Battery Issue

[CTsalt12]

Hi Folks,

So I finished my first season with a trolling motor, and stored for the winter.  I have 2 Duracell group 31's wired to a ProMariner ProSport12 Dual bank charger.  My trolling motor battery charger was not plugged in after the season was over, because I store my boat outside and it's an high traffic area to have an extension cord. 

2 months later, I go to plug in my ProMariner charger to shore power to maintain the battery and I am getting errors on the charger.  The error code indicates one of three issues are occurring (I can send a pic but it will show the same thing):

1. reverse polarity
2. poor connections
3. battery too low to charge.

Since my connections from charger to batteries have not been touched and the boat has been sitting idle, I don't think 1 or 2 are an option.  Unless somehow the charger fuse blew?  I also visually checked the connections and they all appear solid, no corrosion or issues. 

Now, what to do next?  My first thought is that I need to refill the water levels of the battery with distilled water as recommended.  Could this cause the low battery error?  Note, the boat is in the northeast and we've had some really cold temperatures this year, not sure if that makes a difference.  It was right around 32 when I was trying to charge.

If I stored the battery when it was low to begin with, and it truly is too low to charge and water levels are normal, what can I do next?  Is the battery dead to rights?  I also understand I should take voltage numbers using a voltmeter. 

[doug mayer]

You need to find out what the voltage is in each battery at this time; you can do that with a multi-meter .  Also, put a battery tester on them--that will determine whether they will deliver power and maintain power for a time.  The gauge on the tester is good to bad--pretty simple. A local garage will have one, or auto-zone or napa will likely rent you one.  Just because connections look ok, doesn't necessarily mean they are ok; disconnect, clean and reconnect them.

If the batteries are too low to charge, then you need to discover what is draining them.  If one or both have a bad cell, then there are always new batteries.

[Capt. Bob]

I'm guessing these are lead/acid type deep cycle batteries correct?

Most modern (and even some older chargers) will re-charge completely discharged L/A types. Still, many modern smart chargers do not have the correct algorithms to bring a deeply discharged AGM or Gel type back. This may also be true for the L/A type. You may wish to call the charger manufacturer and confirm. Bringing the batteries into a warmer climate will help with recharging but that's why you have an on-board system so you don't have to remove them. 

Good luck.

[wingtime]

I have found that newer electronic battery chargers will not charge a battery that is totally flat. You can sometimes trick them into charging by hooking a known good battery in parallel.

In those NE cold temps I would recommend storing the batteries indoors when the boat is in winter storage. Or at least charge it once a month. (Dead batteries will freeze at 32 degrees)

You should not add water to a discharged battery unless it is so low the plates are exposed. If they are... you have another problem.

https://www.practical-sailor.com/blog/Boat-Battery-Winter-Storage-10697-1.html

[CTsalt12]

Thanks guys.

Based on the feedback, I'm going to take them inside, clean the connections to be totally sure, check the water levels, and take them to AutoZone to have them tested.  I'll grab a new multi meter when I'm there, I think mine bit the dust.  Capt bob-they are lead acid deep cycle, think these are the ones: https://www.batteriesplus.com/battery/marine-and-boat/deep-cycle/bci-group-31m/sli31mdc

I sure am happy that I got a warranty on these batteries, they're not cheap. 

Wingtime-to your comment below: "You should not add water to a discharged battery unless it is so low the plates are exposed. If they are... you have another problem."

Why not add water to a discharged battery?  Safe to say if the plates are exposed I have some kind of a leak, and that's my issue? 

With my onboard house and starting batteries, I've never had problems leaving them in the boat December-April.  I guess these big trolling motor batteries are a lot more sensitive.  I also think that unfortunately I stored them empty.  Seems I got all caught up with end of season winterization and forgot the simple step of plugging in my charger. 

[wingtime]

The electrolyte level will rise when you charge them, that why!

[CTsalt12]

The electrolyte level will rise when you charge them, that why!

