Fisherpete Posted April 12, 2015 Report Share Posted April 12, 2015 So I got the boat all ready for action today, and hooked up my fishfinder which has a voltage meter. The voltage on my starting battery was 12.1V, and within 10 minutes of having the fishfinder on was down to 11.7V. I've had it for 7 years, Motomaster Nautilus AGM, it's been flawless but I'm guessing it's probably done. It did something like this one day at the very beginning of last season, fishfinder kept cutting out and the voltage was low. I gave it a charge when I got home that day and it was fine for the rest of the season. I charged it a couple days ago just to make sure it was topped up fully. Thoughts? If she's dead, any suggestions for a new battery? I'm leaning towards getting the exact same AGM, which I think is $319 or so. Are they that much better than the normal marine starting batteries? Almost triple the cost... Link to comment Share on other sites More sharing options...
Paudash Posted April 12, 2015 Report Share Posted April 12, 2015 No need to spend that kind of money on a starting battery. I have a Kirkland from Costco, I think they go for around $120 and has worked great for years Link to comment Share on other sites More sharing options...
Garnet Posted April 12, 2015 Report Share Posted April 12, 2015 Load test is the only way to find out. CTC, local garage, you can buy 1 for $50. Link to comment Share on other sites More sharing options...
davey buoy Posted April 12, 2015 Report Share Posted April 12, 2015 After a complete charge Pete it should hold at least 12.7-12.9 volts 24 hours later.Sounding like yours is not so good now. Link to comment Share on other sites More sharing options...
wormdunker Posted April 12, 2015 Report Share Posted April 12, 2015 Charge your battery on a 2 amp (trickle) charge for 2 or 3 days. See if the reading will come up higher than 12.1 volts. $319.00 for a starting battery sounds expensive. I use 2 Nautilus deep cycle batteries from CTC. $165.00 each. In the off season I put them on a trickle charge every 4 or 5 weeks. Batterystuff.com has excellent advice on batteries & chargers. Link to comment Share on other sites More sharing options...
lew Posted April 12, 2015 Report Share Posted April 12, 2015 As Paudash said, go to Costco and pick up a Kirkland battery for around $100 and your all set and don't need to worry about being stranded somewhere on the water. Nothing worse that worrying if things will work or not. Link to comment Share on other sites More sharing options...
Smokercrafty Posted April 12, 2015 Report Share Posted April 12, 2015 If you never charged it over the winter season, then charge it at a very low amperage for a day or two, then try again. Other than that, I'd assume it's toast. Link to comment Share on other sites More sharing options...
Old Ironmaker Posted April 12, 2015 Report Share Posted April 12, 2015 (edited) There are many threads about batteries here. It comes up every spring. What I did learn from researching batteries a few years back is 80% of all batteries are made by Johnson Controls and most of them are made in China. Kirkland is the city Costco headquarters are in, thus the Kirkland name, they are Johnsons. The biggest difference in battery prices are the number of discharges below 20% a battery can have and still hold a charge. Also check the manufacturers date on a new battery, they bring the older stock to the front of the shelves, it's not good for a battery to sit for a long period of time uncharged. I think the battery for a 747 might be $300.00, that's expensive my friend. I don't mess around with my marine batteries, I can't call CAA on the lake for a boost. I carry a booster pack for insurance. CTC will check your battery at no charge. Edited April 12, 2015 by Old Ironmaker Link to comment Share on other sites More sharing options...
fish_fishburn Posted April 12, 2015 Report Share Posted April 12, 2015 Trojan batteries are half that price and last just as long. Link to comment Share on other sites More sharing options...
Mister G Posted April 12, 2015 Report Share Posted April 12, 2015 Pros and cons when it comes to AGM batteries. IMHO I believe they are way over priced but if you don't mind being raked over the coals, go for it. It your money and if you think it's best for your purpose that is all that counts. In my experience a good marine starting battery that is well maintained from day one should last you at least as long as your AGM. When I say well maintained, I mean having a on-board charger hooked up to that battery and all boat batteries whenever the boat is not out fishing. My last marine dual purpose starting battery (wet cell) was replaced at 9 years old because it was 9 years old and I didn't want to push it on the Great Lakes. If I didn't fish the Great Lakes, who knows it might be still in my boat. If you don't already have a on-board charger you should consider one and if you purchase a wet cell marine battery it will be free with the saving of not purchasing a AGM battery. Now got to it and catch a fish Link to comment Share on other sites More sharing options...
porkpie Posted April 12, 2015 Report Share Posted April 12, 2015 Pete, I'd go with the costco advice. I've had great luck, and there is no way I'd spend that kinda cake on a starting battery. Costco has an excellent starting/deep cycle unit for $120. Link to comment Share on other sites More sharing options...
ecmilley Posted April 12, 2015 Report Share Posted April 12, 2015 the agm batterys are nice but do require different chargers to get the most out of them, if your charger has been charging over 14.4vts can lead to longevity issues. as for use a regular dc or dp will work fine as a starting batterey and running a sonar all day. running a dc27 for starting on my ranger and it runs the bird up front the hds on console and my talon never a issue with starting after fishing 7-8 hrs with everything running Link to comment Share on other sites More sharing options...
NANUK Posted April 13, 2015 Report Share Posted April 13, 2015 7 years old ? You can try recharging it however slow or fast you want, chances are it will let you down on the water when you really need it. I would say time to replace the battery, Like mentioned above, no need to spend a lot of money for a cranking battery, get the biggest marine cranking amp battery for the physical size you require for the space you have, I prefer marine rated batteries for the boat, they stand to vibration in the boat better than car batteries. Link to comment Share on other sites More sharing options...
lew Posted April 13, 2015 Report Share Posted April 13, 2015 I always carry a set of booster cables in the boat just in case my starting battery won't fire up my motor. Hook them up to a deep cycle and away you go. And I can help another boater who may be stranded. Link to comment Share on other sites More sharing options...
