etc.

[AlanH]

I think that many probably consider a battery and it's warranty to be similar to a domestic appliance or an engine i.e. a washing machine has a two year warranty but with proper use and care could last 10 years or more. Unfortunately a battery with a two year warranty will probably last just that or even less if cycled daily with a realistic charging regime.

As I said, my batteries are at least four years old and seem to be working well enough. Those of you who want to, can get as anal as you like about monitoring/managing etc. but I see no evidence that doing so prolongs battery life beyond four years. If mine will last for five years given our usuage then I am happy. I'm not going to spend hundreds of pounds just to find out what state they may be in. I'll happily replace the batteries every five years as those of you who monitor/manage will have to do anyway.

I can see that if you live aboard there might be some advantage.

Edited March 10, 2010 by AlanH

[mayalld]

Impossible.

 

Rough order of magnitude?

[alan_fincher]

I don't really understand why there is so much talk on this forum about battery charging/monitoring systems. Our system is about as simple as you can get:

 

Single 55amp alternator

Split charge relay.

One 50Ah starter battery.

Two Leisure batteries (Not sure of the size).

12v fridge only used when cruising for more than a couple of days.

 

 

We use the boat most weekends although we don't tend to stay on board and watch TV all evening. We have no shoreline.

The batteries are at least four years old and I can't see any sign of their performance deteriorating at all.

I can understand those liveaboards who want to use microwaves/washing machines etc on an inverter needing morre charging capacity etc but why would I need expensive devices to monitor our system?

 

You don't need one - you have proved it, if you consider a 4 year plus life of your domestic batteries as acceptable, (as I would).

 

We don't need one, particularly as we have a gas rather than electric fridge, and cruise a lot, never stopping very long.

 

Someone with far more electrical equipment, or whose pattern is skewed far to "moored" than "moving" is far more likely to make them useful, I'm guessing.

 

I'd have one, and use it, if someone gave me one.

 

Or I can save the money, knowing it will virtually pay for the next replacement of our domestic battery bank.

 

I do like an ammeter, however, crude though, to get the warm feel that charging is actually happening, and roughly how fast. A lot cheaper than a SG or any other battery monitor, though.

 

Horses for courses, I believe.

 

Similar argument whether the expenditure on an external alternator controller is useful. I think they probably would make my batteries charge faster in some cases, but equally I don't need that, and could buy a lot of batteries with money saved.

 

My first narrow boat had just a dynamo, and a single battery for starting and domestics - we got on fine, but I'm not about to tell anyone they can't have their microwave or hair drier!

[AlanH]

You don't need one - you have proved it, if you consider a 4 year plus life of your domestic batteries as acceptable, (as I would).

 

We don't need one, particularly as we have a gas rather than electric fridge, and cruise a lot, never stopping very long.

 

Someone with far more electrical equipment, or whose pattern is skewed far to "moored" than "moving" is far more likely to make them useful, I'm guessing.

 

I'd have one, and use it, if someone gave me one.

 

Or I can save the money, knowing it will virtually pay for the next replacement of our domestic battery bank.

 

I do like an ammeter, however, crude though, to get the warm feel that charging is actually happening, and roughly how fast. A lot cheaper than a SG or any other battery monitor, though.

 

Horses for courses, I believe.

 

Similar argument whether the expenditure on an external alternator controller is useful. I think they probably would make my batteries charge faster in some cases, but equally I don't need that, and could buy a lot of batteries with money saved.

 

My first narrow boat had just a dynamo, and a single battery for starting and domestics - we got on fine, but I'm not about to tell anyone they can't have their microwave or hair drier!

Quite, and a battery management system won't stop batteries needing replacement ayway so you may get an extra few months or a year out of them that is all. Not worth the money given our useage.

I couldn't live aboard without greatly increasing my power consumption and then I might find such devices useful.

[John Orentas]

I don't really understand why there is so much talk on this forum about battery charging/monitoring systems. Our system is about as simple as you can get:

 

 

Fully agree with all of that, in many walks of life it is possible for some people to invent a problem that doesn't exist and then attain 'Hero status' by inventing a cure, and dare we say making a few bob at the same time..

