Battery for Mariner Optimax 135

trellis · 10 March 2006, 15:44

Hi,

I've read a lot of stuff on this site about marine batteries, but still not exactly sure about what I need to buy.

We've got a Mariner Optimax 135 engine on our rib (we've just got this fitted to it). Previously we've had a cheapy Halfords 75Ah lesuire battery in it... (only powering a smaller tohatsu engine) suffice to say it doesn't start the new engine.

In the manual it says it requires 1000MCA or 800 Cold cranking amps... this seems like quite a lot to me!!

What are the recommended batteries to provide this?

I've spoken to a few yards and one thinks something different to the other, on one hand a 85Ah battery was recommended and another shop said we'd have to have 2 x 85Ah batteries.

Can anyone shed some light?

Cookee · 10 March 2006, 15:57

Go with the manual - it's because the ECU needs a constant voltage and if the battery isn't man enough, when you hit the trim it will drop the voltage below the threshold and cause problems with the ECU - We use Optima batteries - they aren't cheap but they are very good!

Ribshop · 10 March 2006, 15:57

Optimax do like a bigger battery than a standard motor, we usually fit 1 x 120ah battery. but Optima batteries are very good.

Hugh Jardon · 10 March 2006, 16:01

due to the way optis start they do need powerful batteries as they do almost a full rotation before firing, on my 200 opti i have fitted twin 120 ah batteries, these were around 70 quid each and the batter selection switch from blue sea is about 20 quid

i would go for slightly more powerful batteries than less so you might be fine with 100 amp batteries which could be around 50-55 quid

the make of mine are squadron marine batteries with double poles from ron hale marine

trellis · 10 March 2006, 16:08

Interesting.... I'll take a look at the 100+ Ah batteries then... Are they a lot bigger than the others? Just thinking of the area it has to fit in...

le_forban29 · 10 March 2006, 16:24

They're about 50% longer. I have a 105A for my TLDI, 100 recommended, 120 for cold climates, much more than what was recommended for carbed Tohatsus.

CJL · 11 March 2006, 00:00

I've got twin 85amp/hr on mine.

Starts on one battery no problems.

Chris

Jeff · 11 March 2006, 08:55

I bought a Halfords calcium, compact but :

Battery 110 AH , 620 CCA 4 year warranty ..... at £76

Turbodiesel · 11 March 2006, 20:37

Optima Batteries are the way forward, as they are quite small in size, Fit what the book says, I cant remember off hand what a 135 should need. But it will give you three different figures either amps or CCA, as long as the battery meets one of those requirements you will be fine.
Opti's need lots of battery power as they can take upto two or three turns to charge the air system to get it running.