Dual purpose batteries or hybrid batteries?

[Humblebee]

I read the recent threads on battery replacement and remain a bit confused on one point.
One contributor, whom I respect and who seems to know his stuff, says there is no such thing as a hybrid battery, it is either a starter battery or leisure battery. He also identifies Hankook dual purpose batteries as good value.
So, what is the difference between a hybrid battery and a dual purpose one?

 

[BabaYaga]

Several manufacturers (Varta, Exide, Numax...) market 'dual purpose' batteries, which means they are suitable for engine cranking as well as for general supply for equipment. As far as I understand this concept is based on, among other things, designing the plates so that they are thin enough to give a reasonably high current but at the same time thick enough to give acceptable cycling performance etc. A bit of a compromise, in other words. Ten or fifteen years ago the same type of battery used to be called 'leisure battery'.
It would not be surprising if some manufacturer decided to call their dual purpose battery a 'hybrid' (because it is basically what it is), but I don't know if anyone does?

 

[PaulRainbow]

Various manufacturers and/or battery retailers make all sorts of claims regarding batteries, some of which are outright lies.

"Marine" batteries are fictional, there is no such thing.

"Hybrid" batteries don't exist either. You cannot combine a starter battery and a deep cycle battery, it's one or the other.

"Dual purpose" is just a play on words, IMO trying to deceive you into thinking it is something special, as in it's a starter battery and a deep cycle battery in one, which it is not (they don't exist. It could be argued that it is "Dual purpose" because you can use it for two purposes, to start an engine and to run domestic equipment. But you can do that with the battery from your car, it's still starter battery though. You can start the engine with deep cycle batteries, but they are still only deep cycle batteries and they are not best suited to engine starting.

"Leisure" batteries are starter batteries, they are not deep cycle. They usually have some additional plate support, but that's about it. There doesn't seem to be anything misleading in the term "leisure battery", as long as we remember it's a beefed up starter battery.

I have been known to mention Hankook batteries as being good value (IMO). I have fitted many of these (two pairs on different boats just today), my own boat has three 130ah leisure batteries fitted as the domestic bank. I find they last well enough (mine are four years old and still performing well) and are reasonably priced. Battery Megastore prices seem OK, but i find it very annoying that they insist on referring to some models as "deep cycle", when they absolutely are not.

 

[William_H]

As said batteries can be optimised for cold crank amps (start) or for deep cycle service. I suspect that a starter optimised battery while it may supply a useful amount of capacity at low drain rate, might not survive so long being discharged deeply often. It however seems to me that a large battery optimised for deep cycle work will happily supply a lot of current for starting a relatively small engine. Not because it is optimised for CCA but simply because it is big. A car battery is physically quite small for the CCA so there is the clue if you buy a 100AH deep cycle it is big and heavy. ol'will

 

[[2068]]

There is such a thing as a dual purpose battery.

e.g.
XDC31MF Numax Leisure Battery 12V 105Ah

Somewhat lower CCA, but thicker plates, and hopefully better deep discharge characteristics.

 

[Momac]

I am about to buy a pair of Hankook 130Ah batteries . My domestic bank is used to start the starboard engine so the dual purpose type seems to fit my needs.
I considered the Exide 140Ah but unfortunately they are a little too tall for my battery box.

My present 110Ah Hankook batteries are 4 years old and have little capacity remaining despite not having been abused - but they were cheap. I hope the larger Hankok 130Ah versions may last a little longer if given the same treatment .

I guess a new fridge might use less energy - but they are about £600.

 

[Porthandbuoy]

Are the batteries fitted to vehicles with ‘stop/start’ technology any different? They seem to cost more than a regular car battery!

 

[PaulRainbow]

There is such a thing as a dual purpose battery.

e.g.
XDC31MF Numax Leisure Battery 12V 105Ah

Somewhat lower CCA, but thicker plates, and hopefully better deep discharge characteristics.