BFSC Kevin Posted April 13, 2015 Report Share Posted April 13, 2015 Same here. I carry a set of booster cables in the boat. Make sure they are long enough too.. Last year my starting batteries (at the back of the boat) drained somehow and the jumper cables were too short to reach the front where the trolling motor deep cycle batteries were. I could have brought the deep cycle further back to boost the starting batteries but I didn't want to bother untying everything and carrying it to the back. So then I just used my kicker motor to get back to the launch. Took about 15 minutes. When I got back to the ramp I had longer jumper cables in the truck and I was able to boost the starting batteries no problem. I always carry a set of booster cables in the boat just in case my starting battery won't fire up my motor. Hook them up to a deep cycle and away you go. And I can help another boater who may be stranded. Link to comment Share on other sites More sharing options...
BFSC Kevin Posted April 13, 2015 Report Share Posted April 13, 2015 I had three motors in the boat, main, kicker and trolling. Booster cables in case. It would really suck to be stuck on a big Lake and the weather turn bad... Like a storm rolling through on Lake O.. Link to comment Share on other sites More sharing options...
BillM Posted April 13, 2015 Report Share Posted April 13, 2015 I've killed the battery on my main I think twice.. Battery doesn't have enough juice to start the big motor, but it will start the kicker without issue. I'll troll around at WOT on the kicker to charge the battery just enough to get the big motor going. I haven't had this work around fail me yet Link to comment Share on other sites More sharing options...
G.mech Posted April 13, 2015 Report Share Posted April 13, 2015 You have to be careful selecting cranking batteries for some of the modern high tech motors. Many of them require very high cranking current batteries to prevent damage to the ECM. I know the Optimax says minimum 1000 MCA (800CCA) battery which you won't get with a deep cycle or dual purpose AGM. Just something to keep in mind if you're running any of these. Link to comment Share on other sites More sharing options...
irishfield Posted April 13, 2015 Report Share Posted April 13, 2015 What ^ he said. The Verado's battery is supposed to be dedicated to the motor and if you run it down below about 11.2 volts the computer will not attempt to start it (and you're not supposed to boost it). One of the (many) things I had to correct on my boats prewire in 2007 ...as they had the auto bilge pump and a lot of other things hooked to the main battery. All "drain" items are supposed to be on the kicker / accessory battery (that gets recharged through an isolator off the big motor, or the kicker). I have two 1080MCA AGM's in mine, that I made Lund pay for, and if they're good to go again this summer will be their 8th season, so I'm looking at $700 in the near future I bet. Link to comment Share on other sites More sharing options...
Lape0019 Posted April 13, 2015 Report Share Posted April 13, 2015 All good points here. I run interstates and replaced mine after 8 years in the boat. They were charged after every use but just like Mr G wrote, and I only changed it because I didn't want to get stranded. I had left it at my Dads house and he decided to use it because his was toast. Guess what? left us stranded that very same year. If you get 9 years out of a battery, is $300 a lot? I don't use AGM and doubt most of the responses on here were about AGMs but if you can afford it, it is almost worth it to not have to service them. As for trickle charging the AGM, make sure your charger is rated for AGM batteries, many are not and it can really affect the battery. Link to comment Share on other sites More sharing options...
BillM Posted April 13, 2015 Report Share Posted April 13, 2015 If you're getting 8-9 years out of a normal lead acid battery that will use any charger, why bother with AGM? What does AGM do better? From what I've been reading, nothing. Link to comment Share on other sites More sharing options...
Mister G Posted April 13, 2015 Report Share Posted April 13, 2015 If you're getting 8-9 years out of a normal lead acid battery that will use any charger, why bother with AGM? What does AGM do better? From what I've been reading, nothing. Not sure if you will get that many years out of any charger that's why I recommended a on-board charger because they are smart chargers. However, some non on-board chargers very well may be smart chargers as well. Double check on that but then the charger should be hooked up and on charge at all times the battery is not being used. A on-board charger makes this so much easier because you only have to plug the charger in. Link to comment Share on other sites More sharing options...
BillM Posted April 13, 2015 Report Share Posted April 13, 2015 Who's talking about chargers? I'm referring to a normal lead acid battery vs AGM. Link to comment Share on other sites More sharing options...
Mister G Posted April 13, 2015 Report Share Posted April 13, 2015 If you're getting 8-9 years out of a normal lead acid battery that will use any charger, why bother with AGM? What does AGM do better? From what I've been reading, nothing. Maybe I'm reading this incorrectly but you're quoted above saying "that will use any charger". So I mentioned that a non-smart charger may not get you 8-9 years from a battery. Read it again, maybe I didn't type it very clear to understand.......just doing the best of what I can with what little I have.... Link to comment Share on other sites More sharing options...
BillM Posted April 13, 2015 Report Share Posted April 13, 2015 Maybe I'm reading this incorrectly but you're quoted above saying "that will use any charger". So I mentioned that a non-smart charger may not get you 8-9 years from a battery. Read it again, maybe I didn't type it very clear to understand.......just doing the best of what I can with what little I have.... I simply mentioned a 'normal' charger as one of the pros of a lead acid vs whatever special charger you need for a AGM battery. Link to comment Share on other sites More sharing options...
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