36v Lithium

[rochesterbass]

I am researching replacing my trolling motor batteries (currently blue top AGM) with a single 36V lithium.
I fish the great lakes and St. Lawrence river frequently so I have more demand out of my system than most.
I was looking at single 36V 50 Ah battery but think that capacity will be too low.
I found another battery that is 36V 40 Ah where I would get 2 and I think that capacity is plenty.
Basically, in my head, I need at least 60-65 Ah to get to a point where I will never kill my batteries.

I have a phoenix 920 pro xp with a merc 250 2 stroke on it and run a 112 ultrex.

Any recommendations/options are greatly appreciated.

Thanks!

[DQM]

What size blue tops are you running? 27M, 31M, or 34M?

[Impulse Lithium]

I am researching replacing my trolling motor batteries (currently blue top AGM) with a single 36V lithium.
I fish the great lakes and St. Lawrence river frequently so I have more demand out of my system than most.
I was looking at single 36V 50 Ah battery but think that capacity will be too low.
I found another battery that is 36V 40 Ah where I would get 2 and I think that capacity is plenty.
Basically, in my head, I need at least 60-65 Ah to get to a point where I will never kill my batteries.

I have a phoenix 920 pro xp with a merc 250 2 stroke on it and run a 112 ultrex.

Any recommendations/options are greatly appreciated.

Thanks!

Check out our 36v-60Ah. https://www.impulselithium.com/produ...y-w-bluetooth/

[rochesterbass]

I have the 31M blue tops in there but there was an older Motorguide X5 installed when I bought the boat.
I'm going to try running the ultrex on the blue tops but I don't think they'll last as long as I'd want.

[rochesterbass]

Thanks for the link! I'll definitely check it out.

[DQM]

At least they are the big blue tops. 75ah when new. Optimas are good, just not very big, so you can probably reliably get 65ah out fo them and charge them back up immediately and not lose too much capacity over time, although you will lose some.

The problem is last last 30ah, or when you hit about use about 60% of the charge in the batteries, you are now below 12 volts and it becomes a diminishing return equation quickly. The last 40% of charge will go much faster, and get progressively faster, as it nears 10%, which is about as low as you should take them. Keeping them around 20% would be best.

LifePO4 batteries will keep you at near constant voltage, with a small drop off, all the way down to the bitter end. Once they hit 12volts, they are 90% used and they drop off quickly then.

So a 50ah LifePO4 should provide the same or even more total output for your trolling motor as the 31M bluetops. A 60ah will deliver more usable power and would be a good choice.

[codyr]

Impulse lithium is a top of the line product. I would definitely recommend them

[KandKKustomz]

twin 36 volt 40 ah with a run and gun charger or single 36 volt 60 ah with a run and gun. I would be happy to help you. Powerhouse lithium. Best lithiums on BBC with the best warranty. 15 years total 10 years no proration.

[rochesterbass]

Thank you, I will get ahold of you when I make up my mind.