I have a Noco charger on a 2019 Tracker...I go through deep cycle batteries for my electronics more than I should. I just replaced a bad one I got from Autozone that was less than 8 months old.

They replaced it for free, but I’m worried in a few months it’ll [censored] out again.

I’ve owned the boat for 2 years and I’m on my 3rd deep cycle battery...is that common or is something wrong?

Thanks y’all...

Which battery, are you keeping the electrolyte up, are you getting a full charge? No... Something is wrong!

check the voltage on the battery.

When?

You say you "go through deep cycle batteries for your electronics more than you should". You need to tell us how many batteries are in the boat, and what connects to each one. How many banks does the charger have, and are you charging all of the batteries, including the one in the application that has been an issue?

Do you own a digital voltmeter? If not, buy one. Check voltage when you return from fishing (all batteries). Plug charger in, check voltage again for each battery. You should see a noticeably higher voltage on each battery while charging. Report back here with results. Do you get to "100% charged" status for each bank? Does this include the battery used for electronics? Do you leave the charger plugged in, or do you unplug it?

Some thoughts:
1) You could have a bad bank on the charger, but there is not enough info to declare that yet.
2) The load you put on the battery may be too much for what the battery is designed to handle. You haven't explained loads or given any insight into what battery and it's Amp-Hour rating. You'll need to provide much more info to get meaningful help. Wet cell lead acid batteries suffer reduced life if routinely discharged to less than 50%. (That's not 6V, by the way.)
3) If you are unplugging the charger for long periods of time, you could have some load that is constant that discharges the battery anytime the charger isn't keeping it up. Example: power for NMEA devices.
4) As said by others, do you ever fill the battery (not to the brim) when you get a new one and check it thereafter? Most deep cycle batteries are rarely "maintenance free." They always come low; add only distilled water, very carefully/sparingly. Know the proper fill level for a battery before you do this.

I had the same issue about six months ago. After going through numerous batteries and troubleshooting... I finally looked at the NOCO battery charger. The issue is, it was overcharging the batteries... when it should have been shutting down when the batteries were fully charged. I took the charger to Batteries Plus and they trouble shoot it and found the problem...two or the four chargers were bad. Changed out the charger and everything fixed.

While I do not doubt your story, it's probably the exception rather than the rule. Electrical items (especially those sealed from the outside environment) rarely fail in the big scheme of things. Much more common are interconnect issues. Example: A gentleman ready to blame a battery and replace it when he had crimped a new ring terminal on the charger lead using regular mechanic's pliers. That was his issue, not the battery, or even the charger. In other words, owner/user/installer error or lack of understanding accounts for far more trouble than actual device failure in the end.

My boat only runs 2 batteries...a cranking battery and a deep cycle for running electronics.

The charger on board is a 2 bank.

I’ll go by a volt meter today and start checking.

I keep it plugged in my garage as soon as I get it home because I read that’s what is healthiest for battery life because these chargers are supposed to know when to charge and when shut off.

Ive never blown any fuses so I don’t think I’m overloading the battery when I operate my boat, and I haven’t made any modifications to the boat except moving the fish finder to the front when I bought a Garmin for the console.

Other than that it’s pretty much factory...

Also, I did have 1 NOCO charger go bad on the boat 1 year ago and Cabelas warrantied it for me and replaced it for a brand new one.

I second the post above about the charger being faulty. I had this same thing happen around 4-5 years ago. ProMariner Charger. One bank went out on the charger but it appeared to be charging. After meter testing while plugged in to charge I realized it wasn't pushing the amps like the others were. I replace 3 batteries before I started asking questions, thanks to some nice folks on the other site, they helped me narrow it down.

Replaced the charger and never had issues after that.

You're correct that the smart chargers can do fairly well in maintaining a battery. They will occasionally do a "desulfate" cycle to extend life. I currently own 4 NOCOs, and may be buying a 5th. I've owned a couple of them 5+ years. I've never had ANY battery charger go bad actually - over a multiple-unit ownership period of several decades. One that's probably 20 years old at this point is still in use by my SIL.

Not blowing a fuse means nothing with respect to "killing" a battery, btw. Example: leave headlights on (when they don't turn off automatically) and you'll trash a battery, but never blow a fuse. But, I admit it doesn't sound like you have much load. The load you know about may not be all. I wonder if something is on when you don't know it. However, the charger being usually connected should counteract that.

You did not say what size battery you have, btw. No trolling motor on that battery? You also did not say if you ever check the electrolyte - it's always low for shipping, and they expect the purchaser to add distilled water to the proper level, then charge the battery, which should always be done after adding distilled water.

Checking voltages as I stated before will give insight into whether the charger is working as we should see the voltage go up. Another item to buy (auto parts) is a hydrometer. This is a simple tool that lets you check the specific gravity of the electrolyte in each battery cell. That will indicate the health of each cell. The hydrometer will have scale and explanations. They are ~$10 typically.

And you anecdotal experience helps solve his problem how? For every "bad charger" issue, there are probably 50X to 100X "other" issues that occur, such as faulty connections, even people not understanding they must check electrolyte level in flooded cells, etc. This OP has not yet said if he ever checks the level, so there are a number of hurdles that need to be considered before jumping to "bad charger" simply because someone had that happen in a different case.

My anecdotal experience has taught me to expect the unexpected.

Once he wastes his time doing the battery levels, buying new batteries, playing in the mud, etc...he could have easily pulled out a multi-meter and tested the load being delivered while in charge mode.

If there anything less than 13 amps being read...you have a dead bank on your charger.

Been there, done that, bought the dunce cap.

I suggested the investigative steps much earlier - he's getting a DVM as he doesn't own one. I'd like you to explain "testing the load" thing you'd do. Do you have a clue what you are talking about? There is no "load" when charging. Amps when charging can be meaningless. A fully charged battery won't result in any amperage delivery from the charger. He'll be checking the VOLTAGE while charging - eventually.

I don't have a NOCO. However, my charger went "bad" and was starting to kill my batteries. Took a few batteries to figure it out. I replaced the charger and that solved the problem.

You got me there..volts not amps

You win have a good weekend

I appreciate you guys lending assistance...I’m pretty ignorant on this stuff but I’m learning.

My goal is to avoid spending extra time and money on something simple...I boat captain for high school team locally and want to avoid any issues once the season starts back up.

I’m a little confused on how to actually test the charger itself with a voltmeter...(I’m actually in Allen as we speak picking one up)

But I’m gonna check some YouTube videos and try and see if I can get a better idea on what it looks like and what I’m looking for exactly. Never learned the inner workings of electrical systems, so I’m on hind tit as far as that goes.

My goal is to eventually add another battery and a stronger trolling motor..., but it’s one hurdle at a time.