Deep Cycle Domestic Battery..

[vyv_cox]

There is nothing so certain than that there are no correct answers when it comes to battery questions. Whatever is suggested will be contradicted by somebody else. Any positive experience will be trumped by somebody else's negative. The nerdy experts never agree amongst themselves when it comes to the detail and the slightly knowledgeable are insulted by the equally slightly knowledgeable.

Buy whatever you like, at the lowest price you can. It cannot be the wrong decision. Or the right one.

 

[geem]

What makes a decent battery? I believe there is a lot of hype about batteries. They are very simple devices. Looked after properly cheap batteries will last a long time. A proper charging system is essential. Abuse batteries and they will fail. I agree that buying quality batteries and not looking after them is a waste of good money. Try claiming on a warranty on an expensive battery. You are unlikely to get much success. The manufacturer normally claims abusive treatment.
If you have a good charging system you won't need expensive batteries

 

[pvb]

I have been considering going for Gel or AGM, I understood them to be more robust if left standing partially charged and being really deep cycled...

When I bought the boat she had 3 batteries. 2 Lead acid that appeared newer than a Gel Cel. The 2 lead acid batteries where knackered and the Gel still going strong, I was so impressed to me Gel was the way forward.

I removed the 3rd battery (not required) and on the advise of the local boat electrician this year I had been using a new 100amp starter battery (bought for boat) for the domestic and the Gelcel on the engine.

The 100amp starter battery is now in the Landy, as its battery died.

I believe my alternator is only little so cannot handle to big a battery say max 85 ish amp hour, the electrician scowled at the alternator trying to charge the big battery, never mind 3 batteries.

If you leave any battery in a discharged state for long, it will deteriorate.

If you discharge any battery below say 50%, it will seriously reduce its life.

Theoretically, you shouldn't mix gel and ordinary batteries, but if you don't have a "smart" regulator on your alternator you'll probably be OK.

Regardless of your electrician's facial expressions, your alternator will almost certainly cope with more batteries. Indeed, having more batteries would improve your charging efficiency, as a bigger battery bank can more easily absorb the potential output of the alternator.

If you have more batteries then, for a given usage, each battery will suffer a lower depth of discharge, and therefore their life expectancy will increase.

Your best bet is to get 2 or 3 cheap wet lead acid batteries and wire them in parallel as one domestic bank. Whether you buy new or used is your choice, but the bigger the bank, the fewer problems you'll have.

 

[onesea]

I am impressed there is no one shouting the odds, there is little positive advise one way or another agreeing or disagreeing...

As I understand the general consensus (if there is one) is:

We should spend about £400 on solar panels and battery management equipment and then to run the engine for a whilst to look after the batteries (which then might last 5-6 years?)...

If not we can expect our batteries to last 4 years...

As I have no plan on making the boat more complicated and heavier with more equipment to go wrong battery management is out along with extra batteries. Although I will submit to a slightly larger battery, as batteries do not like to deep cycling that seems sensible. So which would you choose?

Lead Acid Leisure 85 ah £55 500 cycles,
Lead acid Leisure 120 ah £115 500 cycles,
AGM (Like Gel) Leisure 85Ah £115 800 cycles,
AGM (Like Gel) Leisure 120Ah £145 800 cycles,

I can see why people go for banks of 85 amp batteries but I do not want the extra battery space is limited and she is wired for 1 domestic now not 2...

 

[pvb]

I am impressed there is no one shouting the odds, there is little positive advise one way or another agreeing or disagreeing...

As I understand the general consensus (if there is one) is:

We should spend about £400 on solar panels and battery management equipment and then to run the engine for a whilst to look after the batteries (which then might last 5-6 years?)...

If not we can expect our batteries to last 4 years...

As I have no plan on making the boat more complicated and heavier with more equipment to go wrong battery management is out along with extra batteries. Although I will submit to a slightly larger battery, as batteries do not like to deep cycling that seems sensible. So which would you choose?

Lead Acid Leisure 85 ah £55 500 cycles,
Lead acid Leisure 120 ah £115 500 cycles,
AGM (Like Gel) Leisure 85Ah £115 800 cycles,
AGM (Like Gel) Leisure 120Ah £145 800 cycles,

I can see why people go for banks of 85 amp batteries but I do not want the extra battery space is limited and she is wired for 1 domestic now not 2...

