Would You Trust This Battery Again?

[SoonerFan]

The last time I went to the lake, I only started the big motor, 150 Merc Opti, to launch the boat and pull to the dock. It seemed to crank a little slow but Optimax's always sound like a 54 Buick when they start. The rest of the time I stayed on the Ultrex. When I went to start the motor to load the trailer, the motor cranked slowly and wouldn't start. Ended up having to do the good old trolling motor load, which means you're driving home in wet shoes and underwear.

When I got home, I automatically plugged in my MK 3 bank 5 amp charger(I wish I had tested it first). I know the charger is a little undersize but it has always done a good job handling the occasional fair weather fishing trips I do. I've always thought that a lower amp charge over a longer period of time was better anyway. The battery is a X2 group 31 AMG 1150 CCA from Batteries Plus. It was in service on 5/16, so it's five years old...one year out of warranty. It doesn't get a hard workout at all. I tend to fish smaller lakes and stay on the TM longer. It didn't get very much use in 2019 and only one trip to the lake in 2020. My only other trip this year, I ran the boat a bunch just to run some old gas out and enjoy being out and running the boat. It had been on the charger on and off for the whole of 2020 so I would have thought it was fully charged. I explain all of this because I'm trying to figure out what happened. I was really expecting longer life out of this battery.

I let the Mk charger charge the batteries to where the lights were solid green. I hooked up the battery tester and it showed just under 13 volts...put the load on it and of course it dropped to around 11.5 and then back to the high 12s. I waited five minutes and load tested it again and it recovered right back to over 12.5....next day still load tested okay. Still not satisfied, I hooked up the 25 amp smart charger. It told me the battery was charged 100% but then went through an "absorption'' process that went from 80% on to 100%. I'm not sure what "absorption" would be.

Now I'm not sure to trust this battery or not. On the other hand, I really don't want to lay out the $400+ to replace it. I'm almost of the opinion that the two years of very little to no use just drew it down. But then why didn't it charge up fully on the 10 or 15 miles I ran around on my first trip? I'm also concerned about the alternator which I can't check until I get on the water. The motor is an 07 but very low hours...probably no more than 150hrs.

[CatFan]

10 or 15 miles of running is a drop in the bucket charging a battery that size. You'd need to run at WOT for hours to charge it if remotely discharged.

12.5V is not a good sign. 12.84V is full charge resting voltage for that battery.

Absorption is the name for the phase of charging after the battery reaches 80%. The charger has no way of knowing what percentage of charge the battery is, so charger manufacturers usually call absorption the period after the charger is able to raise the battery to the charger maximum voltage. This determined by both the state of charge of the battery and the current the charger can supply.

With a 5A charger and not a lot of run time with the outboard, I'd bet your battery is spending a lot of time at less than full charge.

[SoonerFan]

This automotive type charger I have has a desulfurization mode. Should I run that?
Also, the load tester I was using depends on green for good and red for bad. Not too much detail between 12 & 13 just a few hash marks. The difference between 12.5 and 12.84 might be hard to determine. I’ll put the multimeter on it and see what I’ve got.

Thanks for the help!

[yam911]

This automotive type charger I have has a desulfurization mode. Should I run that?
Also, the load tester I was using depends on green for good and red for bad. Not too much detail between 12 & 13 just a few hash marks. The difference between 12.5 and 12.84 might be hard to determine. I’ll put the multimeter on it and see what I’ve got.

Thanks for the help!

I would. Give it a go and see what happens.

Do you have a clamp on amp meter? Kinda neat watching the current flow. Will start off high and then taper to next to nothing when the battery is fully charged.

I am guessing that your battery never got fully charged.

[CatFan]

Do not desulfate an AGM.

Measurement accuracy within a hundredth of a volt is needed to diagnose battery issues

[Tom B]

i get 3-4 years at best for battery to start optimax - i get the biggest 31 wet cell i can with high CCA - last one came from NAPA and has been a good one

only other battery that i have found that works ok is interstate (but not a fan of interstate for TM batterys

[SoonerFan]

12.5V is not a good sign. 12.84V is full charge resting voltage for that battery.

.

I unhooked the 5 amp onboard charger last night and waited the this morning to test it. The multimeter read a solid 12.86, so I’m go into that it fishing…but keep my Weego onboard.

CatFan, I really appreciate your help. You probably saved me from spending 400 bucks prematurely.

[Jake T]

If that X2 battery is the thin plate agm /northstar /odyssey then a 5 amp charger is definitely going to shorten the life of the battery. Northstar actually recommends a 40 amp charger.

