I bought one of those cheap everstart marine deepcycle batteries at walmart a couple weeks ago, and have it hooked up to both my fish finder and trolling motor, Iv probably used it a total of 10 hours so far, with the fish finder always on, and normal usage of the trolling motor, how much juice do you think i have left?

You need to recharge it after every use, regardless of how much you've used it.

As Glenn said , charge it after every use.

I have used them for years. Both for starting, and two big deep cycle for my 24V trolling motor. If you keep them charged, they should last for 3-5 years.

The Everstart batteries that Walmart sells are the same manufacturer that makes Motorcraft for Ford, with different decals.

For a low price battery, they are decent.

I had one last 4 years with proper maintenance and care.

That's just about the same as asking how long as a tank of gas will last in your vehicle.

Tom Way2slow is right. There are many factors that determine how long a (any) battery will last. How far do you discharge it when fishing? How often do you do this? Do you charge it after each use? How do you charge it? Do you properly maintain that charge? Do you maintain the proper level of electrolyte? All batteries have a limited number of charge/discharge cycles. The more the battery is discharged per cycle, the less cycles available. It is capable of producing a finite amount of "power", and all of the above variables are part of the equation.

As others have said, treated properly your Everstart battery should serve you well.

FWIW there are a couple of "battery" threads in this forum that discuss these issues at length. They will help answer your question.

untill the warranty is done then you go back to walmart and get a new replacement lol

Well said Way 2 Slow