Deep Cycle Battery

LeonF

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Think it might be time to replace my domestic battery. Engine start is a Numax leisure battery. Wondering what the experts here think of replacing the domestic with a true deep cycle battery with no cranking ability ? Like this one. http://batterymegastore.co.uk/product/DC24/. I don't have an Adverc or Sterling type charger, just a 55 ah alternator, but there is a Volvo gizmo which, I believe, senses which battery is in greater need of charge. Could I have problems with two different types of batteries ?
 

Seajet

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As I understand it ( and others will understand 'it' a lot bettter ! ) you won't have trouble with dissimilar batteries, but may well be better off trickle charging the domestic one with a solar panel etc.

There are various marine intelligent charging / regulating gizmo's too if wishing to optimise.
 

PeterGibbs

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Think it might be time to replace my domestic battery. Engine start is a Numax leisure battery. Wondering what the experts here think of replacing the domestic with a true deep cycle battery with no cranking ability ? Like this one. http://batterymegastore.co.uk/product/DC24/. I don't have an Adverc or Sterling type charger, just a 55 ah alternator, but there is a Volvo gizmo which, I believe, senses which battery is in greater need of charge. Could I have problems with two different types of batteries ?

Charging is the secret to good battery life. Alternative battery types (to lead acid) offer little advantage to the average cruiser.

Starter batteries can last a long time in service (mine is 12 years old and still good) because they are discharged a little and rapidly put back in shape.

Service batteries cannot help but be more drained so require better charging if they are to do better than just 2-3 seasons. This requires heavy current occasionally, and most alternators cannot respond to this. So a variable stage charger is a good investment: a solar panel cannot replicate this regime, it's too puny. You can fit one to the alternator output or in a shore power setup: on my boat I put one in each charger source and it is a good investment.

At £200 a pop such chargers might sound like a chandler's dream, but I can assure you they are worth their cost - and will amortize if you keep the boat for several seasons. Don't look on them as just saving the cost of prematurely renewing service batteries, just think of the much better reliability you get from the power source behind all your important electrical systems!

PWG
 

LeonF

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Peter thanks for your detailed reply. On a previous boat I had an Adverc fitted and replaced the standard lead acids with AGMs, but when fully charged via the mains, when they continued to charge via the alternator when motoring, the output went upto 16v, and I never managed to get a definitive response from the battery manufacturers or Adverc so replaced them for fear of frying them.

My current domestic battery is a Trojan Deep cycle with cranking ability, and I have occasionally used it to start the engine. I have a feeling it is starting to lose it's charge more quickly after 7 years use, and my question was to see if there are any benefits to changing the domestic battery to one that is purely traction, with, as I understand it, thicker plates and better holding qualities.
 

LeonF

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Well they say it has no cca ability, so I thought it might be different. If not then I'll just match it with another Trojan, or the Numax I got from Tanya batteries that seems to be offering excellent service. I suppose there are advantages to having a domestic with cca in case one runs the engine start battery down by mistake.
 

Plevier

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I very much doubt that, at that price, that is a true deep cycle battery. Almost certainly just a leisure battery......nothing wrong with that, but it won't be what they are pretending it is.

