Marina 75 battery

[Neal]

Had a problem with battery yesterday it is only just over a year old 80Ahr. It was not flat (PTT still moved etc) but would turn over the engine Marina 75, does anyone know if that size battery is good enough for long term use on this engine. When i had the previous starting problem I noticed it did give up a bit quick then. There is very little other power used on the boat.
Managed to top up from the car to get going. The battery spends long periods of its life on a top up charger when not in use. The cells acid level were fine this morning.
Many thanks.

[Neal]

Bit more information thanks to the nice man at Barrus the CCA is 350A on the engine 80 Ahr should do but they think 105 would be better.

[codprawn]

I had serious problems starting my boat the other day. It was spinning over okayish but not as it should - just wouldn't start. Put another battery on with jump leads - still no joy - jump leads got very hot. Took the old battery out and connected the new one - started 1st turn of the key!!!

[jwalker]

Originally Posted by Neal

... 80 Ahr should do but they think 105 would be better.

Pish. Neal, you've obviously got a problem and a replacement battery may solve it but 105ah is just unnecessary. I use a 90ah battery to start my Volvo diesel and that is plenty. I used to use 48ah to start my 200hp outboards.

Big cables and good connections.

[Hugh Jardon]

we use a pair of 120a ones as the opti takes a turn to start and the comfort of a second is good.

however it does sound like you may have a problem drawing more than you are putting in, do you know what voltage the battery is reading when the engine is running, need to be sure it is charging sufficiently

[Neal]

Originally Posted by jwalker

Big cables and good connections.

Thanks JW while you were on line I have been pulling the electrical connections appart and big cables or the lack of them in one section could be the problem, link to the battery switch was done in what looked like 6mm2 cable I could only see this when I got the fuseboard out. Going to try and replace tonight. There was a post about battery cables week or so back so off to search for that.

Dont think i have room for a second battery but will look into that for winter project. Does any one know what voltage will show correct charging with the engine running so i can check that.

Thanks all

[Mrs Jardon]

on a car it is 13.7 to around 14.2 or maybe a little higher/lower when running, not sure on a boat but must be similar i would expect

on our boat cos the batteries are in the console we got some cables made up which are quite long but are absolutely huge, a real bugger to route thru the trunking etc but we know they will carry the amps which is what is importatnt

second battery is a must as if the first ran down due to leaving something on or the engine was not charging properly we know we have a fall back of the second

cheers

chris

[jwalker]

Originally Posted by Mrs Jardon

..on a car it is 13.7 to around 14.2 or ...second battery is a must as if the first ran down due to leaving something on or the engine was not charging properly we know we have a fall back of the second.

Agreed.