My cranking battery is about 9 months old. It has not given me problems, but everytime I plug my charger in it needs to be charged. My trolling motor batteries will hit the red led's and within 30 seconds they go green, but the cranking battery will charge for 2 hours or more. I charged all the batteries Sunday night when I got home, unplugged them Monday morning. I plugged in the charger just a little bit ago to see what the cranking battery would do and it had three red led's on and the trolling batteries went to green immediately. I think I should take the cranking battery back before it hoses me, what do ya'll think?

On board charger? What brand? I got rid of my Minn Kota 3 bank on board because I replaced it under warranty five different times due to the banks going bad.

I now just use a couple of Sears chargers. They have a switch to go between conventional low maintenance (starter) batteries and deep cycle batteries. I don't know what the charger does different between the two types but obviously there is some difference or else no need for the switch.

I occasionally charge the starter battery but it usually doesn't need it. The only time it does is when I drop the tm and fish all day without cranking the starter battery much. Then the lights and electronics drain the starter battery but that is not often.

Your key phrase above is "it has not given me problems" I had to replace Interstate trolling motor batteries once under warranty and then just gave up and bought Trojans because the interstates wouldn't give me a whole day out of the TM. But... my starter battery is still the original interstate from May 2004 and I haven't had a problem with it and don't plan to change it till I do. So if you are not having problems, why change?

FM

Thanks FMNitro, That is kinda my feeling too. I ran it all day Saturday with my electronics running and it never missed a beat. I just didn't run the livewell pumps all day. The charger is a dual pro three bank charger. I don't think I will do anything till it shows signs of having problems.

Fishn_man, if it's a flooded cell battery, check the water level. Fill just to the bottom of the fill tube with distilled (only) water. Put a full charge on it then let it cool 2-3 hrs min. Check the specific gravity of each cell. If it's less than 1275 or 1.275, depending on your hydrometer, replace it. Also it's good practice to charge with the lid to your battery compartment open. Heat is another factor that will keep a battery from taking a complete charge.

With proper care and maintenance, it's not unusual to get 3-4 years of good service out of your batteries.


Good Luck!

Well, no one mentioned the fact that your big motor alternator may or may not be charging while you are running. Check the battery voltage while the engine is running. It should be at least 13.5 Volts or more. If it is not, then check the output of the alternator with an AC volt setting on your meter. If that is at least 113 to 14 Volts. If it is OK, then check the diode bridge or have it checked out. Marbravo

Good point, marbravo.

I checked the alternator and it was putting out 14 volts, should be fine. I need to check with the hydrometer, I'll do that tonight.

How about some accessory left on, ie: box lights, bilge pump, or ???????

All test show that the battery appears to be good. I think something may be wrong with the chargers assessment of the battery, but it does kick off after charging is complete. I guess it could boil the battery and ruin it though.

If you have enough lead length, swap and put your cranking battery on another bank and see if you get the same results from the charger.

Was the water level below the top of the plates?

Are you using a group 24 vs a group 27 for your cranking? It may be that between cranking, livewells, electronics, etc., you're drawing a smaller battery down further than the TM batteries.

I have a 2 bank Dual Pro (2x15 amp) in mine, and at times it will charge one battery longer than the other, up to a couple of hours. No pattern and no reason one should be lower than the other. Haven't played with it enough to see if it's a heat thing or what.

Tx Champ,
I don't have enough length to swap unfortunetly.
I have a 203 and the trolling batteries are in one compartment and the cranking and charger are in another compartment.

All my batteries are the 31 series batteries.

Yes, that water levels were good in all batteries. I usually check that monthly, especially in the heat of the summer.

Since my charger seems to charge them up good, I'm thinking I'll get through the rest of this tournament season then send the charger in for a checkup or repair.

Sounds like a plan! There are quite a few 203 owners over on the ChampioN owners board at BBC. One of them may can shed some light.

My Pro-Mariner Tournament Pro 150 has inline fuses on each bank for overcharge protection, in case something goes wrong with the charger the fuses will pop to protect the batteries.
I would suggest a cell check or hydrometer of each cell, then unhook the on-board charger and plug in a 2 amp timer charger and charge it for about 6 hours, remove the charger and let it set for about twelve hours to allow the "surface charge" to dissapate, then check it with the hydrometer again. This will tell you if the battery is good or bad. Then you can isolate it to the on-board charger, or some unknown source of discharge in the boat.

Sorry, I'm late to the dance. Have you checked and seen if your battery has any drain put on it when not in use? I have seen and heard of this happening.
You said you are running all 31's. Are they all the same model battery? You could do a non scientific test and just change batteries after you charge them up when getting home. If the next time you go fishing the TEST battery is also down you surely have a slight short.
I think you might also find the same thing if you disconnect your negative wire from the starter battery and then touch it to the negative post. If you have a spark you have a short.

Just a thought.

Hydrometer say's the battery is good.

Allison, Yes they are all the same brand and I didn't even think of simply swapping batteries to test that way. I'm going to try the negative wire before swapping those heavy batteries from side to side. Sounds like another test for tonight.