Probably prorated over that time, and for the cost, they will certainly want to test it for issues.  Nobody is gonna just swap it for a new one !!

1 hour ago, gimruis said:

I assume that most of these lithium marine batteries have a 10 year warranty, don't they?  Could a guy buy one, use it for 5-8 years, and then just return it for a new one?  I feel like there's a bit of a loop hole here.

The few I have researched before I bought Ionic they were replace xx years or repair then prorate.  Not all but some.  Some are even pushing past 10 years.  Read that warranty carefully to know the ins and outs of it.

i run dakota lithium on my all electric boat. thats 5k worth of batteries but for the loss in weight and gain in speed its worth it. they run way longer than lead acid and last for more years. i have a battery shunt that gives an exact readout of remaining amp hours current draw etc. i also have the bluetooth app on my phone. the price tag hurts but i would never go back to lead acid.

1 hour ago, padon said:

they run way longer than lead acid and last for more years

I don't think anyone would argue that.  The warranty alone on most of them is an indicator that they are going to last longer.

 

My last lead acid batteries lasted 4.5 seasons.  That's pretty ridiculous for about a $100 battery.  The advantage that a lithium battery has over a standard one is the weight.  The longevity based on the price tag isn't worth it yet.  If I'm going to pay 3 or 4 times the cost up front, I would expect to get 3 or 4 times the life out of it, and that's not the case right now.  They will need to drop in up front cost to make it worth while solely from a simple math perspective (and I think they eventually will).

Don’t forget the zero maintenance factor.  

5 minutes ago, GaryH said:

Don’t forget the zero maintenance factor.  

You mean no water needing to be added? Gels and AGMs have that.

1 hour ago, gimruis said:

I don't think anyone would argue that.  The warranty alone on most of them is an indicator that they are going to last longer.

 

My last lead acid batteries lasted 4.5 seasons.  That's pretty ridiculous for about a $100 battery.  The advantage that a lithium battery has over a standard one is the weight.  The longevity based on the price tag isn't worth it yet.  If I'm going to pay 3 or 4 times the cost up front, I would expect to get 3 or 4 times the life out of it, and that's not the case right now.  They will need to drop in up front cost to make it worth while solely from a simple math perspective (and I think they eventually will).

Most reputable Lithium battery companies have warranties that cover exactly what you are asking, pretty sure conventional battery companies are nowhere near that.  You also have to consider the AH rating is more than you would get with a conventional rated the same AH since you have 80-90% capacity usage.  

23 hours ago, flyfisher said:

Most reputable Lithium battery companies have warranties that cover exactly what you are asking, pretty sure conventional battery companies are nowhere near that.  You also have to consider the AH rating is more than you would get with a conventional rated the same AH since you have 80-90% capacity usage.  

true.also my dakota rep told me on my trolling motor battery that they are warrantied based on cycles. Meaning how many times you charge and discharge. so he said dont charge it unless you need to. so I fished for 2 months without charging and still had 50% charge left. on a standard boat lead acid can still be viable due to price buy on all electric boats like i am forced to use lithium is a huge advantage if you can afford it.

22 hours ago, padon said:

true.also my dakota rep told me on my trolling motor battery that they are warrantied based on cycles. Meaning how many times you charge and discharge. so he said dont charge it unless you need to. so I fished for 2 months without charging and still had 50% charge left. on a standard boat lead acid can still be viable due to price buy on all electric boats like i am forced to use lithium is a huge advantage if you can afford it.

That's interesting on the cycles warranty deal because I have not heard that and it would probably extend the battery warranty even longer.  I fish from a kayak so the extended use of lithium combined with weight savings makes a difference for me.  

22 hours ago, padon said:

on a standard boat lead acid can still be viable due to price buy on all electric boats like i am forced to use lithium is a huge advantage if you can afford it.

If I was in a kayak, I would definitely consider a lithium.  Makes sense purely from a weight stand point.

1 hour ago, gimruis said:

If I was in a kayak, I would definitely consider a lithium.  Makes sense purely from a weight stand point.

I gained 0.6 mph (3.1-3.7 mph) on my trolling motor just by switching from a lead acid to lithium.  Under the right conditions, I can even crack 4 mph.  That, and the kayak is easier to balance, I only needed half the size of the battery (because I can use up to 90% instead of 50%), and it's easier to load/unload (12lbs vs. 65lbs).  

 

A hidden perk is that the lithium batteries output between 13.6-12.0 volts, instead of 12.6-11.3 volts.  And they maintain the higher voltage longer.  So not only does it remove weight, but it increases the speed of the trolling motor, and maintains the speed longer.