A few newb questions about batteries...

[Mustang65fbk]

I bought my 2004 GW 228 Seafarer in October of 2021, have fished her for two seasons now without so much as a hiccup, but yesterday while I was fishing I got a "low voltage alarm" notification on my Garmin unit. Today, I planned on bringing the boat in off the buoy for the winter and get her all cleaned up, so I paddled out and tried to start her up but the battery was dead enough to not be able to start. I threw the jump pack on the "starting battery", selected the "1" position on the battery switch so that it was just using the one battery to start the motor and not be potentially drained down by the other battery, if that was the problematic one. Still couldn't get her to start, and I even tried a couple different combos with the battery switch, such as leaving it in the "all" or "both" position, which is what I was told from the dealership to do. Anyway, both batteries appear to be Group 24's and there is one "starting battery" and one "cranking battery", of which I'm assuming that the "starting battery" is the one that starts the motor? Both "starting battery" and "cranking battery" sound almost synonymous to me, but I don't know very much about marine batteries. The other question that I have is that the "starting battery" doesn't have a manufacturers date on it, but the "cranking battery" does, which it shows a "3" that is punched out of the sticker, although the months are abbreviated below and none of those are punched out. Is it possible the "3" on it is for the year and was last replaced in 2013? If so, that's rather impressive, though as stated above I bought the boat used and I have no idea when the batteries were last replaced. I haven't done anything to the batteries or really much to the boat since purchasing her in October of 2021, except a new GPS, so the "3" definitely isn't 2023 or anything. Anyway, should I replace the batteries exactly how they are with buying one "starting battery" and one "cranking battery"? They've got them at Costco for about $80 a piece and figure I should just replace both at the same time, since both are a bit uncertain in regards to age at this point. Thanks in advance!

 

[loubeer]

If you're not sure of the age of your batteries - I suggest that you replace them. I religiously replace batteries every 4 years (I have 4 batteries on my 330 Express) - it's just not worth worrying about the battery's condition when 60 miles offshore. I have had great service from DEKA Marine Master Deep Cycle Batteries (all 4 of mine are DC27's - 705 Amp). I'm sure they make a size 24. East Penn is the manufacturer of DEKA batteries - I understand that the West Marine batteries are also manufactured by East Penn and, when bought on sale, they can be competitively priced.

Not sure if it's technically correct, but my batteries are all the same - I don't fool around with, cranking, starting or house designations. I've never had a problem.

 

[Fixit]

every engine needs its own starting battery (same thing as a cranking battery) then you want a deep cycle battery for the electronics, pumps etc.
using a deep cycle for cranking duty or having a long deep discharge off a cranking battery are both very bad for the longevity of said battery. use the correct battery for the application!

 

[Hookup1]

Yes - replace them. Just did all 4 on mine. I'm using Duracell Marine AGM batteries from Sam's Club. I use the 34's for starting batteries (Yamaha 150's), 34 for the bow thruster and the 27 for the house battery. Great price and have not had any problems. Also made by Eastern Penn

Search for duracell marine agm - Sam's Club

www.samsclub.com

Make sure your charger supports AGM. I'm using ProMariner ProSportHD 20.

 

[Coastboater]

My new Grady came with identical AGM’s from Deka.

 

[Mustang65fbk]

Thanks for the replies. Here are a couple pictures of the tops of the batteries currently on the boat, I'm assuming the "24" on the first picture of the battery means it's also a Group 24? Also, as mentioned in the first post, the first battery doesn't have a date on it. Costco mentioned that they do have AGM style batteries but they're about $200 a piece compared to the standard ones which are about $80 a piece. Should I stick with the 24's or is there any reason to go with a 27 instead?

 

[Doc Stressor]

I have gone 7 years between replacements using Deka 27M6 flooded cell batteries in my last 3 boats. These are listed as starting batteries but are actually dual-purpose given the 182 minutes of reserve capacity. I leave my fish finder on full-time when I bottom fish and turn on the bait well pump every 10 minutes for about 2-3 minutes. I've only had one of these batteries fail and that was replaced under warranty. I'm due to replace mine in Dec. They still pass a load test with flying colors. These are basically maintenance-free batteries even though they have ports for adding water. They have a recirculation valve that regenerates the electrolyte by capturing hydrogen gas.

I and several of my friends have had problems with the Deka AGMs sold through West Marine. The cases swell and cells short out in less than 2 years. We think the problem has to do with very high ambient temperatures in Florida. You should be fine with AGMs in the Seattle area.

The state-of-the-art is now lithium batteries and prices are falling drastically as more brands come on the market. There are drop-in replacements for starting batteries that cost about the same as AGMs. In theory, they should last longer. But they don't have an established track record as yet.

 

[Hookup1]

I'm using Duracell Marine AGM batteries from Sam's Club. I use the 34's for starting batteries (Yamaha 150's), 34 for the bow thruster and the 27 for the house battery. Great price and have not had any problems. Also made by Eastern Penn. Make sure your charger supports AGM. I'm using ProMariner ProSportHD 20.

