Quote Originally Posted by Snaggin Wagon View Post
Bought a new Lund 1775 last year. First time using it on Erie was yesterday. Have a minnkota Terrova. 120 Lb thrust 24 volt. Using group 27 interstate deep cycle batteries. Lasted about 3 to 4 hours trolling. Are the lithium ion batteries worth the investment? A pair of group 31’s will fit? Any thoughts?
Okay first you have to know what you have- a 24 volt Terrova is 80lb thrust with an amp draw at about 56 at full throttle. Also you have to figure out runtime vs what batteries you have. Your Interstate batteries have a RC at 160 min. If you're running at 7, that's 70% of max so .7 x 56 = 39 amp. Your rc is 160 so 160/39= 4.1hrs. So that's about exactly what you're observing in the real world.

Easy answer to your lithium question. Lithium batteries of the same amp hr run about twice as long as lead acids. They also give full voltage till almost fully discharged. Lead acids are considered dead at 50% discharge and give diminishing voltages. You may have noticed that you might troll at a 5 setting to get 1.2 mph but an hour later you have to turn it to 6 to maintain the same speed. That's the nature of lead acid batteries. Not so with lithium.

Also if you went to group 31lead acid they have a rc of 200 so 200/39 = 5.1. hrs.

I'll also give you the benefit of running a 112 lb thrust 36v motor- the 112 only has to be run at a 5 to attain the same speed as an 80 at 7. It's amp draw is slightly less at 52, so .5 x 51 is 25.5 using 160 rc group 27 that's 6.25 hrs of runtime and with 200 rc its 7.85 hrs of runtime. That's pretty significant and with comparable lithiums- it's double that.

Hope this helps