jonlea
Well-Known Member
Can anyone please advise me what size in CCA starting batteries I need for a Mercruiser 7.3 D Tronic – it is a V6 3 litre diesel engine?
Mercruiser Starting batteries
- Thread starter jonlea
- Start date
jonlea
Well-Known Member
Sorry - I should have V8 not V6
RobWales
Well-Known Member
Was this the motor on ebay last week,its a meaty looking lump!
volvopaul
Well-Known Member
Any of these model batteries are quite sufficient for starting. 643, 644, 655, 647, 648. 643,644 are same dimensions but posts are opposite way round,as are 647,648 which are taller and more capacity in ah and cranking capacity.
Dont bother buying from any chandlers a truck or good lucas type factor is fine.
Dont bother buying from any chandlers a truck or good lucas type factor is fine.
G
gingie
Guest
you will need a minimuim of 300 amp batteries
andyball
Well-Known Member
Elessar
Well-Known Member
I've re engined two boats with diesel and fixed a friends that was supposedly professionally re engined.
Firstly ensure your engine battery does only that, and that your domestic battery does everything else and charges second using an automatic relay.
Then its not the Amp Hour of the battery that really matters it's the cranking current. A halfords car battery for a large diesel will be fine. Or go to a truck factor as already suggested.
The weak link will be your battery cables. Keep them as short as practical. The mercruiser spec sheet details this but that's on the boat (i'm not) just use cable that looks too thick then double it up. Sorry I can't remember the exact details but the battery cable cost me £200 without the ends crimped on so you should get the idea - chances are a re engine or even and original install will try to cut costs.
And it is a 7.3L not 3L you have but I guess that was just a typo?
I hope that helps.
Firstly ensure your engine battery does only that, and that your domestic battery does everything else and charges second using an automatic relay.
Then its not the Amp Hour of the battery that really matters it's the cranking current. A halfords car battery for a large diesel will be fine. Or go to a truck factor as already suggested.
The weak link will be your battery cables. Keep them as short as practical. The mercruiser spec sheet details this but that's on the boat (i'm not) just use cable that looks too thick then double it up. Sorry I can't remember the exact details but the battery cable cost me £200 without the ends crimped on so you should get the idea - chances are a re engine or even and original install will try to cut costs.
And it is a 7.3L not 3L you have but I guess that was just a typo?
I hope that helps.
duncan
Well-Known Member
Jonlea - I think you mean 7.3l rather than 3l if it's a v8........ anyhow on a big diesel I would go for a tgruck battery as our friend from the midlands suggests - 800CCA is going to do the job just fine and, as also already suggested, just make sure your starter cables are in good nick adn well connected to make all that go go juice available safely.