leisure battery saga sorted....

[Dezi]

AJS,

Keeping it simple a leisure battery should not be used for starting engines & an engine battery should not be used for EFFECTIVE leisure use. Only swap in emergencies.
The chart above shows 12v is 100% at 12.7 & a 24v at 24.4
Then just work down the readings. Try not to let your batteries drop below % 30 if you want them to last.

Dezi

 

[PaulC]

That's very good theory, but what about so called leisure batteries that are on the market? Are they genuine or just labeled that way? And what happens if you treat one of these "leisure" batteries as a deep cycle one?

 

[Deleted member 3011]

I have spoken to an electronics lecturer who informs me that, in simple terms, leisure batteries have lots of thin plates which maximise the electrolyte / plate interface giving long life but a tendency to deform under high current demand, whereas starter batteries have fewer, thick plates that supply peak power but lose voltage more rapidly on constant drain (though they partially recover if rested). This made sense to me and I don't see why one would be so much more to manufacture than the other.
Andy

From Wikipedia

The key structural difference between deep cycle batteries and cranking batteries are the lead plates, which are solid in deep-cycle batteries and composed of porous sponge-like plates in starting batteries. Some batteries that are labelled "deep-cycle" do not possess these solid lead plates, however, and are actually "hybrid" batteries. While a deep-cycle battery is designed to discharge down to as much as 20% of its charge capacity over several cycles, companies recommend that a hybrid battery not be discharged beyond 50% of its capacity.

From Outback Marine

Starting Batteries
Starting batteries need to supply heavy current (or high power) for a short period of time. Starting a healthy engine consumes only a small amount of overall energy. For example, the energy required to crank a 120-amp starter motor for 5 seconds would be around 0.17 amphours. (5 seconds x 120-amps = .17 amp-hours). - Or about the same amount of energy required to run an anchor light for 10 minutes.

They have a thin plate construction to maximise the plate surface area to efficiently deliver a burst of current suitable for starting. When a battery is charged and discharged, a small amount of plate material is eroded for each cycle - this is one of the wear out mechanisms for a lead-acid battery. The thin plate construction is not so much an issue for starting type batteries because they're designed to be kept fully charged all of the time.

House Batteries
A house battery on the other hand is required to deliver lower amps for longer periods of time before charging. Deep-cycle batteries have thicker plates that allow them to withstand many more discharge/charge cycles before wearing out. It is important to correctly size the house battery system for the application.

 

[oldiebutgoodie]

That is not only an opinion; it is a fact !
The only real deep cycle batteries are the so called 'boat batteries' and they are too big for a MH. Just don't let your battery drop under 11 V and you are OK for years.

I am slightly confused over the above statement - my Vetus boat batteries are exactly the same size as normal batteries albeit heavier. What do you mean 'too big'?

 

[Dezi]

Tony is correct in the information supplied, but I suspect that it is dated. The two 110 amp Squadron leisure batteries
we have in the new murvi are actually smaller than the 85 amp ones that were in the old murvi when we purchased it in 1999 - time moves on and components become more efficient.

Reminds of the old joke about the electronics factory. They were so successful that they moved into smaller premises.

Dezi

 

[PaulC]

But what are we buying in the shops? I now think there is no legel definition of a leisure battery. Where are is with a deep cycle battery I suspect! If it's not written stone, but it went to court I think that would be the case. So a leisure battery could be anything!

 

[Deleted member 3011]

"Leisure" battery seems to be a peculiarly British (or maybe European) term.
I'm used to "Starting", "Deep Cycle" or "Marine" classifications - with many being convinced that the marine type are a compromise that is not particularly good for anything - although the mariners swear by them.

I agree that there is a lot of overlap and if you include in the equation the creative puffery employed by many manufacturers and retailers, it is not surprising that most customers are left in the dark. In some cases the retailers haven't much of a clue either so it becomes the blind leading the blind with the customer paying as usual.

For many weekend warriors, the extra cost of true deep cycle may not be warranted, especially if EHU is usually available or there is a bit of driving done every couple of days. Just flog the battery and when it fails, pull into the nearest discount store and grab another one. Full-timers do need to do the research and spend the big bucks for a balanced system but there are not many of us in that category.

 

[oldiebutgoodie]

"Leisure" battery seems to be a peculiarly British (or maybe European) term.
I'm used to "Starting", "Deep Cycle" or "Marine" classifications - with many being convinced that the marine type are a compromise that is not particularly good for anything - although the mariners swear by them.

Having had a pair of Vetus marine batteries in my boat last for 11 years I for one am convinced of their value and reliability in a marine situation but could not justify the cost for my vans!

 

[jojo]

split relay chargers

Hi
I have had my ducato camper for a few years now and fitted a split relay charger,it's been on now for two years.I have two good car batteries that are being charged each time i start the engine,the power goes to the main battery,then when that is charged excess charge goes to them,no power comes from the main battery,so the motor will always start.I think it cost about £35 and half hour to fit,hope this helps someone.