Boat battery.

[Hardyakka]

I'm looking to getting my boat up and running and need a new battery for my boat. When I bought it it was fitted with a motorbike battery which did the job but not for long.
I'm wondering how you work out what size battery to get? I have a 40hp Mercury 2 stroke 99 model with electric start. I run a sounder, lights and marine radio (which rarely gets turned on)

[SteveoTheTiger]

A quick search of the old interweb and i found this chart...

EVINRUDE
Outboard 25 - 90 hp = 640 - 800 CCA
Outboard 25 - 90 hp = (Extreme Apps)800 - 1000 CCA
Outboard 115 - 250 hp = 675 - 845 CCA
Outboard 115 - 250 hp = (Extreme Apps) 800 - 1000 CCA
extreme apps being very cold temps


Mercury
2-Stroke 6-15, 20/25, 30/40, 40/50 & 60 hp 350- 465 CCA
2-Stroke 75 - 125 hp 450 -525 CCA
4-Stroke 9.9/15 & 25 hp 350- 465 CCA
4-Stroke 30/40, 45/50 hp 350-465 CCA
4-Stroke 30/40, 45/50 hp (Extreme Apps) 750 -1000 CCA
4-Stroke 75/90 350 465 CCA
4-Stroke 75/90 (Extreme Apps) 750 -1000 CCA
V-6 Carb EFI 135/200 & 200/250 hp 490 630 CCA
OptiMax 2.5L/3.0L 750 - 1000 CCA
Verado 135-200hp 800 - 1000 CCA
Verado 200-300hp 800 - 1000 CCA

Suzuki
4-Stroke 25 hp and below 330 - 450 CCA
4-Stroke 40 - 140 hp 512 - 650 CCA
4-Stroke 150 - 250 hp 670 - 850 CCA
4-Stroke 300 hp 800 - 1000 CCA

Yamaha
2-Stroke 50 hp and below 245 -323 CCA
2-Stroke 60 - 150 hp Carbureted 380- 502 CCA
2-Stroke 2.6L 150 - 200 hp EFI 380 -502 CCA
2-Stroke 3.1L 200 - 250 hp EFI 512- 675 CCA
2-Stroke150 - 300 hp HPDI 512 -675 CCA
4-Stroke F25 and below 245 -323 CCA
4-Stroke F30 - F115 380 - 502 CCA
4-Stroke F150 - F250 512- 675 CCA
4-Stroke F350 750 -950 CCA

You might want to look at something like this
http://www.exidebatteries.com.au/batter ... ose/MSDP22

https://www.beaurepaires.com.au/batteri ... y-my-50311

[sandef]

Spend a few extra dollars and also get a charger that has float charge it will add extra life to your battery. Exide dual purpose are good

[SteveoTheTiger]

As a side question...

I have a 75hp Mariner 2 stroke (same as a Mercury 75) and i am currently running a 580CCA battery. It is a single battery setup which also runs an Elite Ti2 7 inch unit and nav lights (not LED). I have never really had any problems starting, but there was one time when the motor took a bit to get going for some reason and i noticed on the last attempt it started to chug a bit but thankfully it then started.

Would i get any benefit from a larger capacity battery. For example a 680CCA?

[sandef]

As a side question...

I have a 75hp Mariner 2 stroke (same as a Mercury 75) and i am currently running a 580CCA battery. It is a single battery setup which also runs an Elite Ti2 7 inch unit and nav lights (not LED). I have never really had any problems starting, but there was one time when the motor took a bit to get going for some reason and i noticed on the last attempt it started to chug a bit but thankfully it then started.

Would i get any benefit from a larger capacity battery. For example a 680CCA?

Go extra exide msdp27 only few dollars more but have it on float to get better life mine is now 3 yrs old

[Nude up]

I have dual batteries in mine and just replaced both batteries with century marine pro 780’s probably way over kill for your application but they do make smaller ones. My only advice is make sure you buy one designed for use in a boat they do last longer.
Century marine pro 580 would do the job maintenance free shop around price anywhere from $160 to $220

[Kennyboy]

One battery for motor, one (agm) for electronics, less chance of running motor battery flat