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BATTERY QUESTION
Posted: Tue Jan 05, 2010 12:01 pm
by falcoron
Hi And happy new year to all!
Wondering about a leisure battery and are these actually different from a standard battery? I know these all have various AH ratings but would a standard battery do the job?
reason i ask is i can get std batteries at good prices but the leisure type seem to be twice the price.
What size ( HxWxL) Is a leisure battery for a bongo and what is the best AH to get?
Cheers
Re: BATTERY QUESTION
Posted: Tue Jan 05, 2010 12:34 pm
by markdogwalker
hi
iam not an expert on batteries, but my understanding is ,
that allthough not recomended you can fully discharge a leisure battery . if you fully discharge a normal battery you can cause damage to it , plus leisure batteries are sealed , normal batteries can give of fumes , ( bad if you have it inside the bongo ) unless you vent it .
someone wll no doubt be along with more info on how normal batteries are designed for cold cranking power for starting engines , and more technical advice
hope this helps
Re: BATTERY QUESTION
Posted: Tue Jan 05, 2010 12:39 pm
by francophile1947
You can use a starter battery as a leisure battery (I have done so), but rumour has it that they don't like being discharged to the extent that a leisure battery gets discharged, so the life will be seriously shortened. Personally I never found it to be a problem
What size - how big is your battery tray? Apparently, if you fit a larger capacity (Amp/Hr) leisure battery than your starter battery, they will both only charge up to the capacity of the smaller battery - I have an 85Amp/Hr leisure battery, but loads fit 110Amp/Hr.
Re: BATTERY QUESTION
Posted: Tue Jan 05, 2010 12:40 pm
by dave_aber
It's all about the internal structure.
Starting batteries are made of lots of thin plates to give maximum surface area and thus highest CCA for starting. Running these flat is bad for them. Plates become eroded etc.
Leisure batteries have fewer, thicker plates, which give better overall capacity but lower max CCA. These are more tolerant of running right down to flat. Still not a nice thing to do to them, but they are much more tolerant of it.
So, you can use a leisure battery to start your car, but it won't be great at it, and you can use a standard battery as a leisure battery, but the continual 'deep cycle' discharging will shorten its life significantly.
Horses for courses.
Re: BATTERY QUESTION
Posted: Tue Jan 05, 2010 12:56 pm
by missfixit70
francophile1947 wrote:You can use a starter battery as a leisure battery (I have done so), but rumour has it that they don't like being discharged to the extent that a leisure battery gets discharged, so the life will be seriously shortened. Personally I never found it to be a problem
What size - how big is your battery tray?
Apparently, if you fit a larger capacity (Amp/Hr) leisure battery than your starter battery, they will both only charge up to the capacity of the smaller battery - I have an 85Amp/Hr leisure battery, but loads fit 110Amp/Hr.
So what switches off the charging at this point

? If it's running, it's charging isn't it?
Re: BATTERY QUESTION
Posted: Tue Jan 05, 2010 1:22 pm
by francophile1947
missfixit70 wrote:So what switches off the charging at this point

? If it's running, it's charging isn't it?
Absolutely no idea Kirsty

The fact sheet states that the leisure battery shouldn't be bigger than the starter one and there was a thread explaining why, but I can't find it now

