I'll have led lights inside my kayak as well as outside. I'll have bow green and red led lights. I'll have a side view fish finder, a trolling motor and a camera.

I have no idea what a 27 or 31 battery is. I've read lithium is the way to go but what size? Also any recommendations on the best manufacturers would be nice. any help is appreciated. 

Group 27,  Group 31, etc refers to the physical size of the battery not the capacity or chemistry.  If you have a battery compartment that the battery must fit in then you may need to pay attention to the physical size.  Other than fitting where you want to put it those numbers do not matter.  Obviously,  large batteries can have  larger capacity but capacity is measured in amp hours (ah).  You also need to consider the voltage your trolling motor requires.  Is it a 12V or 24V?   The tolling motor is going to use far more power than the other stuff you mentioned.  I would think a 12V 100 ah battery would serve your purposes very well assuming you have a 12 volt trolling motor.   Lithium batteries (LifePo4) are much lighter and last a very long time before they have to be replaced.  If your trolling motor then you will need a 24V battery just for the trolling motor and a small 12 volt battery for everything else.

 

Personally,  I don't think the brand matters as long as they've established a reputation.  All of the batteries are made in China with the same LifePo4 cells.  I would buy one off Amazon that has a good price and a lot of positive reviews.  Some people want a battery that has bluetooth so they can connect to it with a phone and check the charge level.  If that's appealing to you then make sure you buy one with that feature.

I have been running 27, 29 and 31 size batts for decades. These may be too large and heavy for a kayak.

 

I have been thinking about switching up to newer battery types, but as yet have not made the leap. I think if I did they would have to be inside of a fire proof metal box.

I would tend to think that weight is a significant factor in a yak.  I'd definitely go with a lithium battery solely for that purpose.

 

Sorry I'm not much help on brand with those.  I use Duracell AGMs.

 

You'll need a lithium battery charger too if you don't already have one.

I'd go lithium 12v, 50-100ah, group size 24, 22, or mini. They're smaller and weighs a lot less. 

 

https://ipowerqueen.com/collections/12-series

 

Lots of options. 

4 hours ago, FloridaFishinFool said:

I have been thinking about switching up to newer battery types, but as yet have not made the leap. I think if I did they would have to be inside of a fire proof metal box.

Lithium Ion batteries have a reputation for going up in flames.   LifePo4 (Lithium Iron Phosphate) batteries are much safer.  

Having moved from that approximate setup to the boat just this year, I’ve been there.  I ran an 80 ah for the trolling motor and a 30 for the FF.  I was running a 9” helix plus FFS and the 30 was enough for a full day and then some.  If you’re only running a 7” SI unit, then a 10 ah Li will be close depending on how long you fish it (should get 6-8 hours).  For the price difference, just get a 25-30.  On the trolling motor, again, depends on how much you are running it and how hard.  The 45 lb thrust I was running drew 40 amps at full draw so I could run 2 hours at 4 mph before it would die.  Or, back the motor off a little, run at 3.8 mph where it was drawing around 25 A and run it for 3 hours.  In practice, I could fish some of the larger lakes around here across an 8 hour day and still have enough juice to get home.  Limit the time at full speed.  Or, if you plan on making big runs all the time or are in a lot of current then up the capacity to a 100 or even a 160.

 

I was using Amped outdoors in the kayak.  I went with LiTime in the boat.  The price on the LiTime was just too good.  I think I paid $200 for the 100 ah that I used for the electronics and $240 for the 50 AH 24V for the trolling motor.  That’s cheaper than AGM prices.  

Thanks a bunch y'all. With everyone's help I figured out what I'm going to get. I couldn't have done it without y'all. 

I'm going 150-200ah on the 12v trolling motor from Newport vessels. For the electronics I'm grabbing a 50 ah. I want to have extra on both so when I hit Dale Hollow and other large lakes I can stay out 12-15 hours. 

Tight Lines y'all!!!

11 hours ago, LokiDawg said:

Thanks a bunch y'all. With everyone's help I figured out what I'm going to get. I couldn't have done it without y'all. 

I'm going 150-200ah on the 12v trolling motor from Newport vessels. For the electronics I'm grabbing a 50 ah. I want to have extra on both so when I hit Dale Hollow and other large lakes I can stay out 12-15 hours. 

Tight Lines y'all!!!

 

The LiTime 165 AH with bluetooth monitoring for $350 would be a good starting point then.  And it is still group 31 size so a standard shape if you want to put it in a box or a defined space.  From there they jump to 200 AH but it is an odd profile.  They have a 50 AH that is tiny.  It's marketed for trolling motors but will do just fine on the FF.  Also, if you're ready to buy now, they are having prime day deals that are ~30% off most of their batteries. Look on their website and also on Amazon.

I saw that. Sadly, I won't be ready until Christmas. I'm saving as much as I can hoping to find stuff on sale then. 

Deep cycle marine LiFeP04 the top rated and most popular with bass boaters are Iconic and Dakota,  higher priced but you get good customer service!

Lot bass boaters use 2 50AH batteries in lieu of a 100AH battery.

Tom

 

The Dakota 100ah LifePo4 battery cost $795 and can be bought on Amazon.  Compare Dakota’s Amazon reviews to some of the $150 batteries they sell and I don’t think you’ll be buying a Dakota.

1 hour ago, Tennessee Boy said:

The Dakota 100ah LifePo4 battery cost $795 and can be bought on Amazon.  Compare Dakota’s Amazon reviews to some of the $150 batteries they sell and I don’t think you’ll be buying a Dakota.

 

reviews aside (reviews can be bought and also the only people reviewing are those who have some particular drive to review the product either really good or really bad), A dakota is about 3-5 the price of the Litime.  Will it last 3-5x as long?  Doubtful.  The Dakota warranty says that 11 years is the guaranteed maximum but then also says that 5-10 years is the normal lifespan with regular use.  The difference in those two is that 5-10 years is the 'works like normal' and up to 11 years allows for up to 70% degradation in the battery.  So practically speaking I have to think of them as 5-10 year batteries.  That means the LiTime has to last 2-4 years to hit break even cost.  I'm pretty confident it will do that.  Also, if you do try to make a warranty claim on the Dakota, you have to ship it back yourself.  They will reimburse the cost if something is wrong but actually getting someone that will ship it is the challenge.  Most shippers won't take it from a consumer as it is dangerous goods.  So all in, I'm with TB on this one.  That's where I put my money when the time came to it.

Premium brands that give great customer service are Impulse Lithium and Drewcraft Ionic Lithium.  Less expensive but still have relatively good reputations are LiTime and Power Queen batteries.