Main Battery Draining

[BAROHIO]

Battery, charger or boat issue??? I have a 2020 Z18Pro with 10' Talons, Ultrex 24 volt and just two Helix 7's. I noticed toward end of day my Hummingbirds were shutting down with low voltage warning. Boat came with a NOCO Gen3 and the main battery is an Interstate 31M-AGM CCA 800 and 1190 MCA. I keep the charger on 24/7 when not on the water and yesterday I noticed all my Talon lights were both blinking. I checked the charger and see the flashing error on the main battery bank. I checked the voltage on the battery and it had dropped to a 2.4 even after being on charge! Drove off to an authorized Interstate Distributer. After checking the battery and looking at the charger he's telling me the problem isn't the battery it's either the charger or something in the boat drawing AMPS. He said the charger is not designed to charge and maintain the AGM31 if the AMPS drop too low…I spoke with NOCO and they say it's not the charger it's the battery. What's your opinions?? What in the boat could be draining the battery while it sets for awhile but always on charge?? Frustrating to say the least! Thanks for all your knowledge..

[Andrebass]

Shut off main power in bilge before charging.

[BarryFL]

Battery, charger or boat issue??? I have a 2020 Z18Pro with 10' Talons, Ultrex 24 volt and just two Helix 7's. I noticed toward end of day my Hummingbirds were shutting down with low voltage warning. Boat came with a NOCO Gen3 and the main battery is an Interstate 31M-AGM CCA 800 and 1190 MCA. I keep the charger on 24/7 when not on the water and yesterday I noticed all my Talon lights were both blinking. I checked the charger and see the flashing error on the main battery bank. I checked the voltage on the battery and it had dropped to a 2.4 even after being on charge! Drove off to an authorized Interstate Distributer. After checking the battery and looking at the charger he's telling me the problem isn't the battery it's either the charger or something in the boat drawing AMPS. He said the charger is not designed to charge and maintain the AGM31 if the AMPS drop too low…I spoke with NOCO and they say it's not the charger it's the battery. What's your opinions?? What in the boat could be draining the battery while it sets for awhile but always on charge?? Frustrating to say the least! Thanks for all your knowledge..

I've had several NOCOs and they've been flawless. Interstate Batteries, not so much.

[jimsch]

Charge it best you can and take it to an auto parts house to load test it to get another opinion from someone else.

[BMCD]

rule out the battery, get a full charge on it. prolly need some other charger to get charged enough for the batt charger to take over.

....and check inline fuse.

[steinybass]

I have a 2019 Z19. I just had my interstate cranking battery replace this April. It passed every test they had but they guy from interstate figured lets try one other test. So he did an amp hour test and that he said failed miserable so they warranted my battery. I fished Dec 31 2021 and thought the start up sounded odd. Then fished twice in March and had to jump it 3 times, My warranty was to run out in April. So I would ask the to run an amp hour test that isn't something that they require to check from what he told me.

[bignitromike]

The Talons have circuit boards that go bad Had it happen couldn't figure out what was draining the battery.

[Mcjenson]

That noco charger will shut off after 24 hours of the battery is under load. You have to kill the main circuit breaker for it to charge properly. Also, ask interstate to do a full deep cycle test. It takes a few days, but they can fail that and still pass the starting test.

[Pat Dilling]

I have had nothing but bad experience with the Interstate AGM 31 series that come with the new boats. We have a 2021 Z19 with 200 Pro XS 4 Stroke. Had similar experience to you, mine wasn't lasting the day and had to jump start several occasions. They replaced one under warranty, 4 months later same thing. I said to heck with the Interstates and ordered an Odyssey 31M-PC2150ST-M. Mercury calls for an AGM battery with 975 CCA for their bigger 4 Stroke motors. The Interstate is underpowered with only 925 CCA. The Odyssey has 1150 as do a few others like the X2 and Northstar. Over a year now with the Odyssey and no more problems.

[paultangherlini]

i have a 250 pro xs mercury 2020 i run four graphs 3 -12s and one 15 all solixs plus the live with the 360 and the live scanner i have all lithium's that are all ionic batteries i have two 125 amp hr cranking batteries run in parallel for my motor and all my accessories graphs ext and 3 100 am hr batteries for my ultrex i pilot link 112 thrust trolling motor i went out today for 5 hrs the two 125 am hr were at 92 percent each and my tolling motor batteries were at 96 percent each now before anyone says anything i researched this a lot i called mercury themselves and they said they dont recommend the lithium's but they will still honor the warranty no problem and i asked why they dont recommend the lithium's and the factory said there hasn't been enough data done on them OR WITH THEM with the new engines they also said that about ten years ago they had problems with back charging with the lithium's i said oh ok i so i dug a little further i called ionic and talked to the head guy they and hes been doing it for about 25 years and he said years ago the lithium's had different chemicals in them and they didn't have the new BMS battery management system which prevents the lithium's from back charging or in plain English sending NO ELECTRICAL PULES BACK TO THE MOTOR MAKING THEM 100 PERCENT SAFE FOR TODAYS ENGINES i hope this clears up a lot of questions but if no one belies me call mercury motors and ionic batteries to confirm what i am saying all i know is the system i have done in my boat is the ultimate in power and can last for a few days and it works great

[Nutt]

I have the same issue with my 2017 Merc 150 4 stroke. Had my cranking battery go dead after thirty minutes on the water in February during a tournament. Replaced the battery thinking it had just gotten old and may have dropped a cell. Nope. I Fully charged the new battery, unplugged the charger, and a couple of days later....dead cranking battery again. I took the battery out and used a different charger, put back in the boat and same thing. Long story short, I took the boat to the dealer and they said the alternator was drawing the battery and this new battery was dead as well, so I had them replace it. BTW, the motor was ONE MONTH out of warranty, so I paid the 952.00 for all of this. Everything has been fine since then until two weeks ago, the same thing happened. I guess I will have to take it back in again. I sure wish I could get this figured out. To me, theres not much worse than electrical issues. BTW, I have 8' PP Blades, a 12" Lowrance and 9" FS 9 with AT running off the battery. I also have a cut off switch for the Power Poles.

[JR19]

1. To eliminate a parasite amp draw make sure everything is wired through a disconnect and the disconnect is off when the boat is not in use. Its common to have a auto bilge pump wired so it has 24/7 power but that type device should not have a parasite amp draw.

2. you never mentioned the reserve capacity of your battery. This is often the most overlook battery rating and it is the most important battery rating for running accessories when the big motor not running to charge the cranking battery. Based on the load you have described the battery has when your fishing I would want at least 200 minutes reserve capacity.

Now I dislike to name bash but based on my 1 experience with a Interstate marine cranking battery and numerous post I've read here on BBC Interstate batteries lack in quality. It may test good or look good but they are weak in my opinion. I feel like a disconnect to kill all parasite draw when the boat is not being used and a good quality 31 AGM with enough cranking amps for your motor and enough reserve capacity to support you demand when fishing will resolve your issue.