Trolling motor eating up battery power

[Northlander]

Hey guys. I have a 65# 24 volt Minkota with auto pilot and I also have the co pilot hooked up. My problem is I am going through juice quicker than I think I should be.

I checked the batteries with both a tester and my on board and regular chargers. Both batteries read full charge. Im only getting about 8 hours out of them. Granted the Minkota will be on anything from 4-9 all the time but shouldnt I get more out of this set up? I know I was before.

So is there anything in the trolling motor that could cause this decrease in battery life? I changed out my 40 amp in line breaker and the other one was fine but I thought maybe it was getting old. That didnt help.

So anyone have any advice or ideas? Its a sudden loss of power after about 6 hours.

[PerchJerker]

Sounds like you just tested the voltage? You should bring them to an auto parts store or battery store and have them load tested too. Since it's a 24 volt motor it only takes 1 weak battery (amps, not volts) to affect how the motor runs.

[Gissert]

Definately get them load tested. I had a similar problem on my diesel truck with 2 batteries.

One had a couple of pretty marginal cells, and when it got cold out it really showed up in weak starts. Both would show good charge and voltage, but when load tested one of them really faded fast.

[shamrock7]

Steve,

If you are up this way, stop in and we can check them. I would have to agree that you have a bad battery. The other possibility is that your motor is starting to go bad and is drawing to many amps. (Bearings going or something like that)

[Northlander]

Duh! I never thought to load test them. Ill bring them to Interstate and have them check them out. Thanks guys. I love this forum.

[Jeremy airjer W]

I didn't think you could "load test" a marine battery and get an accurate conclusion to the integrity of the battery?

[Northlander]

I dont know but Ill find out in the next 2 days from the boys at Interstate.

[BoxMN]

If you haven't yet, check the water level (if you can, not sure of those batteries, but friend in battery business said there is no such thing as a maintenance free battery...).

First thing we notice when water gets low is shorter run times. Good luck.

[upnorth]

You didn't say how old the batteries are? My experience is deep cycle batteries start to go somewhere around 3 to 4 years. I have them in the boat and the RV and that is about the time I replace them as the charge life seems to start dropping pretty good about that time.

[Northlander]

This is the second full summer with them. They are going in today to get a once over by the Interstate Pros.

[Northlander]

Well I think we found the problem. At least I hope it was this simple. Seems the batteries that I thought were only 2 seasons old were actually 4 plus. My starting batteries (reciept I looked at) are 2 years old. Therefore my deep cycle trolling motor batteries were only holding 1/2 capacity, on a load, of what they should even though on my battery chargers and tester they read full charge. Now I hope my on board charger is still doing what it should be after 4 seasons.

The 2 new batteries will get the old Northlander full day test tomorrow.

[muskyhunter57]

I did the same thing with my cranking battery last summer. No juice. Take it to the Intertstate battery guy in town complaining that I just bought the dang thing last summer. He looks it up says it's five years old...My Deep cycle was the recent purchase...needless to say I spent some money on a cranking battery.

[Jeremy airjer W]

Money well spent if it keeps you on the water!

[BoxMN]

Duct tape with the date on top of battery helps us keep track of age Hope that was the issue for you! I think I have a bad charger in our duck boat - it keeps popping the GFI, but when I use normal charger it does not... hopefully just connection or ground somewhere.

[Northlander]

Money well spent if it keeps you on the water!

For sure. Went 8 hours with no problem and plenty to spare the past 2 days out.

[SCONASOTAN]

Can I ask what size, make, and warranty you bought? I need to buy some trolling motor batteries and was at walmart and their 27 series Marine batteries only had a 1 year warranty. I didn't buy. What kind of warranty do the Interstate deep cells have??

[Northlander]

I got 2 of the Interstate SRM-27's. If I remember its a 1 year full warranty and a 2 year pro rated warranty after that.

[Eric Wettschreck]

Dude, you prolly already know this......but.....to help keep your new batteries (and older deep cycles also) in their best shape, drain them as close to dead as you can then charge them up.

Just tossing this out there for the guys that may not know. Starting batteries like to be charged and stay charged. Deep cycles like to be drained and slow/trickle charged back to full charge. Keeps them alive much longer.

Good to hear your on the water!!!!!

[Northlander]

Yup I run them all day then let the on board charger do its thing when I get home. I figure 4 years is a good time for batteries that get used as much as I use mine.

[gunflint]

Let's see, you thought that you had two year old batteries but they were actually 4 years old? You might want to start looking into the Centrum Silver. I suppose next you'll be forgetting where the crappie holes on Fish lake are.

[Northlander]

Hey goofy I was looking at a reciept because the place I got them at didnt punch the holes on top of the battery. Only way we found out what year they were was Interstae new the code on the side of the batteries.

No Centrum or Viagra needed here. Heck if Im going for 4 hours Im calling all the girls not my doctor.