Group 34 43.10 lbs. 955 MCA 55 AH. $134.86
Group 24 52.40 lbs. 800 MCA 78 AH. Did not see availability at my store. Use 34 instead.
Group 27 61.55 lbs. 900 MCA 92 AH. $199.28
Group 31 67.35 lbs. 1,000 MCA 105 AH. $214.32

I would use Group 34's instead of Group 24's or 27's.

 

[Mustang65fbk]

Thanks for the replies so far... I rarely ever do any sort of fishing other than trolling for salmon, so the outboard is essentially always on and as mentioned, I rarely ever kill the motor to do any drift fishing and/or drift fishing with a ton of electronics on or anything. As mentioned, I have a pretty limited amount of electronics onboard... just a Garmin 943xsv, VHF, a few lights and a stereo. No radar or really anything else that should take much in terms of battery power I wouldn't think, and a couple of downriggers but again those are only used when trolling and the motor is running. So, I can't imagine that I'm really taxing the batteries too terribly much or anything, except maybe to start them up for the first time at the beginning of the day.

 

[Harrysea]

Lots of good info here about batteries. Regardless, make sure the battery you use for starting has the appropriate cranking amps for your motor. Also, do you run a charger on your batteries when not in use? I think having a smart (variable amp) charger connected when batteries are not in use is one of the best ways to not only ensure batteries are always ready to use, but to extend battery life.

 

[SkunkBoat]

Your single engine Grady will have the standard setup of a 1/Both/2/OFF Battery switch.
Your batteries are 24M which means they are Marine "Starting" batteries. As mentioned above, they may have some Reserve capacity similar to a 24DP (Dual Purpose). Dual Purpose batteries are a compromise between a Starting and a Deep Cycle (DC). Unless you reconfigure your House power separate from your start power, you should not use a Deep Cycle
You probably would have a hard time fitting a pair of group 27 batteries in the space.
Your simplest solution is to replace both batteries with both 24M or both 24DP lead acid batteries. They should be fine for your stated use.
Walmart is a good source for 24M and 24DP batteries.
I'll get blowback from this statement but I haven't drunk the AGM koolaid yet. I have them in brand new cars and vans and they haven't lasted more than 3 years and they are expensive.

The "House" power is connected to the COM or FEED post of the switch. The same post as the Motor. That means the House 12V runs on the motor and the battery connected to the motor.
Your bilge pump is most likely directly connected to battery 1 (usually Stbd side).
If you needed a dedicated House battery, there are ways to separate the House from the Start. The Blue Seas ACR is an easy way to do it. Then it would make sense to use a DC battery for the house.

The Blue Seas ACR can also be used to always charge BOTH batteries even though you only use position 1 on the switch. I recommend that.

The motor only charges the battery that started it, based on the switch position. The standard setup requires YOU to remember to use Battery 1 half the time and Battery 2 the other half.
Some people run on BOTH because it will then charge BOTH. Defeats the purpose of having a switch and two batteries. Basically, they have one battery instead of two. They don't have a "backup" starting battery.
But the dealer told them to do it that way so hey, what do I know....

 

[Mustang65fbk]

Lots of good info here about batteries. Regardless, make sure the battery you use for starting has the appropriate cranking amps for your motor. Also, do you run a charger on your batteries when not in use? I think having a smart (variable amp) charger connected when batteries are not in use is one of the best ways to not only ensure batteries are always ready to use, but to extend battery life.

I haven’t used a battery charger over the last two winters and up until yesterday it hasn’t been a problem. The boat doesn’t have a plug for shore power and I don’t think the boat has any sort of battery charger other than the alternator on the outboard to recharge them.

 

[Mustang65fbk]

Your single engine Grady will have the standard setup of a 1/Both/2/OFF Battery switch.
Your batteries are 24M which means they are Marine "Starting" batteries. As mentioned above, they may have some Reserve capacity similar to a 24DP (Dual Purpose). Dual Purpose batteries are a compromise between a Starting and a Deep Cycle (DC). Unless you reconfigure your House power separate from your start power, you should not use a Deep Cycle
You probably would have a hard time fitting a pair of group 27 batteries in the space.
Your simplest solution is to replace both batteries with both 24M or both 24DP lead acid batteries. They should be fine for your stated use.
Walmart is a good source for 24M and 24DP batteries.
I'll get blowback from this statement but I haven't drunk the AGM koolaid yet. I have them in brand new cars and vans and they haven't lasted more than 3 years and they are expensive.

The "House" power is connected to the COM or FEED post of the switch. The same post as the Motor. That means the House 12V runs on the motor and the battery connected to the motor.
Your bilge pump is most likely directly connected to battery 1 (usually Stbd side).
If you needed a dedicated House battery, there are ways to separate the House from the Start. The Blue Seas ACR is an easy way to do it. Then it would make sense to use a DC battery for the house.

The Blue Seas ACR can also be used to always charge BOTH batteries even though you only use position 1 on the switch. I recommend that.

