Terrova 80 issues

[fredcs1209]

last June I bought a 2015 crestliner superhawk with terrova 80. When I first got it I was able to troll all day and get a top speed around 3.5mph. Earlier this year I have noticed I could only get about 3-4 hrs and top speed around 2.8. I took my batteries to auto shop to test batteries and they confirmed that I have a bad battery. I replaced them with 2 group 31 140 amp hour and 242 RC deep cycle batteries thinking this will solve my problems as old batteries are group 27's. Went out this weekend with new batteries and was still having issues. I dropped my unit to minnkota dealer to see if the unit is drawing enough amps. If they clear the unit, I am thinking that my on board charger is not charging my batties to 100%. I have a pro maniner 8 amp hour charger...

i also noticed that after running an hour or so i drop form 4 batteries to 2 on the indicator and if i dont use trolling motor for a little bit it goes back up. When I am checking i am making sure that the is powered off...

have any of you guys have any issues similar to this?

[rnnonmt]

Fred - Couple questions:

Did you charge your new batteries before heading out for the first time? I know it seems like a dumb question but T/S needs to start with the basics.

If not, get them on your charger overnight 24 hrs or so and measure the no load voltage from each battery. Lets see what you have for volts on each battery. They should be the same after a 24 hr period give or take a 10th of a volt. Im not familiar with your charger so I am uncertain if it gives you lighted indicators of a full charge or not for each battery.

If you have a significant voltage split between the two batteries you can either swap the output leads from your charger to the batteries and see if the voltage split is now on the opposite battery OR you can try charging your batteries from an external charger and try again.

If these are wet cells a better test would be from a battery hydrometer to read the specific gravity VS measuring volts.

It is also possible you have a new bad battery.

Let us know what you find.

[Ozark Bob]

Fred, from your info I would start with fully charging and reading a rested voltage from each battery(at least 12 hours off the charger). I would suspect your charger is the culprit but it could be a poor connection somewhere. Bob

[fredcs1209]

I had new batteries on charger for 5 days and the onboard charger stated batteries are good. The minnoka dealer stated that my terrova is good and has no eletrival issues. I was thinking of taking out the batteries and getting them tested at autozone as they will be able to tell me how charged they and use a 40 amp hour to really charge them vs my 8 amp hr one.... thanks for your input

[hnd]

btw, those indicators on the unit are junk. mine tells me its fully charged even when my batteries are near drained.

[wellpastcold]

The first step IMHO is to get a decent charger. Pro mariner is cheap crap. I have had a couple of them with pretty poor results. A voltmeter is an inexpensive tool that greatly simplifies troubleshooting battery issues. A voltmeter will tell you the voltage the charger is putting out as well as the voltage of the batteries. Without this info you are just guessing. Good luck.