Are AGM and Flooded/Wet Cell Batteries Interchangeable

[Windjammer]

Well, it is time for a battery change on the '06 340 Sundancer, and no complaints - got 7 years out of the last ones. When I changed out the originals I just took one from the boat with me and went to Interstate and said "I need 4, just like this one", and this turned out to be their 27M-XMD.
Checked the Owners Manual and it says the Recommended is Group 31; CCA:800, Reserve:200. So am thinking of upgrading from Group 27's to Group 31's. Mostly what I have found is that Group 31's are AGM instead of Flooded/wet cell.
Just wondering if my Charger will notice any difference or if I need to change the setting? I don't know what charger I have and it looks like a pain to get to - I can see it through the little window in the "cave". Or just go back with Group 27's?

 

[WV 320 Dancer]

Are you going to do all 4 if so Sam’s has a fantastic price on AGM’s.

 

[Windjammer]

Are you going to do all 4 if so Sam’s has a fantastic price on AGM’s.

Planning in all 4. I figure if one fails, the rest aren't far behind.

 

[MonacoMike]

Batteries should always be changed in the groups that connect to one another.

MM

 

[carterchapman]

David - you can get 31's wet or AGM. the Sam's deal ROCKs for the Duracell AGMs! They were $184, someone posted they are down to $140...

I have never changed settings on any charger and I've put AGMs in place on 3 different boats. GEL batteries require different settings and probably a new charger - not AGMs...

 

[Wylie_Tunes]

Interchangeable as in can they be used for the same application? Absolutely. Choose one in the same manor. Group size, CCA, RC and Ah. The only real consideration, is if there is an on-board charger, can it safely handle an AGM profile.

Interstate sells a group-29. Pretty much a 31 under others brands.

 

[Todd320]

I have an 07 320, and I put AGMs in Dec 2017 (upgraded from 27s as well, which had been replaced in 2015). So far, amazing. Everything works better, bow thruster responds immediately, engines crank great, run both fridges all day, and GPS/depth finder all day, VHF, both radios, one to play music, one as an iPad/iPhone charger, all day, and most importantly, no low power warning beeps from the CO sensors. I have an intellipower PD2030 charger. Leave for 2 or 3 weeks, come back, all good.

 

[bbwhitejr]

Sam’s has great prices on Group 31 wet cells. I had a bank of 2 for house batteries in a previous boat and loved them. Like you, I get 6-7 years out of wet cells and thus far, have not justified the price difference. Current boat has all batteries set up in a cluster, very easy to get to and have required very little water every 6 months. Cranking batteries are going on 5 years old.

Bennett

 

[M Prod]

Switched all 4 of mine from group 27 wet to group 31 AGM's last season. Extremely happy with them. As others have said, definite uptick in performance and didn't need to change anything charger wise.

 

[bobeast]

You can replace all 4 with AGMs and your charger will still work fine.

BUT

A more modern charger will take better care of your AGMs by providing a charge profile specific to their chemistry. translated: they'll probably last longer with a better charger.

 

[techmitch]

S

You can replace all 4 with AGMs and your charger will still work fine.

BUT

A more modern charger will take better care of your AGMs by providing a charge profile specific to their chemistry. translated: they'll probably last longer with a better charger.

+1, Battery and charger technology has come a long way since the OP'S boat was built so this would be a great time to update/upgrade the batteries and Gen/Shore power charging system.