I agree completely with that.
Bear in mind there are no real definitions of "leisure" and "traction" batteries. They differ from automotive start batteries basically in having thicker plates and different separation but it's all a matter of degree. You could argue it's fairer to look at the start battery as the special one; its construction is adapted from the general to optimise it for high current short shallow discharges.
A battery that looks and costs like the one you link to is most likely using truck battery type plates typically 2-3mm thick; a typical starter battery plate will be more like 1mm thick; an industrial flat plate traction battery plate maybe 6mm thick. The best traction batteries are a different construction altogether (tubular plates) but that's a whole different ball game of cost and size.
The separators in start batteries are very thin and porous for low internal resistance, quick diffusion and high cranking current capacity. Leisure/traction will have more robust separation to guard against shorts from dendritic growths etc.
There's no reason you shouldn't use a leisure battery for starting; it just won't give much current relative to its capacity compare with a start optimised battery. It's marketing not technology.
If you are going to regularly cycle a "leisure" battery then you want to recharge it quickly with a multi stage charger. That means you are going to lose some water particularly if it's in a warm climate. I therefore distrust any wet leisure battery claiming to be sealed maintenance free. A car battery shallow discharged and then recharged only at alternator voltage (ca 14V) (and incidentally in most cases never getting above about 85% charge state) may get through its life without water addition but a cycled battery with a multi rate charger? No. The small print normally says "MF if not charged above 14.2V" or something like that; that's no good to you.
This sort of battery is certainly better than a starter battery for boats/motorhomes getting a deep discharge occasionally but not daily.
If you are really going to hammer the battery, pay up for a Trojan or Rolls or similar. Most people don't need them but maybe you do.
Lead calcium has the advantage of lower water loss, but lead antimony always used to be regarded as having better deep cycling resistance. (Chemically they are both lead acid; the difference is just in what is alloyed with the lead to give it mechanical strength, typically 0.1% calcium or 1.5% antimony. Traces of silver and tin may also be used - Varta make a big play about silver and they make excellent batteries. I think Varta and Bosch are the same these days.)
By and large you get what you pay for. Look at the weight as well. For a given capacity (or more dramatically for a given cranking current), the heavier the battery, the longer it's likely to last when cycled because it has more lead in it in thicker plates. It should cost more for the same reason.
I have to admit my battery industry experience is a good few years ago and advances will have been made but personally I would still never use AGM for repeated deep cycling, despite having been involved in the launch of the first long life AGM battery range. They make wonderful starter batteries though.
Don't use gel for any application! Gel and AGM are NOT the same thing.

One qualification to what I said - I suppose you might possibly run into a heat build up problem if you used a leisure type battery to crank a non-starting engine for a very long time but it's highly unlikely and would result from bad design! Normal starts would be no problem.
 
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Well they say it has no cca ability, so I thought it might be different.

I thought that at first but then I realised that by saying "N/A" (which they also say to describe the weight!) they were simply witholding the information.

Pound to a penny that this is exactly the same* battery as the leisure battery which they list a little further down at around £20 less. The size and capacity are the same; they've just put "N/A" against weight and CGA to make them look different.



* but the label is a different colour!
 

charles_reed

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Think it might be time to replace my domestic battery. Engine start is a Numax leisure battery. Wondering what the experts here think of replacing the domestic with a true deep cycle battery with no cranking ability ? Like this one. http://batterymegastore.co.uk/product/DC24/. I don't have an Adverc or Sterling type charger, just a 55 ah alternator, but there is a Volvo gizmo which, I believe, senses which battery is in greater need of charge. Could I have problems with two different types of batteries ?
Specification looks very similar to the Delco lead-calcium batteries - so not comparable to a genuine deep-cycle traction battery.
As already pointed out it's a leisure battery by another name.

I've finally got shot of the last of my Delco batteries; - on the + side they certainly last a long time (10 years) but the negative is that they're slow to accept a charge and unwilling to give it up when they are charged.

The advert looks to me like a smoke&mirror attempt to gull, especially in view of the with-held information.
 

GrahamM376

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I've found that price has little to do with performance and that some makers claims are not to be believed.

I replaced our four "cheap at the time 110AH leisure batteries" with Exide Enersol 130's, supposedly made for solar systems, at 3-4 times the price. 2 domestic banks each 260AH, separate engine start.

They're charged mainly by 200W solar + Aerogen, rarely go below 80% charge overnight (fridge running 24/7) and have only lasted 4 years. Will revert to cheapies from motor factors - NOT chandlers.
 
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WILLOW3......I have to admit my battery industry experience is a good few years ago and advances will have been made but personally I would still never use AGM for repeated deep cycling, despite having been involved in the launch of the first long life AGM battery range. ......

Good detailed reply - BUT you seem to totally dismiss AGMs. Like most batteries you get what you pay for and not all AGMs are the same.

