I just wanted to pass on a tip, that I have got a lot more miles out of my trolling motor batteries these last few years by on a regular basis checking the water level in my deep cells. I added water three weeks ago and yesterday needed to add more. Not a lot but some.
Honestly in the past I’d check the water levels about two – three months and every other cell would be low – slow learner i guess!!
I like the water level to cover the cell plate by i’d guess an 1/8 to 1/4″. Do not fill to the top!
Your standard 27 size will hold up very well by giving them love and adding distilled water, so you won’t need those 300.00 batteries, more power to ya if you got those gells.
Have a good week.
Turk