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Batteries again


Top cat

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Sorry, it's  batteries  again.
Four years ago we fitted 4x Multicell sfl110 , 110Ah vrla maintenance  free batteries. Now after 350 mainly shallow cycles they are well down on capacity such that the voltage collapsed at about 70Ah discharge . Normally we discharge them to -40Ah and they handle that just fine  with the voltage stayng above 12.8most of the time.  They also handle very occaisional brief loads up to 90A and recover to almost the same voltage quickly. 
I noticed that there is evidence of electrolyte leakage from the relief valve,  does that indicate  overcharging?. 
We have 3 charge methods, alternator via an Adverc controller, solar panel via a victron controller and on rare occasions  a ctek mains charger. All of those are supposed to limit the voltage to 14.4V but my BMV monitor has recorded up to 14.5V but at low current.
The batteries are  never left discharged, normally we cruise for about 5 hrs a day and by the end they are up at 14.4V taking less than 4A.

They spend a lot of time on float charge at 13.8V from the solar panel soget a very shallow cycle each night, I havent included that in the 350 cycle count.
When I start the engine the battery  voltage goes straight to 14.4v no matter what the discharge, after the -70Ah event the initial current was only 37A from a 110A alternator.

After all that background some questions

Is 350 cycles a reasonable life from sealed batteries? Is it time or cycles that kill batteries 
What should I do to increase their life
Is an Adverc suitable for sealed batteries?
If I take the adverc out what do I do with the white wire coming from the field connection on the alternator?
Should I get conventional open cells next time? But access is difficult  and topping up might not get dome often enough or very accurately  ( thats why I went maintenance  free).
If I go for the fancy AGM or gell batteries will i have to replace my chargers and controllers? If so with what?
Any ideas on what could be causing the electrolyte loss?

Thanks

Terry

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Just now, Top cat said:

I'm not  aware of any option to adjust the adverc, its about 11 years old. The manual such as it is says nothing about adjustment 

Oh , ok. My sterling alternator controller has different settings for different battery types. 

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Standard cheapo leisure batteries usually have a quoted spec of 300 cycles, that is if they have any spec at all. You have done shallow cycles so could maybe  expect more than 300. I suspect 14.4volts might be a bit low but this will depend on how much you discharge them before your 5 hour cruise. A few longer cruises of maybe 8 hours might have helped. There are loads of threads here about battery types, charging voltage, charging regimes and equalisation, but unless this sort of stuff turns you on I would just buy some new batteries, you are doing ok.

.............Dave

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Can I ask  a similar question please. I am like the original poster, with four 110ah domestic batteries about to be replaced, they have been OK, but after a few years they have got tired. Because of where the batteries are I need non maintenance ones like AGM. I have a Victron charging system so it can be adjusted to match the batteries fitted.

The battery supplier is offering me standard leisure batteries at about £90.00 pounds each - with 300-350 cycles quoted. But he is also offering higher spec AGMs that are quoted as approx 900 cycles at £230 each.

Most of my cruising is a few weeks each year in the summer months so I am not expecting heavy battery use. but I have an eberspacher hydronic d5wsc running a few radiators, which I would like to be able to use for evening cabin heating for a few short winter cruises. So I think I have a couple of questions.

Is it feasible to run the eberspacher on the battery bank for a few hours, what is the typical load?

And is it worth paying the extra money for higher spec batteries that will hopefully last  a lot longer, and cope with some bigger discharges, or just get the bog standard ones and be prepared to replace them a bit sooner?

I suspect the answer will be go for the basic ones, but it would be good to hear if there are any dissenting voices, and advantages to the higher spec ones.

Thanks

 

 

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You will wreck ANY lead acid battery if you do not look after them well enough so before we can judge how well you look after them we need to know how many years they lasted. The resting voltage just before you go to bed at night, and exactly what you mean by a Victron charging system. I fear the latter could be a battery destroying meter.

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Thanks Tony, your first comment reinforces my intuition that any battery (even expensive batteries) can be damaged by poor treatment or inexperience, so buying expensive batteries can be risky, and I will probably be best buying the reasonable but cheap ones. But I just want to check if there are advantages to the expensive option.

It's an eight year old boat, currently with the original batteries, but they now seem to be way down on capacity. They are also open cell units in a position where they can't be topped up without removing them, so I doubt how well they have been maintained in the past.