How thick are the plates ?

Why would it have any "deep discharge characteristics", it isn't a deep discharge battery.

 

[PaulRainbow]

Are the batteries fitted to vehicles with ‘stop/start’ technology any different? They seem to cost more than a regular car battery!

Yes, they are different. Some vehicles are fitted with ECM batteries, most use AGM. No reason not to use AGM on a boat, they are often fitted as starter or bow thruster batteries and are also suitable as domestic batteries.

 

[Stemar]

No reason not to use AGM on a boat

Apart from the cost. What advantages do they have over leisure domestic batteries and a plain vanilla car battery as a starter for Joe Bloggs on his AWB/MAB?

 

[andsarkit]

It's very difficult to see beyond the advertising hype on dual purpose leisure batteries. I eventually got Varta dual purpose batteries as they were willing to publish a spec of 200 cycles at 50% D.O.D. Certainly enough for a weekend sailor like me. None of the other manufacturers seem to publish any data. Almost all the warranties exclude sulphation and over discharge so not really very useful.
My little Yanmar only needs 80A for a few seconds to start so CCA is not really an issue for any battery.

 

[PaulRainbow]

Apart from the cost. What advantages do they have over leisure domestic batteries and a plain vanilla car battery as a starter for Joe Bloggs on his AWB/MAB?

Prices have come down a lot recently. Depending on use, there may or may not be an advantage, there isn't a one battery fits all solution.

 

[BabaYaga]

"Dual purpose" is just a play on words, IMO trying to deceive you into thinking it is something special, as in it's a starter battery and a deep cycle battery in one, which it is not (they don't exist. It could be argued that it is "Dual purpose" because you can use it for two purposes, to start an engine and to run domestic equipment. But you can do that with the battery from your car, it's still starter battery though. You can start the engine with deep cycle batteries, but they are still only deep cycle batteries and they are not best suited to engine starting.

"Leisure" batteries are starter batteries, they are not deep cycle. They usually have some additional plate support, but that's about it. There doesn't seem to be anything misleading in the term "leisure battery", as long as we remember it's a beefed up starter battery.

I would question this advice. Are you saying that there is no benefit at all to the boat owner from 'additional plate support' or other means of 'beefing up'?
I have been told by an industry insider (Exide) that the plates of a dual purpose flooded battery indeed are thicker and more robust than those of a typical starter battery. Could just be another lie, of course...
But is there any technical reason why such a battery could not be manufactured? Or are batteries by nature always either starter type or deep cycle type? (I don't think manufacturers in general claim that their dual purpose or leisure batteries are just as good as their deep cycle batteries when it comes to cycling performance).
I fear your advice might make some people draw the conclusion that a cheap starter battery is just as good as any for domestic use.

For what it is worth, I have just retired a bank of three of these
Exide ER350 DUAL Leisure Battery 80Ah (Porta Power PP75)
installed in 2011. Still functioning well, but of course with somewhat reduced capacity after so such a long time.
I doubt that I would have got as many years out of three typical starter batteries.

 

[andsarkit]

Those Exide batteries seem good according the the data and the AGM version appears to have a significant advantage.

 

[PaulRainbow]

I would question this advice.

What advice ? i don't recall giving any in that post.

Are you saying that there is no benefit at all to the boat owner from 'additional plate support' or other means of 'beefing up'?

I'm saying what i typed, no need for you to add anything extra.

I have been told by an industry insider (Exide) that the plates of a dual purpose flooded battery indeed are thicker and more robust than those of a typical starter battery. Could just be another lie, of course...

Recently replaced a set of Exide batteries, on a 4 year old boat.

But is there any technical reason why such a battery could not be manufactured? Or are batteries by nature always either starter type or deep cycle type? (I don't think manufacturers in general claim that their dual purpose or leisure batteries are just as good as their deep cycle batteries when it comes to cycling performance).
I fear your advice might make some people draw the conclusion that a cheap starter battery is just as good as any for domestic use.

