I have a fishing boat with three deep cycle batteries and I have bought replacements every couple years because I think i'm not carign for them properly with charging in storage when not in use.

I bought a sears brand automatic charger to start over again, it's a model 200.71222 I tried charging by the manual on the 10 amp setting.
I put the charger on one battery and it instantly went to the far left and kept blinking the green charged light, not sure what that means, anyone know?

When i put the charger on the second battery it went to the right around the 10 setting and just stayed there for around 16 hours, what does that mean?

the third battery it started at the right near the 10 setting and then slowly came down to the left near the zero mark but never turned on the green light and it took around 16 hours to do that also,what does that mean?

I need advice also on how to maintain and care for my batteries ,this is a huge expensive waste.

 

Do you use a trolling motor a lot? How about a live well aerator? In short I guess I'm asking if you really need deep cycle batteries.
I use automotive batteries but I don't have a trolling motor, live well, or other loads which create a heavy drain. I just have the sounder/GPS & marine radio. Durning the "off season" (usually Dec.thru March) I make sure I charge the batteries at least once a month. I also remove them from the boat & store indoors.

You may find these sites of intrest: Deep Cycle Battery FAQ

Boat Batteries

Don Casey Quick Tip #5: Battery Care

 

yes i use a trolling motor alot and live well.

thanks for the links.

any idea what it means from my charger readings?

 

Sorry, I don't know what they mean. If you still have the owner's manual I suggest consulting it. If you don't have it you might be able to get a duplicate.

I use a charger I got from, believe it or not, Walmart. I forget the brand name but it has a "battery recondition" feature which does a nice job if you let the battery go completely dead or it gets sulfated.

 

Not sure exactly what batteries you have there but not all "deep cycle" batteries are created equally.
There are marine starting batteries that are modified to allow occasional deep discharging but if you do not need starting ability they will not last as long as true deep cycle batteries for continuous loads.

We discussed this here.

You need to make sure that you discharge the batteries fully each time you use them but being careful not to go below 10.5 volts.
Here is some good info on testing, charging and care of a deep cycle battery.

 

Thanks for the links, I have never heard that about deep cycle batteries before.

I have one dual purpose for starting the big motor and two deep cycle ones for the trolling motor and misc boat lights and horn. All say marine on them.

Why does it say marine on them if they are no good for boat applications?
I would like to have more power for the trolling motor for sure.
maybe i could just buy a car batery for use as a starting battery?

how much does the batterys cost from the pro battery place?

 

Re-reading my post I may not have explained it properly.

There are several battery manufacturers out there who put dozens of brand names on their batteries.
As I can not know exactly what titles mfrs are putting on their batteries I should have really said 'dual purpose" batteries rather than saying all "marine" batteries are meant for starting and deep cycle use.
If dual purpose batteries are cared for properly you should get a reasonable life on trolling motor use, only not quite as long as a true deep cycle.

It is possible that there is something you are doing to shorten your battery's life.
You could check the condition of your batteries with a volt meter to check the charge level and a hygrometer to test each individual cell.
Let us know what you get if you do this.

If you print the PDF from the Trojan link the voltage levels and hygrometer readings are there.
If you do test the batteries top off the charge on each one then let the battery sit for 24 hours before testing.
Write down the voltage levels for each battery and the hygrometer levels of each cell then compare these to the chart.

Not discharging the battery fully before recharging is a battery killer for lead acid deep cycle batteries.

Here is one type of tester but there are many styles available.
I had a dash mount in my boat that read in volts and % that just clipped on to whatever battery was in use.
What make and model are the batteries you are using?

Click image:

Image courtesy of cabellas.com

You will pay less for a battery because of the weakness of the CDN dollar right now.
A true deep cycle was $120,00 for a 27 series size but I was able to get a dual purpose marine for $85.00 at Walmart last year.
I know the life will be less but it turns out it really doesn't matter for me now.
I am selling my 16' fishing boat and downsizing to a freighter canoe and tried powering it with a small 30lb thrust electric trolling motor.
Turns out that if there is any kind of breeze the trolling motor is not nearly powerful enough to move the canoe and two people.
Instead I'm going to buy a four stroke 2 hp gas guzzler which run almost silently.

 

Thanks for the replys.
I'm pretty sure i'm not helping the life of my batteries by caring for them wrong but I have heard different tips ,like do not discharge too much because deep cycle batteries like to be charged often or charge once before storing and it will be fine through the winter.

I don't have a tester for the acid but after charging the volts were zero on one battery and 7.5 on the other two.

the starting battery is a starting type battery named stowaway 525 cranking amps, 450 cca,65 reserve type 24

the two others are dual purpose Exide Natilus marine batterys, 630 mca,130 minutes reserve type 24.

looks like I need new batteries doesn't it.

 

is that what you think too gregH ?
any other tips or recomendations ?

 

Well, your batteries are probably shot.

I personally like to read and follow the manufacturer's recommendations as opposed to well meaning people or sales types.
Not because they are all wrong, it is because you can not be sure who is right.
A major manufacturer will give you advice that will make their product work better and last longer.

The bit about only taking off a small portion of the charge applies specifically to starting batteries.......Lowering the voltage too much on these will damage them.
The reverse is true of deep cycle batteries.........That is why they call them "deep cycle".

I am not sure if you printed and read Grady's or the Trojan link.
The Trojan page is one of the better manufacturer use and care guides and the sooner you study it the sooner this will all become clear.
I printed this for use at work because there is enough reference info there to help look after a large assortment of very large and also very small deep cycle batteries.

If batteries are an expensive and important part of your recreation, buying and using a hygrometer will give you the most accurate measure of condition.
Your batteries are likely toast but putting them on a charger again and checking the cells may teach you something.
JUST MAKE SURE YOU USE EYE PROTECTION IF YOU DO!

 

thank you very much GregH