Binman
Well-Known Member
I understand the CCA batteries give you a cranking power from 0 degree, where as the MF battery gives it from 32 degrees, are they both as good as I another, my battery needs replacing it is a 105 hr cca860 12v
Marine batteries, MF or CCA
- Thread starter Binman
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macd
Well-Known Member
CCA...cold cranking amps...are measured at 0 degrees F. That's why they're called 'cold'. If they're not measured at 0F, they're not CCA.
There is such a thing as CA...cranking amps...which are measured at 32 degrees F. Because lead-acid batteries at 32F produce more power than at 0F, you would expect the CA figure for a battery to be higher than the CCA figure for the same battery. In other words, a CCA figure of say, 860, is 'better' than a CA figure of 860.
If it's a starter battery you're seeking, you'd be best advised to choose one marked with a CCA. Your engine manual should tell you the CCA figure (and possibly also the Ah figure) that you require.
For what it's worth, there's also HCA...hot cranking amps...a test conducted at 80F, which happens to be roughly where lead-acid batteries are most productive. All three tests are identical save for the temperature at which they're conducted: the number of amps a battery can deliver for 30 seconds before the voltage drops below 1.2V per cell.
As you might infer from the units, these tests are US-orientated, although CCA has become universal. I've never seen (or never noticed) a battery with CA or HCA figures, even though my domestic batteries are from a US company.
There is such a thing as CA...cranking amps...which are measured at 32 degrees F. Because lead-acid batteries at 32F produce more power than at 0F, you would expect the CA figure for a battery to be higher than the CCA figure for the same battery. In other words, a CCA figure of say, 860, is 'better' than a CA figure of 860.
If it's a starter battery you're seeking, you'd be best advised to choose one marked with a CCA. Your engine manual should tell you the CCA figure (and possibly also the Ah figure) that you require.
For what it's worth, there's also HCA...hot cranking amps...a test conducted at 80F, which happens to be roughly where lead-acid batteries are most productive. All three tests are identical save for the temperature at which they're conducted: the number of amps a battery can deliver for 30 seconds before the voltage drops below 1.2V per cell.
As you might infer from the units, these tests are US-orientated, although CCA has become universal. I've never seen (or never noticed) a battery with CA or HCA figures, even though my domestic batteries are from a US company.
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theoldsalt
Well-Known Member
No such thing as a marine battery. Buy a "car" battery with the appropriate CCA and Ah. I get mine from http://www.batterymegastore.co.uk/ excellent price, service & delivery.
eg http://www.batterymegastore.co.uk/product/H3/
This informative video may help.
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VicS
Well-Known Member
I think you will find that the rating at 32F is often called MCA ( Marine cranking amps)
I have not come across MF before.
You will find a conversion factor on line but AFAIK its only a rough conversion , not a precise one.
A 105Ah, 880 CCA battery is able to supply a high enough starting current to start a pretty substantial engine a good few times. It's far larger than you need for small yacht engines.
The advantage of a large Ah capacity is that you have bags of power available for all your power hungry bits of kit but the disadvantages are the high replacement costs, the physical size and the weight
I now usually buy batteries from Tayna. Good prices and unbeatable service, although much to be said in favour of Halfords for convenience
I have not come across MF before.
You will find a conversion factor on line but AFAIK its only a rough conversion , not a precise one.
A 105Ah, 880 CCA battery is able to supply a high enough starting current to start a pretty substantial engine a good few times. It's far larger than you need for small yacht engines.
The advantage of a large Ah capacity is that you have bags of power available for all your power hungry bits of kit but the disadvantages are the high replacement costs, the physical size and the weight
I now usually buy batteries from Tayna. Good prices and unbeatable service, although much to be said in favour of Halfords for convenience
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Tranona
Well-Known Member
I seem to remember you have an outboard engine so CCA is irrelevant for you - only important if you are using it as an a engine start battery for a diesel. Equally as you have no high charging or high consumption it is the capacity you look at and any battery that will fit the space will do. The larger the better as it will extend the time between charges.
VicS
Well-Known Member
Not if you have to lift the fecking thing into a fragile dinghy to take it ashore for recharging. It's only since fitting a solar panel that I have moved up from the smallest Leisure battery I could find.
If you genuinely need the capacity break it into a bank of two smaller batteries, or 2 x 6 volt batteries
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macd
Well-Known Member
Yes, CA and MCA are the same...perhaps because if it gets to 0F at sea, you'd rather be somewhere warmer, like the aft deck of the Scharnhorst.
No idea about MF either.
P.S. You won't need this pointing out, Vic, but others might: even if a battery has an 'MCA' rating, that doesn't make it a marine battery. It just means it's been tested at 32F.
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Binman
Well-Known Member
My mistake, MCA I ment not MF, loosing my marbles, The engine I took out was a 9.9hp Yamaha electric start, high thrust prop, I put in a 2014 5hp Honda with a charging lead, now I have usual VHF/D.SC., An auto pilot, SH Chart plotter, lights, a normal radio, electric bilge pump,Nav lights, cig charger,might need to charge Tablet and IPad, that's it, now there might be a time that I put back the Yamaha, say I intend to cross channel or do a Thames or East coast trip, what size would you recommend? Lifting the existing battery out wasn't a problem, was heavy. It sits under the step into the cabin,easy excess able, just lift step lid up,then lift out.
VicS
Well-Known Member
Mine is a marine battery !
700MCA and even got a picture of a yot on it!
macd
Well-Known Member
Mine is a marine battery !
700MCA and even got a picture of a yot on it!
I've seen Hella electric fans for sale, with a picture of a yot on the box.
Identical fans (at around half the price), bear a picture of a lorry.
Could it be that pictures are cheaper than marinising...
KellysEye
Well-Known Member
CCA for engine start deep cycle battery, such as Trojan, often 6v wired in series, for house battery.
RichardS
N/A
macd
Well-Known Member
Yes, but you have to allow for KE's lack of punctuation. I think that's what he meant.
Incidentally, Trojan state that their deep-cycle jobs are perfectly OK for engine starting. After all, just because a battery can deliver 860A for 30 seconds doesn't mean you actually need it. It'd fry the wiring on most boats.
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RichardS
N/A
theoldsalt
Well-Known Member
Many of us have only ever fitted deep cycle (domestic) batteries on our boats as they are capable of providing cranking current sufficient to start the average yacht diesel. However engine start batteries are not suitable for deep cycling and their life will be seriously shortened if used that way.