Cranking battery for Mercury 115 Pro XS?

[CaptainB]

Hello, I have 3 batteries (2 trolling and 1 cranking) that are around 2.5 years old.  They are all leaking a little which caused the straps on the trolling motor batteries to break.  I don't want to deal with leaking batteries any more so I'm going to replace them with AGM batteries (I looked at lithium batteries but they are out of my price range).   My engine calls for 800 CCA or 65 Ah.  Most of the group 24 AGM batteries I have looked at have well under 800 CCA but more than 65 Ah.  I found a few AGM batteries that have more than 800 CCAs but they are $100 more.

 

My question is are any of you running your Mercury 115 4 stroke on a battery with less than 800 CCA but more than 65 Ah and if so is it starting just as quickly as before or have you had issues?  I fish a lot by myself far away from the boat ramp and my cranking battery also runs my sonar, nav lights and pumps so I'm leaning towards spending the extra $100 over the regular AGM batteries to cover both the CCA and Ah requirements.

 

Thanks,

Bryan

[jbsoonerfan]

I use this one with a Merc 150 running 2 Helix 8's, Mega 360 and all my other accessories. It will last all day. 

 

https://www.academy.com/shop/pdp/interstate-batteries-deep-cycle-group-29-840-marine-cranking-amp-battery#repChildCatid=6440505

[K1500]

Throw some jumper cables in and you can always jump your main motor from one of the trolling motor batteries. 

[Jig Man]

Your engine specs are for minimum cca.  Get a bigger cranking battery, group 29 or 31 if they will fit.  

[GaryH]

Never go under the minimum cca that extra $100 is well worth the piece of mind.

[Way2slow]

Just throw some jumper cables in it!!!

You have to love that mentality.  Doesn't matter that a weak/bad battery can destroy a charging system and the arc you sometimes get connecting jumper cables can destroy the ECM.  You can buy a number of batteries for the repair of either of those are going to cost. 

[Angry John]

14 minutes ago, Way2slow said:

Just throw some jumper cables in it!!!

You have to love that mentality.  Doesn't matter that a weak/bad battery can destroy a charging system and the arc you sometimes get connecting jumper cables can destroy the ECM.  You can buy a number of batteries for the repair of either of those are going to cost. 

As a repair an maintenance plan I agree, it's not really a plan at all or at least a destructive one.  As a just in case dont want to be stranded contingency I can see a lot of value.  Your running a three battery setup so I'll just assume that it's a bigger boat.  Never meet a guy with to much battery capacity.  The current cost of Li is to high for me but they were going lower.  If there is anything about going green that might be good would be lowering battery costs.  If you have any technical ability building a battery pack may be cheaper and better.  Tons of YouTube videos of people doing it.

[BigAngus752]

12 hours ago, jbsoonerfan said:

I use this one with a Merc 150 running 2 Helix 8's, Mega 360 and all my other accessories. It will last all day. 

 

https://www.academy.com/shop/pdp/interstate-batteries-deep-cycle-group-29-840-marine-cranking-amp-battery#repChildCatid=6440505

 

X2 on this.  I have a Merc 115 and I leave my electronics on all day long.  I have this for a cranking battery:

https://www.interstatebatteries.com/products/27m-xhd?productLine=marine&subcategoryKey=&ignorecategoryid=true

 

It's only a group 27 and its SIX years old and working perfectly.  I keep the proper amount (and type) of water in them and I keep them fully charged (floating) when not using them (year round).  

 

Also, why are your batteries leaking?  I suggest you figure that out because there's absolutely no reason they should be "leaking".  

[Dirtyeggroll]

If you can find the Duracell 31 AGM at a Sam’s club nearby, they are the best bang for the buck 31 series size AGM. A great battery!

[CaptainB]

Thanks for all of the replies.

 

Thanks for the battery recommendations.  I thought it seemed early for the batteries to be leaking too.  The batteries came with the boat and are Golden Eagle lead acid batteries.  I installed a Cabela's 20A 3 bank charger last year so since it's fairly new I don't think it's over charging them.  I have used interstate batteries on another boat and never had a problem with them leaking at all so I thought maybe it's the brand of batteries or maybe these have been beat on more.  What made me notice was I slammed a 3 foot wake straight on so I was looking a bit more closely when I plugged in the charger that night. 

 

I keep meaning to put the jumper cables in for an emergency but haven't yet researched if I attach them to 1 battery that is run in series with another to produce 24v if that would only provide 12v since it's only attached to the 1 battery.  I'll check that with my multimeter this week.

 

My trolling batteries are 27s but unfortunately I don't think I can fit a bigger cranking battery.  

 

I hadn't thought about building my own lithium battery.  I think that's a little beyond me right now.  I'd be afraid I'd do something wrong and it would catch on fire like some of the Tesla's used to.

