View Poll Results: 24' center console - 2x dual purpose vs 1 cycle/1 starting
2 dual purpose




7
33.33%
1 deep cycle + 1 starting




8
38.10%
2 starting




1
4.76%
2 deep cycle




5
23.81%
Voters: 21. You may not vote on this poll
2 Dual Purpose Batteries vs 1 starting/1 deep cycle
#1

Are dual purpose batteries any good or jack of all trades, master of none? I have a 2 battery setup in my 24' center console. Right now they are both starting/cranking batteries but I am looking to swap them out. I had planned to get one deep cycle and one starting battery. Dual purpose batteries seem interesting and if I had 1 battery, I think it would be a no brainer but with 2 is it better to go with 2 dual purpose or one deep/one starting?
For additional discussion, AGM vs acid?
For additional discussion, AGM vs acid?
Last edited by merlin2375; 10-06-2020 at 07:40 AM.
#3

Hi Drako - my current batteries are both group size 24, I was going to replace them with 24s again. Are you saying that you had to go with a larger battery to get what you needed in terms of CCA?
#4
Senior Member

Yes. Look up what your outboard specifies for CCA and then check what your battery can provide -- it's not just the group size, compare the specs for MCA/CCA. Deep cycle batteries typically have less CCA than similar cranking batteries.
#5
#7

How were the group 24s treating you?
Do you plan on adding more house loads in the near future?
How are the batteries being charged?
without knowing anymore specifics of your vessel, and if she was mine, I would:
grp 27 start and grp 27 deep cycle.
and AGM is a type of lead acid battery. You have three types of lead acid: Flooded, AGM, Gel.
they all have their pros and cons.
Do you plan on adding more house loads in the near future?
How are the batteries being charged?
without knowing anymore specifics of your vessel, and if she was mine, I would:
grp 27 start and grp 27 deep cycle.
and AGM is a type of lead acid battery. You have three types of lead acid: Flooded, AGM, Gel.
they all have their pros and cons.
#8
Senior Member

#9
Senior Member


oops
Last edited by coores14; 10-06-2020 at 01:22 PM. Reason: double post
#10
Senior Member


oops
Last edited by coores14; 10-06-2020 at 01:22 PM. Reason: triple post! dang you THT!
#11

Thanks for the replies. Good points.
1) I will have to change out the batt trays to go from 24 to 27 group size, not a huge problem but would have to do so.
2) When one has two batteries, is there anything that says the two batteries have to be exactly the same?
3) Seems like most AGM batts are dual purpose not starting vs deep cycle? Am I missing something?
1) I will have to change out the batt trays to go from 24 to 27 group size, not a huge problem but would have to do so.
2) When one has two batteries, is there anything that says the two batteries have to be exactly the same?
3) Seems like most AGM batts are dual purpose not starting vs deep cycle? Am I missing something?
#12
Senior Member

I would use 2 Group 27 dual purpose. That's what I have on my 20' w/Yam 150. I've always been told the batteries should be the same or you'll throw off the charging system. Not sure how much fact was behind it, but it came from a supposed "battery guy". The reason why a lot of the AGM are Dual is, for the most part, you want to have a "back up" for starting and the standard Deep Cycle won't do it. In my double setup, my normal routine is to run #1 on the Saturday and #2 on Sunday. If I sit with the engine off for more than an hour and something running, then I'll put my switch in "both" if she tries to drag a little at startup, but rarely do I need to. This routine has worked pretty well for me and keeps both batteries in-use and sufficiently charged. Of course, I'm a stickler for charging at home the night before too.
#14

Thanks for the replies. Good points.
1) I will have to change out the batt trays to go from 24 to 27 group size, not a huge problem but would have to do so.
2) When one has two batteries, is there anything that says the two batteries have to be exactly the same?
3) Seems like most AGM batts are dual purpose not starting vs deep cycle? Am I missing something?
1) I will have to change out the batt trays to go from 24 to 27 group size, not a huge problem but would have to do so.
2) When one has two batteries, is there anything that says the two batteries have to be exactly the same?
3) Seems like most AGM batts are dual purpose not starting vs deep cycle? Am I missing something?
two of the same exact AGM 27s (labeled deep cycle or dual purpose)will be A ok to use on your boat. Just make sure they meet minimum CCA.
Last edited by Onebadlarry; 10-07-2020 at 10:28 AM.
#15
Senior Member



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Thanks for the replies. Good points.
1) I will have to change out the batt trays to go from 24 to 27 group size, not a huge problem but would have to do so.
2) When one has two batteries, is there anything that says the two batteries have to be exactly the same?
3) Seems like most AGM batts are dual purpose not starting vs deep cycle? Am I missing something?
1) I will have to change out the batt trays to go from 24 to 27 group size, not a huge problem but would have to do so.
2) When one has two batteries, is there anything that says the two batteries have to be exactly the same?
3) Seems like most AGM batts are dual purpose not starting vs deep cycle? Am I missing something?
#16
Senior Member

Run 2 group 24 deep cycle batteries. Interstate/Costco wet cell batteries lasted me 9 years. They were still cranking well when it seemed prudent to buy new ones.
They start my DF300ap without issue.
They start my DF300ap without issue.