If I remember correctly, it's something to do with the full battery "telling" the charging system to cut the power once both batteries are the same, even though the other battery has spare capacity.
Re: BATTERY QUESTION
Posted: Tue Jan 05, 2010 1:25 pm
by haydn callow
Think this may have somthing to do with the alternator "sensing" the condition of the vehicle battery and adjusting it's output accordingly..
e.g. cold start in the morning the alternator can (for a short while) put out 70/80 amps to replace the amps used....as this is done then the amps put out reduces to as little as 5 amps depending on whats switched on.
However at least a small amount would be charging the bigger battery all the time.
Having a proper "split" charging kit fitted should overcome all this.
Re: BATTERY QUESTION
Posted: Tue Jan 05, 2010 1:38 pm
by rita
Re: BATTERY QUESTION
Posted: Tue Jan 05, 2010 1:42 pm
by dave_aber
http://www.amplepower.com/pwrnews/parallel/index.html
First, a parallel system allows more convenient sizes which yields a greater range of systems. For instance, a 100 Ah battery can be placed in parallel with a 200 Ah unit to obtain a total of 300 Ah. Charging proceeds as expected, with each battery receiving its share of the charge current, and each reaching a full charge at the same time. On discharge, each battery supplies current according to its relative capacity, and both batteries maintain the same percent depth of discharge.
My view on this is that as a battery reaches capacity, its internal resistance increases and thus the current drawn from the charger (or alternator) decreases. This action is independent for both batteries. So if one battery is nearly fully charged, and another at (say) half charge, then the full one will draw a small current and the flatter one draw a larger current - currents in different branches of a parallel circuit add up giving the total current drawn from the source.
Re: BATTERY QUESTION
Posted: Tue Jan 05, 2010 1:51 pm
by falcoron
Cheers,
very informative indeed.
So what is the recommended leisure battery to fit the bongo then?
I will only be running lights and maybe a 12v cooler from time to time but mostly will be on hook up at camp sites.
Also can you recommend a hook up socket to fit to the bongo and where's the best spot to mount it?
Thnaks again
Ron
Re: BATTERY QUESTION
Posted: Tue Jan 05, 2010 2:02 pm
by Colin H F
Hi Ron they are a 16 amp blue and white water proof jobby, mine was inserted into the side panel which means cutting a hole I would have prefered it to have been fitted under the rear bumper and not cut holes in the side panel. Colin
Re: BATTERY QUESTION
Posted: Tue Jan 05, 2010 2:06 pm
by mikeonb4c
dave_aber wrote:It's all about the internal structure.
Starting batteries are made of lots of thin plates to give maximum surface area and thus highest CCA for starting. Running these flat is bad for them. Plates become eroded etc.
Leisure batteries have fewer, thicker plates, which give better overall capacity but lower max CCA. These are more tolerant of running right down to flat. Still not a nice thing to do to them, but they are much more tolerant of it.
So, you can use a leisure battery to start your car, but it won't be great at it, and you can use a standard battery as a leisure battery, but the continual 'deep cycle' discharging will shorten its life significantly.
Horses for courses.
Nicely put
The only contribution I can make is its worth getting Ron Miels view as he did some research on this before buying an Elecsol (I think it was) battery that claims to manage starting demands well while being principally intended for use as a leisure battery. This interests me as I came up with a cunning bit of Heath Robinson circuitry that woud allow me to run an electric blanket off a leisure battery. It worked great on test (ran for 2 nights off a 75Ah starter battery) with an old starter battery, but would not work properly with my LB as the circuit included a low voltage cutout which kept cutting in (if you get me

). I reckon it was because the LB would not maintain voltage at the amperage required. Quite possibly though, an Elecsol type would

Re: BATTERY QUESTION
Posted: Tue Jan 05, 2010 2:15 pm
by falcoron
Colin H F wrote:Hi Ron they are a 16 amp blue and white water proof jobby, mine was inserted into the side panel which means cutting a hole I would have prefered it to have been fitted under the rear bumper and not cut holes in the side panel. Colin
Thanks Colin,
Cutting holes in the side holds no fear for me, Im a paint sprayer by trade and have lots of body work experiance. Although i would have prefered not to.
Just wondered if anyone has done it and where the best place would be?
given once you fit it, is it in the best spot and would you have put it in a better spot with hindsight.
Saves me making an error that you guys may have already done and thought " wish i'd put that there"
If you catch my drift.
Re: BATTERY QUESTION
Posted: Tue Jan 05, 2010 2:15 pm
by dave_aber
I've been looking at these ecosol ones too. I have a Willinton kit fitted, but as yet no L/B in place. I'm considering adding a marine battery switch to allow me to start off either Normal, leisure or both batteries should the emergency need arise. Will also allow manual linking of both for charging if the Willinton kit main fuse(s) blow for some reason.
Re: BATTERY QUESTION
Posted: Tue Jan 05, 2010 2:29 pm
by Colin H F
when you go to a site with hook up they are normally at the rear or towards the rear on the side so it makes sense to fit it near the rear .mine is flush with a hinged cover and a realease lever inside. Colin