Again, what "advice" ? Who have i advised and what advice did i give ?

For what it is worth, I have just retired a bank of three of these
Exide ER350 DUAL Leisure Battery 80Ah (Porta Power PP75)
installed in 2011. Still functioning well, but of course with somewhat reduced capacity after so such a long time.
I doubt that I would have got as many years out of three typical starter batteries.

I cannot see where i suggested that anyone should fit "typical starter batteries". Are you sure you're reading the same forum that i posted to ?

I do seem to recall mentioning that my own boat has three 130ah leisure batteries that are 4 years old and still working well enough. I also said "there isn't a one battery fits all solution. "

 

[[2068]]

How thick are the plates ?

Who cares exactly how thick the plates are?
The point is that it is a dual purpose battery that is capable of starting an engine and being used as a domestic power source.
For a purely domestic power bank I would have Trojans or similar.

MANBAT REINVENTS ITS LEISURE RANGE | Manbat

 

[PaulRainbow]

Who cares how thick the plates are?
The point is that it is a dual purpose battery that is capable of starting an engine and being used as a domestic power source.

As is your car battery. As is a true deep cycle battery.

Bit like saying my tap produces dual purpose water, it can be used for drinking and washing.

It's a starter battery !

 

[rotrax]

Yes, they are different. Some vehicles are fitted with ECM batteries, most use AGM. No reason not to use AGM on a boat, they are often fitted as starter or bow thruster batteries and are also suitable as domestic batteries.

Our previous vessel had four 110 AH Lifelines. A well respected quality make of AGM Battery. By the date codes they were 12 years old when we sold her and needed replacing.

Our current boat, same make, American, was supplied with five 110 AH Lifeline batteries. Due to neglect before we got her, four were replaced four years ago. I have since added a sixth, for the genset. It was a relatively cheap spiral wound AGM, of Chinese source I believe. The boat was laid up in October, monthly charging regime of four hours. The genset battery does not charge from the Charles 60 AMP Charger, only from the genset alternator. So, no charge for eight months to that particular battery.

When we splashed two weeks ago - eight months later - the genset fired up right away. And has several times since.

I think AGM's are great. They certainly work for us. We live aboard most seasons for five months, rarely on shore power.

The 8KW Westerbeke genset is used when off shorepower for an hour or so every morning for hot water and battery charging.

We have a theoretical 660 AH. I suspect half of that before the batteries become discharged too far.

Four years, never seen the meter read below 12.5 V. Normally 12.7 or 12.8 V.

That is good enough for me.

No solar or wind, two very large keel cooled fridges, Dometic 40 Litre freezer box, all internal lamps LED.

Coming from a very simple canal narrow boat with just one battery we learned long ago to be frugal with electrical power.

 

[[2068]]

As is your car battery. As is a true deep cycle battery.
Bit like saying my tap produces dual purpose water, it can be used for drinking and washing.
It's a starter battery !

A true deep cycle battery such as a Trojan does not meet the CCA requirements of my engine.

Horses for courses:
I have a starter battery for the bow thruster with a high CCA.
Something very similar to those yellow tops for starting and domestics.
And if I had a purely domestic bank I would use Trojans or similar.

 

[lw395]

Different batteries are optimised in different ways to meet different specs.
There are subtle differences to the alloying of the lead, the structure of the plates, plate thickness, separation.
No two batteries need perform the same.
How much is advertising hype and how much is genuine optimisation, believe what you want.

One reason other people have not so far mentioned for choosing an AGM or sealed battery for a yacht is the yacht may get heeled a lot or even rolled. Some racing regs require or advise batteries which won't leak after a knockdown.

When it comes to working out what's most cost effective, it's difficult. because so many boats are used infrequently and the batteries tend to die of neglect, overcharging or plain old age rather than number of cycles.