It does make you wonder why people ask for advice in the first place...

 

[geem]

I recently bought two new 20 watt solar panels on eBay for £20 each. Regulator was another £25. Total expense to look after your batteries would be £65.
Buy another £55 battery and you are in business. Total cost £120. Same price as your expensive battery option.
My pal runs a heater, autopilot, lights, instruments and fridge froma single 110 amphour domestic battery. Done several seasons with it. The difference is he has 80 watts of solar connected. It rarely gets discharged due to constant solar charge during the day.

 

[Pleiades]

Deep cycling delights.

My point is that even with some free charging capability, (wind/solar) if you deep cycle the "Leisure" multi purpose batteries they will never get back to anywhere near their original capacity and will be more ready to let you down when you need them. I would never consider runnning the engine to charge batteries and typically would run the engine just to clear harbour or weigh anchor. So after say three days at anchor in the winter with no sun and light wind, Leisure batteries do not deliver for me - after maybe a dozen deep discharge cycles -that is to say below 50% - they flop. The Haze beasties however are rated as good for 550 cycles below 50% capacity - that is what proper deep cycling batteries give you. They are rated at 270 100% Depth of Discharge cycles. Leisure batteries in no way compare. If you don't need that capactity or you are happy to run the engine to prevent deeep cycling or have better access to the big sky heater then of course save the money and buy "Leisure".

Robin
Pleiades of Birdham
MXWQ5

 

[Plevier]

I am impressed there is no one shouting the odds, there is little positive advise one way or another agreeing or disagreeing...

As I understand the general consensus (if there is one) is:

We should spend about £400 on solar panels and battery management equipment and then to run the engine for a whilst to look after the batteries (which then might last 5-6 years?)...

If not we can expect our batteries to last 4 years...

As I have no plan on making the boat more complicated and heavier with more equipment to go wrong battery management is out along with extra batteries. Although I will submit to a slightly larger battery, as batteries do not like to deep cycling that seems sensible. So which would you choose?

Lead Acid Leisure 85 ah £55 500 cycles,
Lead acid Leisure 120 ah £115 500 cycles,
AGM (Like Gel) Leisure 85Ah £115 800 cycles,
AGM (Like Gel) Leisure 120Ah £145 800 cycles,

I can see why people go for banks of 85 amp batteries but I do not want the extra battery space is limited and she is wired for 1 domestic now not 2...

I don't know if there is a consensus and I for one am not going to tell you what to do or buy.
I have simply told you some truths about batteries and your use regime, based on considerable experience with a major manufacturer.
Two more things.
Gel and AGM are very different in construction, behaviour and charging requirements.
Pay little attention to life claims of cheap leisure batteries and if you think the warranty is comforting, read the small print.

 

[onesea]

My useage on my Centaur is similar, I have a 100Amp hr leisure battery from the local caravan shop, £90 IIRC 4 years ago, it needs replacing though, I have left it undercharged too many times.

It may be a waste but £25 a year isn't much in the greater scheme of running a boat and I can't be arsed managing the battery to double the life for the sake of £25 a year.

I know exactly what you mean, although that's why the battery gets such a hard life... I would rather be sailing, I would not run the engine to give the battery a charge unless I had to. I am just aware that its an option if things ain't going to plan.

This may well be the best idea.
You are treating your battery so badly you are unlikely to get the benefit of a high quality one.
Spoil a cheap one instead.

That would always of been my thinking, if it was not for that older gel style one that has continued to supply what is necessary when 2 others have failed.

It does make you wonder why people ask for advice in the first place...

Another constructive comment, thank you, I could question why some people post on the forums... I could point out how often I have said that I want to maintain my existing charging system. Quantity of batteries and stay without solar charging, yet I can think of threads where I have done the same.

I recently bought two new 20 watt solar panels on eBay for £20 each. Regulator was another £25. Total expense to look after your batteries would be £65.
Buy another £55 battery and you are in business. Total cost £120. Same price as your expensive battery option.
My pal runs a heater, autopilot, lights, instruments and fridge froma single 110 amphour domestic battery. Done several seasons with it. The difference is he has 80 watts of solar connected. It rarely gets discharged due to constant solar charge during the day.