 

The Sam's club near me is out of the Duracells.  Batteries plus has these https://www.batteriesplus.com/productdetails/sli27magmd on their website.  I'm going to call them to make sure they have them and if so try them for the trolling batteries.  I'm going to try this one for the cranking battery https://www.batteriesplus.com/productdetails/sli24agmdpm.  Wow, that's a lot for batteries.  I hope they will last 3 times longer than my others.  If they start having problems in 2 years at least they will be under warranty.

[Log Catcher]

If you go with AGM batteries you may have to get a different battery charger. Going by different things I have read a charger for a standard wet cell battery will not work with AGMs. I'm not an engineer so it can't explain what the difference is in charging them or why it makes a difference.

[K1500]

18 hours ago, K1500 said:

Throw some jumper cables in and you can always jump your main motor from one of the trolling motor batteries. 

He fishes alone and far from the ramp. The jumper cable suggestion is in addition to replacing his batteries. Some folks don’t think of it, and he mentioned how he really wants to endure his boat starts. Even new batteries can go bad and jumper cables can save a tow or a really bad day. But...you probably knew that. 

[jbsoonerfan]

6 minutes ago, K1500 said:

He fishes alone and far from the ramp. The jumper cable suggestion is in addition to replacing his batteries. Some folks don’t think of it, and he mentioned how he really wants to endure his boat starts. Even new batteries can go bad and jumper cables can save a tow or a really bad day. But...you probably knew that. 

I used to carry jumper cables and had to use them once before I bought a new battery. I now carry a NOCO jump starter.

[WRB]

XCA27-1000 VMax Tank marine AGM cranking battery.

Usually a 10% discount available.

When I sold my boat this battery was 10 years old and still going strong. Merc 115 Opimax with all the bass boat electronics, pumps, running lights etc. 

Good cranking battery.

Tom

 

 

[CaptainB]

Yep, I checked my charger and it says it works with either lead acid or AGM batteries.  I also asked the guy at batteries plus and he thought it would work.  I didn't order them yet though as they don't place the factory order until Thur. and then they would be in the following Tuesday.  I might go with something different if I can find them sooner.  

[WRB]

Wet cell battery boils out water electrolyte when over charge or over filled. What kills your wet cell is oxides debris falling off the lead plates shorting out the cell after time. Over charging boils the down exposing the plates, then they short.

AGM’s can also be overcharged killing the battery, so make sure the onboard charger isn’t over charging more then 15A @ 13.5VDC then automatic shutting off.

Look up a dealer near you for the battery of interest within your budget. Lithium deep cycle battery needs a specific charging system, so factor the cost in vs weight saving.

Tom

  

[Shimano_1]

I just replaced my cranking battery in my triton 18tx last weekend.  It was less than 2 years old but I recently upgraded to helix 12's and they were killing the 24 series that came with it. I went with the duracell agm 31. Ive ran these before and for the money I've had excellent luck. Plan on replacing both of my trolling batteries in the near future with the same battery in the 27 size. My boat is aluminum and rumor has it the acid from wet cells doesn't play well with aluminum.  So...for piece of mind etc ill run agm's. Like u I have no desire nor the wallet to replace them with lithiums.

My rig has the mercury 115 pro xs 4 stroke

[gim]

22 hours ago, jbsoonerfan said:

I used to carry jumper cables and had to use them once before I bought a new battery. I now carry a NOCO jump starter.

I carry both! The power pack stays with the boat during the season and the jumper cables stay in the truck. In the winter they are both in my truck.

[CaptainB]

Tom, when you say make "make sure the onboard charger isn’t over charging" is that as simple as attaching a multimeter to the battery terminals when the charger is charging to check the voltage and amperage then making sure it turns off (I've only used it to check volts)?  Unfortunately I've lost my manual and receipt so I'm not sure what the charging profiles of my charger are supposed to be.  I think it should still be under warranty if it's not charging correctly.  Would a damaged battery cause an automatic charger to appear to be overcharging?  It's a 20 amp 3 bank charger and the way I think it's supposed or work is adjust the charge rate as needed so if one battery is damaged I wonder if it would be dumping higher amps into it.

 

Shimano_1, I checked my compartment again today.  It's 39 inches wide with my pump hoses on the left side and I just don't see how I could come up with 2 more inches to upgrade to a 27 cranking battery much less a 31.   I looked at the specs on the Duracell 31 and that looks perfect for our engine.  Mine's aluminum too, a Lowe Stinger 188.  I have a 9" screen on the console and 5" on the bow and if I was staying in one spot for a while I had to put the 9" in standby or it would drain mine (not so much the first year but this year the battery became noticeably weaker).