The motor only charges the battery that started it, based on the switch position. The standard setup requires YOU to remember to use Battery 1 half the time and Battery 2 the other half.
Some people run on BOTH because it will then charge BOTH. Defeats the purpose of having a switch and two batteries. Basically, they have one battery instead of two. They don't have a "backup" starting battery.
But the dealer told them to do it that way so hey, what do I know....

I agree and I think that I’ll just replace them with the same or similar Group 24’s, which is what I currently have on there. I’ve also heard some mixed things about the AGM style of batteries, and at Costco they’re also more than double the price ($200 each) of the standard ones, which are only $80 a piece. I also am not sure how much space I have in there and yes, the Group 27 batteries might be a tighter fit or not even fit at all. I think the worst case scenario would be for me to have what happened yesterday where I row out to the boat and it won’t start. If it was doing some serious offshore drift fishing or something similar where there was a possibility of getting stuck 50-60+ miles from home then that would be something else to think about. Fortunately I’ve got Sea Tow on my insurance policy as well as neighbors that I could call, if there was ever any sort of an emergency. And likewise for them where they could always call me.

 

[Hookup1]

Sorry but I don't have the time to play with all these "what if's". Put AGM Marine batteries in. My choice is Duracell but whatever. Charging shunts from each motor in the case of twins (charge 4 batteries). Make sure your charger can handle AGM's.

 

[Coastboater]

Isn’t the OP on a mooring ball? Other than solar, negates a charging system.

 

[Peter A]

It is odd that both batteries seem to be bad at once. No? For sure they are likely due for replacement but you may have a charging system problem. in my (automotive, not marine), a low voltage indicator with a running engine is a charging system issue. Not sure what gauge package you had but did the engine gauge (not the GPS) indicate low voltage while running?

When you went to start with the jump pack, I presume it was completely charged. Did you let the jump pack connect to the battery for a bit, like 10 minutes?

I don’t know how far you go to haul the boat out, it should start and run on new batteries but will discharge them. Would hate for you to smoke a new battery. Perhaps if close by you can get a tow to haul out and do some additional diagnosis and battery replacement in a more convenient location?

 

[Peter A]

I would go with quality AGM batteries, they are more tolerant of discharge, and generally more robust. I have not had great experience lately with the quality of batteries. I would use a Marine battery for sure hoping for a better build quality. While most batteries are made by relatively few manufacturers there are differences in the quality level provided for different “brands”. I try to use AC Delco or Interstate branded batteries in the automotive world. Not sure about marine though. Perhaps for fishing in the sound a pair of low cost Costco traditional lead-acid batteries are fine but I would go with AGM.

 

[Hookup1]

Check your battery charger and engine charging system...

This is a basic system test that can be done with a voltmeter. A Harbor Freight voltmeter is good enough. Start here and others can help going forward.

At the dock turns all your electronics on and disconnect the boat from shore power.

Put a volt meter on the starting battery and check voltage. Should be somewhere around 12.8 volts.
Check house battery. Should be around 12.8 volts. This is normal fully charged battery voltage.

Start the motor up. Check starting battery voltage. Should be around 13.1 volts.
Check house battery. Should be around 13.1 volts. This is normal voltage while engine is charging batteries.

Turn the engine off and reconnect shore power. Turn charger on. Both batteries should be around 13.1 volts indicating the charger is working. If you don't get charger voltage check inline fuse from charger at battery if your charger has one - common problem - sometimes they melt fuse holder.

If you have twin engines and a third house battery they are charged thru a shunt wire (engine charging cable) and the third bank on your battery charger. Same procedure as above.

 

[Sauza45]

I just ran into the same thing. Saturday I went out on the boat to go offshore fishing, and when I turned power on I got a message of gps unstable. I went out anyway not thinking much about it and could
not engage autopilot. On the way back in the autopilot worked. connected shore power and then checked the battery yesterday. I had 12.3 on 1 battery and 12.4 on the other batttery. So I went to west marine
and bought 2 AGM battery's. Got lucky they were having 1,000 bonus points and giving 50.00 for every 250 spent. Going 50-70 miles offshore I did not want to chance it. I have had good luck with the west marine AGM
battery.

 

[Doc Stressor]

The best $20 you will ever spend if you maintain your own batteries:

Load Tester

Unless there is severe battery damage, a freshly charged battery will always show 12.6 or so volts. But what happens when you put it under a load like starting your engine? I've used this Harbor Freight piece of junk for 5 years now and it has revealed weak batteries before they failed several times.

You did not specify what engine you have on your boat. Many engines, especially Yamahas, will draw more power to run their pumps and computers than the alternator can put out at low rpm. A big Yamaha 4-stroke can draw almost 20 amps. So they are drawing off the battery at low rpm and won't run without a battery connected. That's why they specify using a battery with a high reserve capacity. Group 24 batteries can't come close to meeting these specs. In fact, most group 27 are not sufficient. You need to check the specifications of the battery you are interested in buying.

Since you live in the Seattle area you most likely do a lot of slow trolling at low rpm or using a kicker. You probably have your chart plotter on all the time and intermittently draw a lot of current with your downriggers. Be safe and use dual-purpose group 27s with the proper reserve capacity. That's what Grady started putting in their boats as 4-stroke outboards became standard.