My Lifeline AGMs are now 7 years old and I highly recommend them to any serious cruising boat. Just because they can't be charged higher than 14.2 volts doesn't limited their rate of charge, because its the current that they can accept that makes them charge 30% faster. A normal 100 Ah wet cell should be charged at a maximum of 25% of its capacity - i.e. 25 amps, but Lifeline AGMs because of their very low resistance can have an in-rush charge of up to 500% - i.e. 500 amps. That may not be very practical, but the low resistance does mean they charge faster even at 14.2 volts. To optimise ours we have a DC genny that charges at 280 amps so we are really getting the most out of their fast charge capability.

Other major benefits is they can be mounted upside down or on their side to save space, size per Ah they are smaller, and they don't gas even when warm because there is no heat build up when charging or discharging due again to their low internal restance. They are also the only sealed battery I know that can be equalised because they are designed so that the gas recombines in the battery.

There's a lot going for these batteries and it takes a huge 35 page user manual to explain all the benifits. Worth Googling.
 
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McSalty

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1st: Am the new kid on the block - so please forgive me if I should have started a seperate thread ...but it seems like my Q fits right in here:

2nd: Just bought a "boat" (well, it's a tad big for being labeled "boat" - but so be it.) It has been sitting totally neglected by previous owner for some 6 years in a local marina...
(Unfortunately, the only thing I did NOT check prior to the purchase was if the marina fees are paid to date - and, needless to say they are not, so I am being hit with a huge bill I did not anticipate... but thats a different story alltogether)

3rd: The service batteries have been new when the boat was abandoned. Now, when you look inside they are totally dry and the lead-cells seems a bit "deformed".
What puzzled me is the fact, that they are 6V and not, as I had expected 12V

So, I have 12 x 6V 190Ah deep cycle Trojan TE35 Batteries which most likely are "dead".
In view of the unxepected expense (see above) I need to find a way to revive them, or else a new set of domestic Batteries alone will be some € 10,000
uhh umm.

Any good ideas here how to go about giving them a second chance short of simply filling destilled water, leaving them lids open, covering with a rag, and have the charger go to work?
Is my hope totally "off" that with pushing them through a bunch of cycles I could bring them back to life?
 

Modulation

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Don't know too much about battery technology and unwilling to spend the time learning it, so after years of frustration with "leisure deep cycle" batteries not accepting/holding charge, I decided to replace with two Trojan 105 lead acid jobs. Did it 4 years ago and never a problem since, using a simple car charger as back up and the boats original 15 year old alternator.
 

KellysEye

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The best deep cycle batteries are Trojan. Most people buy 2 x 6 volt and wire them in series. If you don't have the space 12 v are also available. Cranking battteries should not be used for domestic purposes because they are designed only for starting engines. The Trojans are lead acid which need a different charging regime fom gel etc thus you need a smart charger that allows you to set battery type.
 

Plevier

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Good detailed reply - BUT you seem to totally dismiss AGMs. Like most batteries you get what you pay for and not all AGMs are the same.

My Lifeline AGMs are now 7 years old and I highly recommend them to any serious cruising boat. Just because they can't be charged higher than 14.2 volts doesn't limited their rate of charge, because its the current that they can accept that makes them charge 30% faster. A normal 100 Ah wet cell should be charged at a maximum of 25% of its capacity - i.e. 25 amps, but Lifeline AGMs because of their very low resistance can have an in-rush charge of up to 500% - i.e. 500 amps. That may not be very practical, but the low resistance does mean they charge faster even at 14.2 volts. To optimise ours we have a DC genny that charges at 280 amps so we are really getting the most out of their fast charge capability.

Other major benefits is they can be mounted upside down or on their side to save space, size per Ah they are smaller, and they don't gas even when warm because there is no heat build up when charging or discharging due again to their low internal restance. They are also the only sealed battery I know that can be equalised because they are designed so that the gas recombines in the battery.

There's a lot going for these batteries and it takes a huge 35 page user manual to explain all the benifits. Worth Googling.