Edited March 10, 2010 by John Orentas

[nb Innisfree]

Rough order of magnitude?

 

Ok just for you, our last lot lasted an extra 9 months or so, can't be really certain, approx an extra 30%?

[Roger Gunkel]

I don't really understand why there is so much talk on this forum about battery charging/monitoring systems. Our system is about as simple as you can get:

 

Single 55amp alternator

Split charge relay.

One 50Ah starter battery.

Two Leisure batteries (Not sure of the size).

12v fridge only used when cruising for more than a couple of days.

 

 

We use the boat most weekends although we don't tend to stay on board and watch TV all evening. We have no shoreline.

The batteries are at least four years old and I can't see any sign of their performance deteriorating at all.

I can understand those liveaboards who want to use microwaves/washing machines etc on an inverter needing morre charging capacity etc but why would I need expensive devices to monitor our system?

 

You say that you really don't understand why there is so much talk about charging monitoring etc!

 

I don't really understand the point of your original post as you clearly have absolutely no need for such talk or monitors, as you are unlikely to come into the area of charging/monitoring to 'need to know'.

 

The way that you are using your boat probably means that you are getting perhaps 50 days? use out of your boat over the year. You are probably cruising for many of those days putting charge in the batteries and, as you say, consuming little power and highly unlikely to ever flatten your batteries. By contrast, I am on my boat 365 days per year and running my business from it. I need to know at all times what charge I have in my batteries and how much power I am consuming, so I need to monitor the batteries and understand what is going on. It has little to do with prolonging the battery life, although not abusing them will help, but more about knowing that I always have enough power.

 

You have used the same batteries for 4 years and will be happy if they last five. I will take more from my batteries in 1 year than you will in 5, but I would be annoyed if they only lasted for 1. Monitoring and maintaining them will hopefully give me 2-3 years, helped by all the talk and discussion on this forum.

 

Roger

[mayalld]

Ok just for you, our last lot lasted an extra 9 months or so, can't be really certain, approx an extra 30%?

 

I always reckon on batteries lasting about 3-4 years before they start to get tired, and don't hold as much charge as I want them to.

 

I also reckon that much like depreciation on a new car, they lose a lot of capacity early in their lives, and that as they get older they lose less.

 

Let us assume that a battery loses 2% of its Present capacity every month.

 

In the first month it loses 2%, and falls to 98% of its original capacity. In the second month it loses 2% of 98% = 1.96%, and so on.

 

In the first 12 months it will lose 21% of its original capacity, leaving 79%, and after 2 years it will be down to about 61%, having lost a further 18%. In the following year, it will lose only 13%, taking it to 48%, and in the fouth year, will lose just 10%, down to 38%

[AlanH]

You say that you really don't understand why there is so much talk about charging monitoring etc!

 

I don't really understand the point of your original post as you clearly have absolutely no need for such talk or monitors, as you are unlikely to come into the area of charging/monitoring to 'need to know'.

 

The way that you are using your boat probably means that you are getting perhaps 50 days? use out of your boat over the year. You are probably cruising for many of those days putting charge in the batteries and, as you say, consuming little power and highly unlikely to ever flatten your batteries. By contrast, I am on my boat 365 days per year and running my business from it. I need to know at all times what charge I have in my batteries and how much power I am consuming, so I need to monitor the batteries and understand what is going on. It has little to do with prolonging the battery life, although not abusing them will help, but more about knowing that I always have enough power.

You have used the same batteries for 4 years and will be happy if they last five. I will take more from my batteries in 1 year than you will in 5, but I would be annoyed if they only lasted for 1. Monitoring and maintaining them will hopefully give me 2-3 years, helped by all the talk and discussion on this forum.

 

Roger

I can understand that but a lot of people who use their boat about a frequently as I do -probably about 70 days per year- have purchased these devices.

 

I always reckon on batteries lasting about 3-4 years before they start to get tired, and don't hold as much charge as I want them to.

 

I also reckon that much like depreciation on a new car, they lose a lot of capacity early in their lives, and that as they get older they lose less.

 

Let us assume that a battery loses 2% of its Present capacity every month.