Thanks did not realize they could be that cheap, maybe I am being lazy in not wanting the hassle of solar panels and regulators. Yup I know some one will crop up and tell me how easy they are, either way I do not want them they would clutter the boat look wrong and generally get in the way.

I don't know if there is a consensus and I for one am not going to tell you what to do or buy.
I have simply told you some truths about batteries and your use regime, based on considerable experience with a major manufacturer.
Two more things.
Gel and AGM are very different in construction, behaviour and charging requirements.
Pay little attention to life claims of cheap leisure batteries and if you think the warranty is comforting, read the small print.

Thanks again, not going to argue RE warranty.

I have been doing more home work, it seems that the "gel" battery I have is a Optima red top which appears to be the best of the best . It is survived well on the boat so I guess the charging must be about right for it. Certainly as a starter battery I would spend the money and replace like for like.

I think I will fit my old Landy starter battery in the boat to get me going again (once I get the headlining back up it will only be day sails till I get it sorted) and research a bit more batteries.

All advice still welcome..

 

[pvb]

Another constructive comment, thank you, I could question why some people post on the forums...

Most people who post questions on the forums are seeking for knowledge they don't possess themselves. You've amply demonstrated the truth of that.

 

[Plevier]

Optima is not gel it is a rather specialised type of AGM this is a huge difference.
They are very good and very expensive.
There are different versions for starting or cycling read the website http://www.optimabatteries.com/us/en/ and http://jci_.media.s3.amazonaws.com/1213/4333/7097/Battery_User_Guide.pdf.
Whether the cost is justified is a personal decision based on your useage. When the Optima starting battery that came with my boat expires I will almost certainly replace with an ordinary flooded one at less than half the price

 

[Trundlebug]

I am impressed there is no one shouting the odds, there is little positive advise one way or another agreeing or disagreeing...

As I understand the general consensus (if there is one) is:

We should spend about £400 on solar panels and battery management equipment and then to run the engine for a whilst to look after the batteries (which then might last 5-6 years?)...

If not we can expect our batteries to last 4 years...

As I have no plan on making the boat more complicated and heavier with more equipment to go wrong battery management is out along with extra batteries. Although I will submit to a slightly larger battery, as batteries do not like to deep cycling that seems sensible. So which would you choose?

Lead Acid Leisure 85 ah £55 500 cycles,
Lead acid Leisure 120 ah £115 500 cycles,
AGM (Like Gel) Leisure 85Ah £115 800 cycles,
AGM (Like Gel) Leisure 120Ah £145 800 cycles,

I can see why people go for banks of 85 amp batteries but I do not want the extra battery space is limited and she is wired for 1 domestic now not 2...

At the risk of being the first poster to give you a simple straight answer to your question, rather than tell you you asked the wrong question in the first place, my advice for your situation would be go for the biggest Ah capacity you can get for the lowest price.
In this case therefore, the 120Ah Lead acid for £120.

Although you may be able get a better price than that - only last year 110Ah batteries, probably the most common size and capacity (and therefore probably the best value) were selling for £70 or so.

If you are considering getting an old one from the dump, might I suggest a Megapulse unit to help desulphate it and provide some restored capacity. Although it does use some of the battery's own power, it does help sulphation which you are likely to suffer from given your usage and partial charging regime.

 

[KellysEye]

>I don't know if there is a consensus and I for one am not going to tell you what to do or buy.

I thought there was a general concensus because different batteries are designed for different tasks. Specifically Lead acid Deep Cycle golf cart batteries for domestic, Cold Cranking Amp batteries for engine, generator and anchor winch - most choose gel because no maintenance is needed.

 

[Plevier]

>I don't know if there is a consensus and I for one am not going to tell you what to do or buy.

I thought there was a general concensus because different batteries are designed for different tasks. Specifically Lead acid Deep Cycle golf cart batteries for domestic, Cold Cranking Amp batteries for engine, generator and anchor winch - most choose gel because no maintenance is needed.

