Dead Battery - Ideas?

[4x15mph]

I went to take the boat out today and when I got to the storage place to pre-start the boat, I discovered that my battery was dead. Upon looking at my switches, it looks like I accidently left the bow light on for over 2 weeks.

I used my jump box and started the first engine without a problem. When I tried to start the second engine, it would barely have enough power to crank and it definitely would not start. I was able to still start the first engine so I find that odd...

Anyway, I brought the battery home and hooked it up to my Noco battery charger and the lights are flashing indicating an "error condition". In reading the manual, this can be due to the battery having too low of a charge and they recommend setting it up to charge as a 6v battery. This isn't working for me either

Any ideas? Did I wipe the battery out and do I need a new one? Is there a way to check this or is there something I can do to restore the battery? This is an Optima battery from 2012 so I hope it is still good.

 

[Andy S]

Sounds like you battery voltage might be to low. If you have volt meter measure your voltage, some chargers won't charge at 12v is the battery is below 10v.

What I have done in the past to solve this problem is to use jumper cable to connect the low battery to my running truck. It only took about 10 minutes or so to increase the charge enough on the bad battery so that my charger could finish the job.

 

[4x15mph]

I might be okay. I attached the jump box to the battery for awhile and now when I connect the noco charger, it is showing that it is charging.

@andy07sx230ho , thank you and I think you are confirming this. I should be good

 

[jetboater4life]

My car battery charger at home has a manual setting on it. For a few really dead batteries I have had to switch to that for a while before I can switch over to automatic mode.

 

[Bruce]

Is it a deep cycle battery or a starting battery?

Starting batteries are damaged any time they drop below 1.5 volts.

Deep cycle batteries are still damaged but less so.

 

[4x15mph]

Not sure. It is an Agm battery and the only battery on the boat

 

[TechRider]

Sounds like you are all set now.

What model NOCO do you have? Most chargers will not charge if a battery is below 7 volts in normal mode. NOCO has a mode called supply mode where it will just supply 13.6 volts and does not look for battery voltages. It is for batteries in your situation. I have the 26000 model and the instructions on how to use this mode are pasted below

Here is the section from the manual.

USING 13.6V SUPPLY MODE
The 13.6V SUPPLY mode is used for low voltage batteries, maintenance
charging or as a power supply for 12V batteries (14-230Ah).
In order to operate the 13.6V SUPPLY mode, the battery charger MUST NOT
be connected to the battery.
CAUTION. USE THIS MODE WITH CARE. BOTH THE SPARK PROOF AND
REVERSE POLARITY SAFETY FEATURES ARE DISABLED. PAY CLOSE
ATTENTION TO THE POLARITY. DO NOT ALLOW THE POSITIVE AND
NEGATIVE BATTERY CLAMP OR EYELET TERMINAL CONNECTORS TO
TOUCH OR CONNECT TO EACH OTHER AS THE BATTERY CHARGER
COULD GENERATE SPARKS. CHECK THE POLARITY OF THE BATTERY
TERMINALS BEFORE USING THIS MODE.
To operate the 13.6V SUPPLY mode, follow these steps:
1.) Confirm that the AC power plug is plugged into an electrical outlet, the
battery charger is NOT CONNECTED TO THE BATTERY and you have a 12V
battery. THIS MODE IS FOR 12V BATTERIES ONLY.
2.) Check the polarity of the battery terminals. Make sure you understand
which battery terminal is POSITIVE and which one is NEGATIVE.
3.) Without a battery attached, PRESS and HOLD the MODE button for three
(3) seconds until the Red LED illuminates, indicating the 13.6V SUPPLY mode
is initiated.
4.) PAYING CLOSE ATTENTION TO THE POLARITY (POSITIVE TO POSITIVE,
NEGATIVE TO NEGATIVE) attach the battery clamps or eyelet terminal
connectors to the battery, starting with the POSITIVE cable first (NEGATIVE
first, if a Positive Ground System).
5.) When finished, PRESS the MODE button one (1) time to exit the 13.6V
SUPPLY mode and return the battery charger to STANDBY mode.

WICKED SMART TIP
After using this mode for low voltage batteries, if the battery voltage is
still below 7.0VDC, repeat the steps above and try leaving the battery
charger in 13.6V SUPPLY for a longer period of time. If after twenty-four
(24) hours the battery voltage is still below 7.0VDC, you may have a
battery in poor condition.
Now That’s Smart, Wicked Smart.™

 

[Bruce]

Not sure. It is an Agm battery and the only battery on the boat

AGM batteries handle deep discharge better than deep cycle batteries. You should be fine.

 

[4x15mph]

@TechRider , I have the 3500 model noco charger. It does talk about using the 6v mode for a deeply discharged battery. This didn't work for me but using the jumpbox seemed to get the battery back to a voltage that my charger is now working with. I am at 25% charged....

 

[jdonalds]

Our boat would drain the battery in two weeks even with all switches off. We installed a battery switch and (as long as we remember) turn it off when pull the boat out of the water.

 

[4x15mph]

Can someone provide a quick summary of how to install the battery switch? I just need an on and off and currently I have a number of leads that attach to each of the battery posts. Thank you

 

[Bruce]

Buy a new lead to go from the battery to the switch. Connect it from the positive side of the battery to the input of the switch. Connect all of the wires that were on the positive post of the battery to output of the switch.

 

[4x15mph]

I was able to get the optima battery up to 6volts by connecting the battery to my jumpbox for an hour or 2. The Neco charger then took it up to 100% after it ran it through several phases (recovery mode) but this took at least 24 hours.

I brought the battery to the boat today and both engines fired right up.

I am still scratching my head on why the jump box would only start one engine while the other cranked slowly and would not start. Again, I proved that the jump box had enough amps since I could repeatedly start the one engine.

 

[Bruce]

[QUOTE="I am still scratching my head on why the jump box would only start one engine while the other cranked slowly and would not start. Again, I proved that the jump box had enough amps since I could repeatedly start the one engine.[/QUOTE]

Some theories would be;

1. The engine that would start has a starter that is less efficient (going out).
2. The engine that would not start has a fouled connection somewhere on its power or ground cabling reducing the amount of current available to it.
3. The engine that would not start is harder to turn over (I hope not).