Got it, roger that.

[boatnamesue]

I've experienced the same issue...battery charger indicating error.  After confirming appropriate water level in battery, the first time it happened I exchanged the same charger for a new one.  Hook it up, same error.  Mmmmm.  I hadn't noticed prior to exchanging chargers that after about 30secs when powered on and clamped to terminals, the charger would automatically switch from the setting I initially pushed (2-6amp) to a different setting (10a boost).  When it switched to the 10a boost is when the error light activated.  After reading the manual I learned that if the battery charge is too low for 2-6a charge setting it automatically changes to 10a boost, and when this occurs I can manually reset charger to 2-6a.  When I did this the charger functioned normally, and thus completed the charge.   

[CTsalt12]

I've experienced the same issue...battery charger indicating error.  After confirming appropriate water level in battery, the first time it happened I exchanged the same charger for a new one.  Hook it up, same error.  Mmmmm.  I hadn't noticed prior to exchanging chargers that after about 30secs when powered on and clamped to terminals, the charger would automatically switch from the setting I initially pushed (2-6amp) to a different setting (10a boost).  When it switched to the 10a boost is when the error light activated.  After reading the manual I learned that if the battery charge is too low for 2-6a charge setting it automatically changes to 10a boost, and when this occurs I can manually reset charger to 2-6a.  When I did this the charger functioned normally, and thus completed the charge.

Ah, I see.  Unfortunately I can't manually change any settings on my charger, it's all automated.  The manual says if it's too low: " have your battery charged out of the boat and have it load tested by your local battery dealer to insure optimum performance on the water".  I don't really understand why charging out of the boat would be any different than in boat, aside from temperature this time of year.  Are there different chargers I can use at a battery facility? 

[boatnamesue]

I've experienced the same issue...battery charger indicating error.  After confirming appropriate water level in battery, the first time it happened I exchanged the same charger for a new one.  Hook it up, same error.  Mmmmm.  I hadn't noticed prior to exchanging chargers that after about 30secs when powered on and clamped to terminals, the charger would automatically switch from the setting I initially pushed (2-6amp) to a different setting (10a boost).  When it switched to the 10a boost is when the error light activated.  After reading the manual I learned that if the battery charge is too low for 2-6a charge setting it automatically changes to 10a boost, and when this occurs I can manually reset charger to 2-6a.  When I did this the charger functioned normally, and thus completed the charge.

Ah, I see.  Unfortunately I can't manually change any settings on my charger, it's all automated.  The manual says if it's too low: " have your battery charged out of the boat and have it load tested by your local battery dealer to insure optimum performance on the water".  I don't really understand why charging out of the boat would be any different than in boat, aside from temperature this time of year.  Are there different chargers I can use at a battery facility?

Just guessing here....reading between the lines of what your manual is saying...it doesn't have the ability to charge a battery when the battery to be charged is below a particular voltage.   I suggest calling the manufacturer of your charger, tell them what your experiencing, ask why the charger will not charge.

[RickK]

My Optima charger won't charge a battery if it is below 2.5V I think (had that error) - put a good battery in parallel with the bad and put the charger on them for a day or so and it charged the both up.  The battery that was real low was still bad after that though.

[boatnamesue]

Got it ^^

[Capt. Bob]

My Optima charger won't charge a battery if it is below 2.5V I think (had that error) -

1.25V

Don't ask how I know.

[RickK]

My Optima charger won't charge a battery if it is below 2.5V I think (had that error) -

1.25V

Don't ask how I know.

Ahh, that was what it said

[CTsalt12]

I put the trolling motor battery in line with my house battery which is in good condition.  Still got the error for battery #2.  After about 5 hours plugged in, still an error and no charge.  I think I killed these batteries by leaving them in storage for the winter with no charge.  Lesson learned.  Next year they come inside and stay plugged in.   

Really glad I got a 12 month warranty on these from this batteries and bulbs store.  Its about a 40 minute drive from my home base but great store FYI.