No I don't dismiss AGMs at all. I know they vary in quality. The ones I was involved with were top of the market.
They are great in their place but I would not use them for regular deep cycling. They will not give the same life.
Yes they charge more rapidly than conventional batteries at 14.2V or thereabouts but only up to 80-85% capacity. The rest will take a couple of days (ish).
Lifeline is not the only battery to recombine. That is the whole point of starved electrolyte stoichiometrically balanced batteries. They all do, that's why they don't gas externally. I can give you all the chemistry if you like! But the recombination rate is limited.
Frankly I distrust Lifeline's claims. Among other things they say of their marine AGM batteries

Deep Cycle (thick positive plates to provide real deep cycle performance)
Outstanding cranking performance (aircraft cell construction lowers internal resistance)

Those two characteristics are mutually exclusive.

If you read their manual it limits you to 14.4V for regular charging. They mention 15.5V "should only be done when the battery is showing symptoms of capacity loss". That is standard technique, just not usually mentioned because you don't want users to do it excessively. It's the manufacturer's trick up the sleeve when a battery is below capacity! Believe me, it will gas during this charge and if you do it more than once a year or so you will shorten the battery life.

Nowhere do they give a claimed cycle life for these "deep cycle AGM" batteries.

I suggest taking their claims with a pinch of salt. Their AGMs are no better than other good ones, they are not unique.

PS Have just found page where they do claim cycle life figures - 1,100 cycles to 50% DOD and 500 cycles to 100% DOD. It's not clear what they mean by 50% and 100% DOD though. In the sizing guide they say the battery should be sized so that you never discharge more than 50% of full rated capacity. If in claiming the cycle life they are working to this rule, so that 100% DOD would actually mean 50% of rated capacity and 50% would mean 25% - I hope you follow what I mean! - then these figures are moderately ambitious but not silly.

There are some very selective claims in their 35 page manual e.g. it claims that at 0.1" thick their plates are "extra thick" and other manufacturers only use half that thickness. That is only true when you compare with lightweight stuff like Yuasa NP (just as an example, not singling them out, they are fine batteries for the right purposes like fire alarms) - other long life industrial SLAs are typically around 0.1" as well, if not more.

Lifeline are made by Concorde which is a long established aircraft specialist battery maker. They are OK but have never led the field. Long after we had had AGM batteries approved for the Harrier and AV8B and H-S125 they were still arguing that SLA really wasn't suitable for aircraft!
 
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ORIGINALLY POSTED BY WILLOW3
No I don't dismiss AGMs at all. .............They are great in their place but I would not use them for regular deep cycling. They will not give the same life..........Nowhere do they give a claimed cycle life for these "deep cycle AGM" batteries.
Lifeline publish figures in their user manual. 5000 cycles for a 10% depth of discsharge (DOD), 3000 cycles for a 20% DOD, and 1000 cycles for a 50% DOD. Research online (http://www.windsun.com/Batteries/Battery_FAQ.htm) suggests "...most golf cart batteries are rated for about 550 cycles to 50% discharge - which equates to about 2 years." Lifeline have a 5 year warranty. Seems to me that they come out well on cycle times.

Yes they charge more rapidly than conventional batteries at 14.2V or thereabouts but only up to 80-85% capacity. The rest will take a couple of days (ish).

All batteries take a very long time to charge from 85% to 100%, but because of low internal resistance Lifelines will get to 100% much quicker.

Lifeline is not the only battery to recombine. That is the whole point of starved electrolyte stoichiometrically balanced batteries. They all do, that's why they don't gas externally. I can give you all the chemistry if you like! But the recombination rate is limited.

The gassing is rated as "negligible unless severely overcharged." The recombination rate is 99%.

Frankly I distrust Lifeline's claims. Among other things they say of their marine AGM batteries

Deep Cycle (thick positive plates to provide real deep cycle performance)
Outstanding cranking performance (aircraft cell construction lowers internal resistance)

Those two characteristics are mutually exclusive.
I would suggest that because of their construction and the closeness of the plates, it is their very low internal resistance (the main factor in their fast and very high current charging) that allows Deep Cycle and outstanding cranking performance in the same battery.

