dead battery charger?

Is it common for a battery charger to die or malfunction?

Put my deep cycle (less than 1 yr old and always charged after every trip) for the trolling motor on the charger overnight before heading to a trip on the Canadian border this last weekend. Charger said battery fully charged. Got out on the lake and the prop would barely spin. Got home, put it back on the charger this morning and the charger still says it’s charged. Tested the battery and get a measly 10.8 volts, so the charger is clearly not functioning properly. And now I’m worried that my brand new deep cycle that I religiously keep charged, has been sitting at under 11 volts for possibly a couple weeks since I had the boat out last.

The charger is not an onboard deal, its a DieHard deal from Menards. Have used it without issue in deep cycle mode for a few years.

My next question — how do people like the Noco Genius chargers -vs- the Minn Kota chargers? I only have a 12v system so I am looking at the MK 110pc -vs the Noco Genius 10×1.

Thanks!

Yes things fail…get a new charger. Also, some of the new “smart” chargers will not charge a battery below a certain voltage, could be a chance that is your issue also. Ive seen wires inside cord break on some chargers, s lot of things can cause the failure.

When was the last time you checked the water level in your batteries also?
I am a minnkota charger myself, ive currently got 3. I did have one fail that was about 15yrs old that was always plugged in.

Is it a charger or a maintainer?
As Mark said most maintainers wont charge a depleted battery.

Thanks Mark. Water levels are good, it’s seen minimal use — maybe 10 hours total since September as I don’t use the TM all that much.

The Noco 10×1 says it can charge batteries as low as 1v in regular mode, and has a “force mode” that allows manually charging a totally dead battery. I don’t see any mention of that on MK’s website.

Can you have your battery tested? I had put a new starting battery in my old boat (FF Resolute brand) at the end of summer 2 years ago. The next spring it wouldn’t charge. Took it back to FF and they said the battery was bad. It was still under warranty so they replaced it free of charge. It didn’t make me want to put another Resolute battery in it again though.

Jeff Gilberg wrote:

Is it a charger or a maintainer?
As Mark said most maintainers wont charge a depleted battery.

It’s a charger. Been using it for years to charge my deep cycle TM batteries. It puts out 10amps and has a deep cycle mode.

bzzsaw wrote:

Can you have your battery tested? I had put a new starting battery in my old boat (FF Resolute brand) at the end of summer 2 years ago. The next spring it wouldn’t charge. Took it back to FF and they said the battery was bad. It was still under warranty so they replaced it free of charge. It didn’t make me want to put another Resolute battery in it again though.

Did you need the receipt to do that? Mine is an Interstate, also from Fleet Farm. They etch the date of purchase and some other stuff on there. Just purchased in September so definitely in warranty.

if you have a load tester you can test the battery. if not you can get a load tester from harbor freight for $20 or take the battery to most auto parts stores or fleet farm and they will load test it for free

https://www.harborfreight.com/100a-612v-battery-load-tester-61747.html

excellent tool to have at home

Coletrain27 wrote:

if you have a load tester you can test the battery. if not you can get a load tester from harbor freight for $20 or take the battery to most auto parts stores or fleet farm and they will load test it for free

I thought a battery needed to be charged in order to do an accurate load test? My battery is reading 10.8v on the multimeter so it’s definitely not charged.

yes i guess you are correct on the load test with low voltage.

Most auto part stores will charge your battery then test it. I delivered for Advance for a while after I retired. We often had 2 or 3 batteries on our charger for several hours to bring them up to a level that they could be tested.

Got a buddy with a charger you can try? That would tell you if it’s the charger or battery. I’m in Maple Grove, if you’re nearby.

Gonna bring it into the Oreillys in my hood, they will charge and then do the load test. I’d be surprised if it’s the battery but worth ruling it out so I don’t waste money on a new charger for new reason.

O’Reilys digital tester has a starting battery setting and a marine/rv setting. 99% of the batteries they test are auto starting batteries so make sure they set it to marine/rv for your test.

Pat K wrote:

O’Reilys digital tester has a starting battery setting and a marine/rv setting. 99% of the batteries they test are auto starting batteries so make sure they set it to marine/rv for your test.

Thanks I’ll be sure to make that clear.

Big thanks to those who chimed in with ideas, especially those who suggested it could be the battery itself.

Took it to Oreilly’s, they tested it and it came out bad. Took it to Fleet Farm, they confirmed it with their machine and replaced it under warranty.

Brought it home, multimeter said 12.5v, put it on my charger and it appears to working exactly as it should.

I read the instruction manual and didn’t find any info to confirm this, but I suspect that the charger saying “charged” when the battery was at only 10 volts and change, was the charger’s way of saying the battery was too low to charge. They should have a separate indicator for that, but it’s a crappy $50 charger going on 10 years old.

I think I’ll still be getting a better charger. That Noco that can charge from 0v is definitely intriguing to me.

My old Guest 3-bank would do the same and it was frustrating until I knew how to identify a dead battery. Ended up getting over 20 years out of that unit. Just replaced it last week with a ProMariner. They are on sale at Cabelas so I could instantly pick it up cheaper than anywhere online.
Check out my Charger post in the Outdoor Gear Forum still on page 1. There’s some good charger info in there.