Battery CCA

[absit_omen]

I have a Yanmar 2GM20 and need to replace the starting battery. Unfortunately, the manual does not give the battery rating in CCA. In fact, it does not cover batteries at all!

Can anyone, preferably from personal experience of this engine, advise the minimum rating of battery I should be looking for.

Many thanks

 

[BAtoo]

Volvo 2003, 28hp; I use a either 110AH dual purpose or a RedFlash AGM type, 17AH (IIRR) but loads of CCA (V small - 1/3rd shoebox size - lighter; mount in any position; bit pricey tho.

 

[philip_stevens]

When I enquired about a starting battery for my (previous boat) Bukh DV20, I was told that the minimum size was 65Ah for a "proper" starting battery - not a leisure battery.

 

[tom52]

I believe the minimum CCA for the volvo 2020 (19HP) is 450CCA.
(I do not think Ah are the relevent measure for a starting battery.)

 

[steve28]

same engine and i use a 110amp hour dual purpose lucas squadron energy2 cost was about 50 pounds, same battery for the domestics.

 

[MrCramp]

I had same question 7 years ago when I bought a boat with tthe same engine. I don't know where I got the answer from and I have just tried the Yanmar help forum but it is still down.

We have 3 Peugeot 306s which have 1900cc turbo diesel engines which are roughly twice the size of the Yanmar which is around 900cc. I ended up with a spare car battery and used that for 6 years on the yanmar and it was still going strong when I sold the boat.

The Peugeots have a 495cca battery. I now have a Yanmar 15qsm(or some similar letters) and will use a similar size battery. I would think that you could go down to around 450cca but there are loads of these engines about and I would expect someone else to come along shortly to give their view.

I also had 2 110ah domestic batteries which could start the engine if necessary. I am a belt and braces man when it comes to going to sea and I will always have a dedicated engine starter battery.

 

[philip_stevens]

I've just looked at the technical specs for our VP2003 and it gives the battery size as 70Ah.

So, the DV20 at 65Ah, and the VP2003 (28hp) at 70Ah.

 

[jimbaerselman]

As the OP recognised, for starting purposes, AH is not necessarily relevant. What matters is the ability of the battery to deliver current - Cold Cranking Amps (CCA) - something different.

Car abtteries are generally designed to start engines; their CCA are high compared to their AH capacity. Deep cycle batteries may have very high AH, but relatively low CCA - they have less surface area within the cells, but are very much more robust.

For my four cylinder Perkins 4,108 a 750 CCA was recommended for starting, with no AH specification. In the warm weather of the Mediterranean, I got away with a 650 CCA battery (battery delivers more in warm conditions, and oil friction is lower).

The main factors affecting choice of CCA are cylinder size and compression, the inertia of the rotating masses within the engine, the number of cylinders, and the lowest temperatures you're going to try and start up. Diesels, with higher compressions than spark ignition engines for the same cylinder size, are more demanding. So don't look at comparative petrol engine starter batteries.

No, I can't answer the OP's question!

 

[William_H]

You will probably find that a car battery is cheaper and you should choose one that is comparable physical size to what you have. Or ere on the larger size if it will fit. As stated car batteries especially for diesels are designed for high CCA./ olewill

 

[absit_omen]

Many thanks everybody.

I think I know what to look for now. I must say that this Red Flash jobbie sounds the business as it is used to start jet engines. Pity I can't afford one!