Which battery is best?

[Begester]

I've got a 2022 Sea Ray SDX 270 outboard, both batteries are dead and not holding charge and I'm going to replace them. Curious to hear thoughts on the best way to go about this. I've heard to get one deep cycle and one regular, although I thought all marine batteries are deep cycle so I'm not sure if that's correct. Also considering going with lithium batteries and would love to hear any perspective there as well.

Boat will be stored on a lift in salt water and I've got a trickle charger that I can connect when not using, although I'd prefer to not have it hooked up 24/7.

 

[jimmbo]

No, all Marine Batteries are not Deep Cycle. If you want to run both, Cranking Battery for the Engine, and Deep Cycles for all the Electronics, then a way of Isolating them from each other, with regards to Charging, unless your Outboard, has 2 separate Charging Systems(I know my OMC FICHTs did)
I guess you could connect several Deep Cycles in Parallel, and that would easily provide enough Current for extended Cranking, but you still have the Issue regarding Charging.

Lithium? If one of those Babies ever decides to go Nuclear, you will be treading Water very quickly. Stick with old fashioned Flooded batteries. AGMs? Unless the Charging System is Optimized for them, I wouldn't use them. Cue the "I've been using AGMs forever and they are Great" crowd...

 

[alldodge]

Being a 2022 it will have keep alive power connected and there is a small drain even when Bat switches are turned off. If Bat switches are not turned off there is a bit more power draw

Boat needs to have a charger plugged into shore power

I use Odyssey Bats, there expensive but last

 

[bajaman123]

what is your power consumption profile? In other words, do you have a lot of electronics on board, or a powerful stereo system, or use a trolling motor? This will help determine your battery selection. On my last two boats I have used (2) 'dual purpose' batteries with an isolator switch. I have had great luck with Odyssey AGM recently, but good old basic lead-acid batteries work fine too. I have a really powerful stereo that consumes a lot of power so I use one battery for that system when in use, like when sitting in a cove chilling out. Modern lithium-iron-phosphate batteries are very safe, not likely to have any sort of catastrophic failure like the early "lithium" batteries were known for, weigh half as much but cost two to three times as much.

 

[Donald0039]

I would get AGMs manufactured by East Penn. NAPA and West Marine may be manufactured by East Penn

The plain AGMs will typically work fine as a direct replacement for a flooded battery. It's the spiral wound (Optima) or Odyssey batteries that may need different charging.

 

[Begester]

what is your power consumption profile? In other words, do you have a lot of electronics on board, or a powerful stereo system, or use a trolling motor? This will help determine your battery selection. On my last two boats I have used (2) 'dual purpose' batteries with an isolator switch. I have had great luck with Odyssey AGM recently, but good old basic lead-acid batteries work fine too. I have a really powerful stereo that consumes a lot of power so I use one battery for that system when in use, like when sitting in a cove chilling out. Modern lithium-iron-phosphate batteries are very safe, not likely to have any sort of catastrophic failure like the early "lithium" batteries were known for, weigh half as much but cost two to three times as much.

Good points, I don't have a huge stereo or anything and am pretty good about not going to long without starting the engine to charge the batteries. I almost always run on both

 

[FLATHEAD]

I second the East Penn AGM deep cycle batteries. Have had great results from them. East Penn manufactures batteries for many different brand names. I go to the plant and pick up batteries, never know what brand name you’ll see. Sometimes they have blems at a good discount.

I dipped my toe into the lithium LiFeP04 as of late. This will be my second full season with them, so far so good.

 

[tpenfield]

I've used dual-purpose marine batteries with good success in the past. As for Lithium (specifically LiFePO4 type) . . . not really a nuclear risk, but charging and using them requires a bit of science.

There are some 'drop-in' LiFePO4 batteries available . . . BUT . . . your outboard motor needs to be 'lithium' compatible . . . as it requires a 'smart' alternator for charging. You can probably verify this by referring to the outboard owner's manual, etc.

 

[Pmt133]

What they said. I stick with flooded... they last long enough though AGM can tolerate poor charging habits better.

The LiFePO4 batteries are inherently safe. Have I seen them melt down? Yes. Was it caused by absolute abuse a normal application should never see? Yeah. Would anything else in that situation be a disaster? Yes. My favorite was an array of batteries hooked directly up to a solar panel array... no charge controller, no cooling, no nothing. Just fed directly off them sitting in the middle of the yard on a 90 degree day. The fact only one popped and burned for ~10 minutes is a testament to how safe they actually are.

 

[Begester]

Should I get both batteries as deep cycles? The ones on there now (installed by the dealer) appear to be the same but on previous I/O's I always had a starting and deep cycle battery.

If it matters, engine is a mercury 300 verado V8.

 

[alldodge]

Verado manual states to use AGM only

 

[alldodge]

 

[jimmbo]

As Always, People should check the Owners Manual first. Of course REAL Men NEVER read an Owner/Operator Manual....

 

[JimS123]

Regular flooded deep cycle dual purpose batteries is what I use and would recommend. AGMs are good for a jetski where they get jossled around a lot, but not cost effective for a boat.

Don't use a trickle charger. If you use the boat every week, don't worry about it. Use one battery going out and the other returning. If the boat sits idle for more than a month, use a regular charger monthly.

 

[alldodge]

Regular flooded deep cycle dual purpose batteries is what I use and would recommend. AGMs are good for a jetski where they get jossled around a lot, but not cost effective for a boat.

With all due respect
The Verado was and is designed to be a power hungry machine and requires a higher current delivery system then other 4 stroke motors. On the low side the Alt is 85 amps, the high side is 115 amps

I'm no expert on any outboard, but the OEM does not make Bats and doesn't make anything off someone buying any Bat, so if they say use only AGM ???

Note there are AGM's which are not a lot different then a LA but still better, like Duracell AGM, Mercury/Mercruiser AGM, Optima AGM. True AGM is Odyssey, Lifeline, Trojan

 

[JimS123]

With all due respect
The Verado was and is designed to be a power hungry machine and requires a higher current delivery system then other 4 stroke motors. On the low side the Alt is 85 amps, the high side is 115 amps

I'm no expert on any outboard, but the OEM does not make Bats and doesn't make anything off someone buying any Bat, so if they say use only AGM ???

Note there are AGM's which are not a lot different then a LA but still better, like Duracell AGM, Mercury/Mercruiser AGM, Optima AGM. True AGM is Odyssey, Lifeline, Trojan

I missed the post detailing the AGM requirement. (I DO read owners manuals, but not always every post)

That being the case, you can't go wrong with a Trojan. I have had iffy longevity with Odyssey, but my Trojan is the best battery I ever had.

 

[Donald0039]

AGMs are also stronger and can take pounding of waves better than flooded.

 

[jlh3rd]

to the OP:
I like this guy. Worth a listen. report is 4 years old, and not marine battery, however.
I go well over the 3 year warranties on my everlasts, but I do "maintain " them.
My 2021 Merc outboard,115hp, stated battery requirement was 1000 CA, so I'm headed into my 4th year with that new battery. The "old" battery is now my auxillary battery well into 6+ years. (pontoon, dual battery setup). I do have small solar chargers connected to each, guess they help.