I suggest taking their claims with a pinch of salt. Their AGMs are no better than other good ones, they are not unique.

Then why is Lifeline trusted on today's front line ambulances, police and fire trucks, large aircraft manufacturers and even on Ellen MacArthur's Kingfisher Yacht and her Trimaran, B&Q.(http://www.power-store.com/view-item.asp?itemid=1685&id=217&)

I have no links with Lifeline but all the other cruisers I have spoken with are very happy with their choice.
 

Plevier

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sailinglegend, I am not saying that Lifeline batteries are rubbish. I am saying they are no better than other industrial quality SLAs. Just about everything they claim as unique to them is in fact perfectly standard - no gassing, turn them upside down if you want, higher power density, lower self discharge (although again they give completely unrealistic figures for alternative batteries), better charge acceptance. It's all normal and Lifeline/Concorde are not pioneers, in fact they were quite late adopters of the technology.
It is a small company with a tiny market share overall and so they go for niches. As regards some of their glamorous clients I suspect product placement is a factor.
I still say, if you want to really thrash your batteries, AGM is not the answer.
If you want relatively small, lightweight, non-spill ones, are not going to work them so hard and don't mind the extra cost, they are fine.
 

McSalty

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Pls forgive me for "re-posting" this, ...my account just got approved and I guess nobody will scroll up to discover my posting there.
_____________________ (this is what I wrote 2days ago) ____________

1st: Am the new kid on the block - so please forgive me if I should have started a seperate thread ...but it seems like my Q fits right in here:

2nd: Just bought a "boat" (well, it's a tad big for being labeled "boat" - but so be it.) It has been sitting totally neglected by previous owner for some 6 years in a local marina...
(Unfortunately, the only thing I did NOT check prior to the purchase was if the marina fees are paid to date - and, needless to say they are not, so I am being hit with a huge bill I did not anticipate... but thats a different story alltogether)

3rd: The service batteries have been new when the boat was abandoned. Now, when you look inside they are totally dry and the lead-cells seems a bit "deformed".
What puzzled me is the fact, that they are 6V and not, as I had expected 12V

So, I have 12 x 6V 190Ah deep cycle Trojan TE35 Batteries which most likely are "dead".
In view of the unxepected expense (see above) I need to find a way to revive them, or else a new set of domestic Batteries alone will be some € 10,000
uhh umm.

Any good ideas here how to go about giving them a second chance short of simply filling destilled water, leaving them lids open, covering with a rag, and have the charger go to work?
Is my hope totally "off" that with pushing them through a bunch of cycles I could bring them back to life?
 

Plevier

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3rd: The service batteries have been new when the boat was abandoned. Now, when you look inside they are totally dry and the lead-cells seems a bit "deformed".

So, I have 12 x 6V 190Ah deep cycle Trojan TE35 Batteries which most likely are "dead".

Any good ideas here how to go about giving them a second chance short of simply filling destilled water, leaving them lids open, covering with a rag, and have the charger go to work?

Virtually no chance at all.
If you want to try, measure first to check for short circuits which are quite likely and might make your charger very unhappy. Sorry!
 

dinwood

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I know we all like to think we've made the right choices and will go out of our way to find evidence that we have, but...
I dug deep into the bank and replaced our domestic batteries with 630Ah of Lifeline AGMs a year ago. We live aboard and like to be independant of external power as much as we can. I have to say I am extremely pleased with our choice. This is our 4th set of batteries on the 2 boats we've owned, and it is the first time that I've been completely relaxed about the availability of power, with the batteries sucking up as much power as the solar panels and Duogen can produce. I've had a few worries about engine charging when the Adverc alternator manager didn't give out enough volts in the heat of last summer (in the E Med), and having fixed that with Adverc's help, with it giving out too many volts in the cold. But the batteries have been great, worth every penny imho.
 
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