Batteries On 320DA – Please Help to choose the right one

[Alex F]

This is the first season for me on getting (new to me) 320DA. I need to replace one battery, but the simple thing as this looks to be more difficult than just a replacement.

My first puzzle is that I can’t find information how the batteries are setup. I’m looking at the manual and the only information I can see is Port bat 1, Strb bat 1, Port Bat 2, Strb Bat 2 (optional with bow thruster). I can’t see anywhere diagram on how the batteries are used (which is for engine, generator, house bat.).

The second puzzle is, in the manual it says that recommended batteries are:
Group 31, Volts 12, CCA 800, Reserve 200, Quantity 4.
Douglas battery type: 31DCM, item #: 989 or equivalent.

When I purchased the boat (right before last winter) it had all 4 batteries with following parameters:
Interstate Marine/RV cranking

Group 27M-XHD, CCA 800, Marine CA 1000, reserve 180.

By looking at manual’s recommendation I think that either dealer sold the boat with smaller batteries or the previous owner replaced them with cheaper versions. However, this is unlikely, because the batteries look like about 2-3+ years old and the boat is 2004. there’re no stickers indicating the production date.

I guess I’m looking at two options:

Option 1.
Could be the easiest thing to do is to purchase the same battery as the ones I have on the boat now. The only thing is that our local Interstate bat. Supplier has only Deep Cycle ones. This looks like the one that could work well as a house battery, but like I’ve mentioned above, I don’t know which one is wired to be a house battery.

Option 2.
Should I follow the manual and start slowly migrate to correct size by buying Group 31 this time and from now on get only group 31?

Based on my research on the CSR and the web I was thinking to have deep cycle bat as a house battery and cranking for engines and genset.

Any advice would be greatly appreciated.

Thanks,
Alex.

 

[barryg]

Hi Alex,

I just replaced one of the batteries on my 2005 320 as it wasn't holding the charge as well as the others (they are all the originals from 2005) ..They are all Group 27 Deep Cycle (none are cranking). Got the same Interstate Deep Cycle and have never had a problem. Since they are ganged together, you don't need a separate cranking battery; and the deep cycle will allow for the running of the refrig, tv and other appliances or lights and take the constant charging from the battery charger.

Of course you can also go with the Optima type of batteries if you want to.

Barry

 

[Alex F]

Thanks Barry,
As you can see from my post I was looking at group 27 as my first opiton. The only issue I have is identifying it which spot to place it, so it's used as a house battery. From the manual, I can't understand which battery is the house batttery. Do you know which slot is for the house battery?

BTW, dodn't you think that this is strange that manual says that the boat should have group 31, but dealer installed group 27? Based on the batteries on your boat I think that mine came with those 27s from dealer. What's the deal, are they saving $200 on a $230K boat?

Thanks,
Alex.

 

[280 SeaRay]

Alex if you were interested in the Optima's they have a group 31 D31M

I replaced the batteries (group 27) installed by the dealer with 3 D31M batteries. I cannot say enough positive things. They allow us to run our "stuff" on the hook for a couple of days without issues... recharge quickly.... and if you don't care about that stuff.... they have completely eliminated my battery maint requirements. No turkey baster and distilled water jug.... no smells, no mess.

 

[Alex F]

Jeremy,
Thanks for the info. Can you share a good source where I can get those. What did you pay for them?

Thx,
Alex.

 

[rondds]

alex
SR has wacky ways of setting up batteries. i have three batteries. the "port" (single) battery starts the genny and the port engine. it is an everstart marine starting battery. the "stbd" bank (two batteries in parallel) handle house duties and starting of the stbd engine. i replaced the two stbd batteries in the spring of '06 with stowaway group 31 deep cycle batteries from sam's club (walmart) for $69 each and they are great. consumer reports states there are probably only about 4 manuractures of lead-acid batteries out there - they are just re-badged by the retailers and sold for different prices depending upon the brand.

some will tell you you cant start an engine with deep cycle batteries but that is propwash. as a matter of fact, this winter i left a tiny little battery that i took out of my 2001 subaru outback in the boat (connected to the starboard bank). i plugged the boat into shore power maybe 4x over the winter, and thus charged this 6+ year old automotive battery for a total of about 5 hours. yesterday, for kicks and giggles, i started the starboard engine with this mickey mouse battery after charging it for about 2 hours, then used the emergency start button to start the port engine as well (i hadnt put the port battery in yet). for argument's sake it should be noted that i turned OFF the converter when i was cranking the engines up.

so, as i've stated in other posts, i dont see the purpose of spending $200+ for AGMs unless you are a hard-core gunkholer, sleeping around the bay on the hook, with your fridge, anchor and interior lights, ac/dc TV and stereo running allnight long. go to sam's club in freehold and get yourself a couple of group 31s for a song and enjoy them for 3-4 seasons - then use the money you save to buy GASAHOL and beer!

also of note: walmart doesnt sell the group 31s. they DO sell group 27 deep cycle batteries, i believe, for about the same price as the 31s in Sam's Club.

 

[Alex F]

Thanks Ron,
I don't like to spend more than it's necessary. This is a good option to explore. I also tink it better to spend $100 for one battery and replace it after 3-4 years, than pay $200 and hope for it to work for 6+ years.

Thanks again,
Alex.

 

[skolbe]

How did you guys test which one that is bad - voltmeter?

 

[Alex F]

Skolbe,
This battery was missing both caps. When I had the shore power plugged in all batteries were chargine. When I took all of them out for the winter this battery was reading about 8v or less. I don't know how long this battery was in the the boat in such condition. But, one thing I know that it's not worth of messing with it. It's a new boat to me and I want all components to be reliable. So, I didn't even take it home, but just left it near garbage container next to other junk.

Alex.