[John Jackson]

This automotive type charger I have has a desulfurization mode. Should I run that?
Also, the load tester I was using depends on green for good and red for bad. Not too much detail between 12 & 13 just a few hash marks. The difference between 12.5 and 12.84 might be hard to determine. I’ll put the multimeter on it and see what I’ve got.

Thanks for the help!

The difference between 12.5 and 12.8 can be a bad cell.
10 to 15 miles, or roughly 10 to 15 minutes, with a 60 amp charger is a significant charge, enough that unless you run the battery down again with electronics, it should crank back up easily. At 5 years old, do the preventive thing and replace the battery.

[E-rude_Dude]

If in doubt throw it out. Ask me how I came up with that saying?

[BASStard6344]

If in doubt throw it out. Ask me how I came up with that saying?

Ex-wives , ?

[yam911]

If in doubt throw it out. Ask me how I came up with that saying?

An ex parachutist?

[yam911]

Some will have two batteries. So that either can serve as the other in a time of need.

No need to prematurely throw out a perfectly good battery. Run them both until one fails. Then use the other battery to get home on. Replace just the one failed battery. Then proceed as before.

[E-rude_Dude]

Ex-wives , ?

You win

[SoonerFan]

If that X2 battery is the thin plate agm /northstar /odyssey then a 5 amp charger is definitely going to shorten the life of the battery. Northstar actually recommends a 40 amp charger.

I'm trying to determine exactly what Northstar recommends. I called them and only got a receptionist who is going to have a tech call me back. I'm coming to the understanding that my 5 amp charger is NFG for this type of battery. However, a 40 amp onboard charger is unavailable as far as I can tell, plus that would be a pretty big charger to haul around. These are very popular batteries, what kind of charger is everyone else using?

When I bought the battery at Batteries +, I asked about my Minn Kota 3 bank 5 amp charger. Their reply was as long as it is approved for AGM batteries (which it is) it will be okay. Of course, the other day when I went in there to ask them about this subject, nobody knew nothin'.

The difference between 12.5 and 12.8 can be a bad cell.
10 to 15 miles, or roughly 10 to 15 minutes, with a 60 amp charger is a significant charge, enough that unless you run the battery down again with electronics, it should crank back up easily. At 5 years old, do the preventive thing and replace the battery.

That's exactly what I'm going to do. I think this battery might still be okay but I just don't trust it. I'm 71 years old and fish alone most of the time...sometimes in late fall I'm the only boat on the lake. Also, my two grandsons, 10 & 6 years old, are clamoring to take them fishing, so reliability is important. I might try to fit that old X2 in my pickup, who knows.

[SoonerFan]

Looks like I made the right decision to get a new battery. I took the old one to Batteries Plus and they tested it....bad cell. So it would continue to lay down on me.

[catdude28]

Most with the Northstar use a 10 or 15 amp/bank charger. I agree that a 5 amp/bank charger could shorten battery life. Odyssey, a very similar pure lead battery, has a list of approved chargers for their batteries, and they are all 10-15 amps/bank. My understanding of Odyssey is that a 40 amp charger is only necessary for a deeply discharged battery. I don't see why the Northstar would be any different. BTW, Enersys, the parent company of Odyssey, bought Northstar a year or two ago.

In a correspondence with Northstar a few years ago, my contact there was very keen on Powermania for charging the Northstar. It is not a popular brand here on BBC, but, I have heard that it is better known in the saltwater crowd. The MK PC 10 or 15 amp/bank would be a good choice if you are already looking at MK.

[SoonerFan]

Most with the Northstar use a 10 or 15 amp/bank charger. I agree that a 5 amp/bank charger could shorten battery life. Odyssey, a very similar pure lead battery, has a list of approved chargers for their batteries, and they are all 10-15 amps/bank. My understanding of Odyssey is that a 40 amp charger is only necessary for a deeply discharged battery. I don't see why the Northstar would be any different. BTW, Enersys, the parent company of Odyssey, bought Northstar a year or two ago.

In a correspondence with Northstar a few years ago, my contact there was very keen on Powermania for charging the Northstar. It is not a popular brand here on BBC, but, I have heard that it is better known in the saltwater crowd. The MK PC 10 or 15 amp/bank would be a good choice if you are already looking at MK.

I found the 40 amp Powermania Turbo on Amazon, https://www.amazon.com/Powermania-Tu...EK6QGHZGCCDYVC . Looks like a heck of a charger...fan cooled.

I'm wondering, since I only need a high amperage charger for one battery, why can't I just use my 25 amp bench "smart" charger which has the AMG setting. I'm not fishing much these days so having to hook up the clips each time wouldn't be too much hassle. I could continue to use my MK 5 amp, which charges my troller batteries just fine. I suppose the MK would still work fine with one of the leads disconnected.