The boat has been cruised for about 500 engine hours total (i.e. not much), but used quite often as a liveaboard by it's first owner, and then by us in the three years we have owned it. So parked alongside for years with the batteries connected to a Victron Phoenix Multiplus sytem. 

But having retired I now want to go cruising for a couple of months every summer, and I am looking to replace the batteries before I go off in a few weeks. I used to be a naval submarine officer, working in  the old diesel-electric boats, but that was 30 years ago, so I have a pretty good feel for lead acid battery theory and practice, but little up to date knowledge specific to canal boat batteries and charging systems, so I am keen to learn what I can, but aware of the risk of damaging batteries during my learning curve.

I don't know the night time resting voltage after a typical days cruising, but sadly the current batteries appear to be so far gone that I am not sure that any measurements I make with them still fitted might be helpful. But having said that, I am aware that the current batteries have sat on float for years with very few discharge cycles beyond a few percent. I understand that can be bad for batteries, and is there a chance the present batteries can regain condition if I take them cruising and start to cycle them?

Simon

 

 

 

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5 minutes ago, Simon D said:

is there a chance the present batteries can regain condition if I take them cruising and start to cycle them?

At 8 years old it's doubtful but hey, you never know. 

As for your earlier question about whether it's worth paying for 'better' batteries, yes, but only if you are going to look after them optimally. Hence Tony B's comments. 

Tony

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9 minutes ago, Simon D said:

Thanks Tony, your first comment reinforces my intuition that any battery (even expensive batteries) can be damaged by poor treatment or inexperience, so buying expensive batteries can be risky, and I will probably be best buying the reasonable but cheap ones. But I just want to check if there are advantages to the expensive option.

It's an eight year old boat, currently with the original batteries, but they now seem to be way down on capacity. They are also open cell units in a position where they can't be topped up without removing them, so I doubt how well they have been maintained in the past.

The boat has been cruised for about 500 engine hours total (i.e. not much), but used quite often as a liveaboard by it's first owner, and then by us in the three years we have owned it. So parked alongside for years with the batteries connected to a Victron Phoenix Multiplus sytem. 

But having retired I now want to go cruising for a couple of months every summer, and I am looking to replace the batteries before I go off in a few weeks. I used to be a naval submarine officer, working in  the old diesel-electric boats, but that was 30 years ago, so I have a pretty good feel for lead acid battery theory and practice, but little up to date knowledge specific to canal boat batteries and charging systems, so I am keen to learn what I can, but aware of the risk of damaging batteries during my learning curve.

I don't know the night time resting voltage after a typical days cruising, but sadly the current batteries appear to be so far gone that I am not sure that any measurements I make with them still fitted might be helpful. But having said that, I am aware that the current batteries have sat on float for years with very few discharge cycles beyond a few percent. I understand that can be bad for batteries, and is there a chance the present batteries can regain condition if I take them cruising and start to cycle them?

Simon

 

 

 

I agree with WotEver on both counts. You did very well to get 8 years out of the batteries so the odds are in your favour if you buy an expensive set.

With modern lead calcium batteries they do not really gas much at all at normal charging voltages until a cell shorts internally so they rarely need topping up unless you use something that charges at more than about 14.6 volts or do equalisation charges. My guess is that yours are not only sulphated but have now developed a short or two.

Its good your Victron is just a charger inverter. I feared it might have been an amp hour counter

The question about the resting voltage just as you go to bed would give an indication of how well the batteries were charged at that time and thus how deeply you were cycling them when off shorepower. I would suggest that you make a habit of noting that reading and trying to keep it above about 12.4V. Eventually (probably after many years in your case) you will find it dropping. If you can explain that by a short cruising day or using more electricity than normal that evening then its not a worry but when you cant explain it it is often a early sign of sulphation or a shorting cell.

If the ends of your batteries are bowing out its a sign of excess suphation and its time to change them.

 

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Thanks for the replies - very helpful.

Incidentally Tony, the knowledge of canal boat electrics I do have is based on a set of your Reading College teaching notes I found on the internet back in 2004. I found them to be superbly helpful. Thank you.

If I wanted to take this learning further are there any more recent publications, which take on new developments like the Victron, or are there any courses available? Perhaps a bit more learning here could be a good investment of my time and money?

Best wishes

Simon

 

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That Victron booklet is perfect, thanks. It's not that I don't know about batteries. But the last ones I worked with were 440V DC, 7420Ah, and things have changed a bit since then.

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