I have a couple small questions about charging my trolling motor battery in my small boat. I recently bought the MAXX Everstart 29 series Deep Cycle battery from Wal-Mart and was wondering what the best setting on my charger is to charge a battery like this after I drain it. 2 amp, 4 amp or 6 amp?

My other question is after running my trolling motor ( A Minn Kota 27#) a few hours when I hook up my charger it apears amlost fully drained, should I be getting more life out of a battery like this? Was my mistake buying a battery from Wal-Mart?

Thanks ahead of time

Harshman

I've had no more problems with WalMart batteries than any other however it was my understanding that this is a starting battery, not a deep cycle suitable for trolling motors.   Starting batteries are designed to give a high current, eg. 1000 amps for a short time.  For trolling you don't need more than 50 amps but you need thick plates to hold up for a long time.

If it appears to be well discharged, use the 6 amp setting but it does depend on what kind of a charger you have.  It may need to be switched to a lower setting after being on charge for 24 hours if it is a "less intelligent" or older style charger.

Deep cyles like to be charged fast put it on 6amp and charge away. Does it have a shutoff.

Garnet

The charger I have is brand new with an automatic shut off. I'll recheck the battery when I get home but I'm positive I got a 29 series Beep Cycle battery, It is a great big battery compared to most starting batteries I have seen it is about 2-3 inches longer. Could be a starter though I guess, now you have me second guessing myself. That would explain the short run time however. Shouldn't a deep cycle battery be able to run this sixe of trolling motor for more than 3 hrs, with avarage use not full blast all the time???

Harshman

you might have bought a dual purpose. if it has cranking amps listed anywhere on it its a dual purpose or cranking battery. if its a deep cycle it should get you easily 8 hrs with a 27# motor. i have a walmart 27 battery not the max just the regular black one and it would go 8 hrs with easy on my old 30lb and even gos 8 hours on my powerdrive 55lb

First off I had to read and re read your question and then re read it word for word and then I THINK I got what you really ment.

You say that after using the TM a few hours then you hook up a charger it swings down to the 20- 30% and that is alarming you. I wouldnt go buy that swing as all my portable charges do that . You need to measure the voltage or get a hydrometer to test teh batteries.   A 10.00 digital volt meter would be a great choice. There is a chart for percent of charge. It goes like this.

12.65-12.75 100% full

12.55 90%

12.45 80%

12.35 70%

12.25 60%

12.15 50%

12.05 40%

11.95 30%

11.85 20%

You want to stay away from   de charging it under 30% as it will give you much less cycles recharges.

Speaking of  Recharging,, ANNE Can you jump in. What is the myth about needing a strong 10 amp+ charger to properly charge a big battery 29-31 series.  My son has a 2 bank 5-5 and it does fine on aset of MAXX Marine 29's??

That big Maxx Marine 29 is indeed a deep cycle and one of the better batteries for the  $$

The battery I bought was indeed a starting/deep cycle/RV battery so I am guessing that it needs to be returned for a true Deep Cycle battery.

Stratosdadri you were dead on inreading what I had put down. I will use your testing method in the future when I want to check the battery.

Thank You all for the advice

Harshman

Well first of you go have a deep cycle even true deep cycle will serve as a starting battery as long gas you dont have 200+ HP motor.

If you want the best get a Trojan scs 225  31 series or a AC Deloc Voyager which is sealed . Both will be in the $150 range.

You might have a bad battery.  I've had one of my G29 MAXX batteries for 3 years.  It isn't unusual for me to get 10-12 hours of runtime running a 30 lb. thrust TM.

If I'm out for 6-7 hours on an electric only lake, I'll usually have about 70% of the battery's capacity left.  Extra windy days spent running into the wind or keeping the boat in one position into the wind will drain a bit more.

The G29 MAXX is one of the best deals in batteries.  FWIW, it isn't manufactured by Wal Mart but by Exide.

Speaking of Recharging,, ANNE Can you jump in. What is the myth about needing a strong 10 amp+ charger to properly charge a big battery 29-31 series.

Anne may have more up to date information but this is the way I understand it.

Charge is measured in amp-hours. If you have more amps it will take fewer hours to charge and vice-versa. When you are discharging a battery, the total energy you get from it in amp-hours is the same but you lose voltage in the battery and the amount of loss increases with current. So batteries are less "efficient" or have a lower reserve as you draw higher currents. In theory the amp-hours in/out have to be identical but due to irregularities in the uniformity of the plates and electrolyte the capacity will diminish over life as some areas of the battery tend to take more load and other areas get underused.

This also applies to charging - the energy it takes to recharge at a high current will be greater due to heating and chemistry losses in the battery. The difference, however, is discharge amp-hours are precious while charging amp-hours are cheap and plentiful.

Older style lead-acid batteries used to benefit from an occasional fast charge and even an overcharge to stir up and de-stratify the liquid electrolyte however I don't think that applies to modern batteries.