I think you're missing the point a bit and over simplifying. Problem here is that the OP has such an unfavourable use/charge regime that spending money on something like a Trojan golf cart battery would probably be wasted.
Also we don't really know how intensively he's going to use it. Again Trojan money is arguably only worthwhile for heavy use even without the limitations of this particular case.
If anything the consensus here seems to be that he should get the cheapest possible.
My comment about not telling him what to do or buy was also in response to where he said (roughly) that he was being advised to spend lots of money on solar panels etc.
It's up to him, and again probably dependent on how much use it's going to get.
I disagree strongly with you that "most choose gel". I think very few choose gel and there aren't that many gels on offer now, and gel is a poor choice for most boat applications.
Many people are using AGM these days. Perhaps you think gel and AGM are the same, it's a common misconception? They are very different.

 

[onesea]

I believe one a 90ah agm leisure battery will arrive tomorrow...
http://www.alpha-batteries.co.uk/agm-gel-leisure-batteries/90-ah-ultra-plus-agm-leisure-battery/

Why?
1) I understand there is a "suggested" ratio of charging to do with amps on alternator and battery size. If you have a small an alternator and large bank of batteries they never get "fully" charged by alternator alone (I believe my alternator is only 20 amp's).
2) The way I use the boat the battery is often only charged for short periods in and out of berths, so I am more likely to get one battery full in this period than a bank of batteries.
3) AGM Batteries are said to charge quicker due lower internal resistance,
4) The published (I know IF you believe what they say) no of cycles for this AGM is 1000 compared with 300-400 for traditional leisure battery. So I hope to get a longer life, or keep a higher % of battery life for a longer period.
5) I have had such a good experience of the Optima Red Top.
6) At £20-£30 more expensive than a standard leisure of similar size it was not that much more expensive and I felt worth a gamble.
7) I have spent enough time and effort researching this project

Have I got it right? ask me back in a few years time...

 

[Plevier]

I believe one a 90ah agm leisure battery will arrive tomorrow...
http://www.alpha-batteries.co.uk/agm-gel-leisure-batteries/90-ah-ultra-plus-agm-leisure-battery/

Why?
1) I understand there is a "suggested" ratio of charging to do with amps on alternator and battery size. If you have a small an alternator and large bank of batteries they never get "fully" charged by alternator alone (I believe my alternator is only 20 amp's).
2) The way I use the boat the battery is often only charged for short periods in and out of berths, so I am more likely to get one battery full in this period than a bank of batteries.
3) AGM Batteries are said to charge quicker due lower internal resistance,
4) The published (I know IF you believe what they say) no of cycles for this AGM is 1000 compared with 300-400 for traditional leisure battery. So I hope to get a longer life, or keep a higher % of battery life for a longer period.
5) I have had such a good experience of the Optima Red Top.
6) At £20-£30 more expensive than a standard leisure of similar size it was not that much more expensive and I felt worth a gamble.
7) I have spent enough time and effort researching this project

Have I got it right? ask me back in a few years time...

Re yr no 1 - as I said before Normal advice is to have at least 10A charge current per 100Ah capacity for wets or gel and at least 15%, some makes call for 20%, for AGM (so your ratio is fine). However it's not really a matter of never getting fully charged, it's just that experience shows batteries seem to deteriorate more with very low charge rates. I can't give you a fundamental reason but it's obviously related to sulphate conversion. Similarly it is much better to recharge immediately after discharge. The battery will only take the full charging current (at standard alternator voltage) up to a moderate state of charge. Getting it up to full charge from there takes at least a number of hours.
2 - you will not keep any battery fully charged this way.
3 - yes they will get up to (say) 80% SOC quicker but it still takes some hours after that.
4 - time will tell.
5,6 - Optimas - which have a unique construction very different from what you have bought - do seem very resilient albeit at a pretty startling price level. You can't draw too many comparisons.

You may well have made an appropriate choice but don't expect miracles!

 

[geem]

My cheap Numax leisure batteries froma caravan shop have been installed 7 years. They have solar panels connected via a regulator. They rarely get below 70% due to the solar panels. This seems to be contrary to your recommendations. I am no expert but it seems to work well.