 

In the first month it loses 2%, and falls to 98% of its original capacity. In the second month it loses 2% of 98% = 1.96%, and so on.

 

In the first 12 months it will lose 21% of its original capacity, leaving 79%, and after 2 years it will be down to about 61%, having lost a further 18%. In the following year, it will lose only 13%, taking it to 48%, and in the fouth year, will lose just 10%, down to 38%

Surely that depends on how much the battery is used. Why assume 2% pcm?

[WotEver]

I can understand that but a lot of people who use their boat about a frequently as I do -probably about 70 days per year- have purchased these devices.

 

There will always be people who...

 

1. Like gadgets

 

2. Like to know a little more about what's happening to the services on their boats.

 

or...

 

3. Like gadgets and want to know a little more about what's happening on their boats.

 

None of those three categories necessarily need battery charge monitoring but that's no reason why they shouldn't have it if they so choose.

 

Tony

[Roger Gunkel]

I can understand that but a lot of people who use their boat about a frequently as I do -probably about 70 days per year- have purchased these devices.

 

I totally agree with that Alan However I responded because your original post said "I don't really understand why there is so much talk on this forum about battery charging/monitoring systems". My point being that there are many people who do benefit from the talk and information, aswell as those that have no need of it.

 

Roger

Edited March 10, 2010 by Roger Gunkel

[AlanH]

I totally agree with that Alan However I responded because your original post said "I don't really understand why there is so much talk on this forum about battery charging/monitoring systems". My point being that there are many people who do benefit from the talk and information, aswell as those that have no need of it.

 

Roger

Fair enough - I should have excluded liveaboards.

[Roger Gunkel]

Fair enough - I should have excluded liveaboards.

 

It's only a forum Beer?

 

Roger

[mayalld]

Surely that depends on how much the battery is used. Why assume 2% pcm?

 

It is a rough guess based on my own usage of the boat.

 

Clearly usage patterns, will affect the absolute value of capacity decline, but the principle still stands.

 

Broadly speaking, having fairly rapidly dropped to the mid 70% range, once batteries reach 60% capacity the rate of decline will have slowed.

[blodger]

The trouble is that they WON'T go on forever at 50/60% capacity.

 

If they would, we would all fit our boats for double sized banks.

&

Broadly speaking, having fairly rapidly dropped to the mid 70% range, once batteries reach 60% capacity the rate of decline will have slowed.

 

I suppose some people stick with one bank and replace as soon as its obvious that they are not upto it anymore. I and it seems others have found that doubling the banks means you can get a bit more out of the old before dumping them.

 

It seems we are agreed that the rate of further decline diminishes with time.

 

I hate to see batteries that have life in them just dumped but accept folk have differing agendas, etc

[Guest]

I think people use sophisicated battery monitoring for conveninece. Just as you can dip your fuel tank with a broom handle, I imagine it is far more convenient to have a fuel gauge (though I don't have one.) My battery monitoring consists of a voltmeter, and not a very good one. I did have an ammeter but don't need it anymore. I am a semi livaboard and get several years out of my batteries, which I tend to by secondhand ex standby. Failing that I would buy truck starter batteries,cos I am not convinced by leisure jobbies. No shorepower; we live off the engine, and sometimes a genny with Stering charger.

[smileypete]

&

Broadly speaking, having fairly rapidly dropped to the mid 70% range, once batteries reach 60% capacity the rate of decline will have slowed.

 

I suppose some people stick with one bank and replace as soon as its obvious that they are not upto it anymore. I and it seems others have found that doubling the banks means you can get a bit more out of the old before dumping them.

 

It seems we are agreed that the rate of further decline diminishes with time.

 

I hate to see batteries that have life in them just dumped but accept folk have differing agendas, etc

If I was living aboard without a shoreline, give the choice I'd have space for TWO banks, that could be used independently and charged independently or together.

 

That would give a lot more options for getting batteries fully charged or fully desulphating them.

 

OK using a smaller bank than possible loses a bit of efficiency through 'Peukert' effects, but you lose efficiency AND capacity in spades if batts get sulphated.

 

I wouldn't buy two banks up front though, just add the second one when the first gets a bit tired, maybe from someone who's given up on theirs

 

cheers,

Pete.