Battery replacement

[Bloggsy]

Time to replace the 2 boat batteries. I have a voltage sensitive relay fitted so the starting battery is always charged first and then the accessories battery gets charged therefore you don't have to worry about having a position 1-2 1&2 changeover switch. And I run all my accessories off the second battery. My questions are what would be the most suitable batteries to purchase. I have been told that a deep cycle battery for the accessories would be best but I was of the belief that deep cycle batteries don't like being fast charged as the outboard alternator would do. Also it would be easier to be able to charge both batteries with the one charger as I have a ctek port dash mounted. I currently have 2x Century Marine Pro 680 fitted which came with the boat but in previous boats I have always used Supercharge Sea Master batteries MFM50 I am restricted for room so cannot go any longer that 170mm max. I am running a single DF175apx

[Moonlighter]

You must mean 270mm max length?! Lol!

I like the Seamaster g o l d maintenance free. Both for start and house.

Got 9 years out of my last pair and they were still going! Replaced them just out of caution before a trip up north.

I just swap them over every few years so the work gets shared around.

Maintain mine with a little ctek charger too.

Just check that the MFM50 meets the CCA requirements for your engine, should be stated in your owners manual.

[Moonlighter]

Another great option is the Supercharge Allrounder.

It has great starting CCA plus greater reserve capacity so the best of both worlds from starting and deep cycle.

https://www.supercharge.com.au/4wd-b...llrounder-4wd/

[Bloggsy]

Oops yes 270 mm my mistake!

[jaybeekay2]

Have a look at the BLUE top range from Optima not cheap but they really are the best in my opinion

The Blue Top battery is a combination starter and deep cycle battery specially adapted for the marine environment.

https://optimabatteries.co.uk/conten...tima-batteries

[Bloggsy]

Interesting quote from Suzuki page on batteries "Caution: Avoid using deep cycle battery, maintenance-free battery, lithium battery or gel cell battery"

[Moonlighter]

Interesting quote from Suzuki page on batteries "Caution: Avoid using deep cycle battery, maintenance-free battery, lithium battery or gel cell battery"

There’s another recent thread on that issue. The conclusion seems to be that any potential issue might be with the battery rather than with the engine.

Personal experience:

10 years with Seamaster G O L D Maintenance Free. No issues at all. Batteries bought from local outboard dealer!

: edit - this forum has always had issues for some unknown bizarre reason with that word G O L D.