Originally Posted by maxpower220
Batteries cost about $125, they last 4-5 yrs on avg in a boat. That's nothing. I have a battery tender and it works great. A $40 investment on a $125 battery almost doesn''t make sense, but a $100 investment on a $125 definitely doesn't make sense.
Boat use and equipment runs the gamut from buoy enthusiasts to families to hard charging wakeboarders.
I try to tailor my advice to whom is asking using the info given or assumed.
The above quote is more relevant for a non-radio, buoy boat, in warmish climate with a single battery.
OP, with no additional info as to how he uses the boat but he has x-15 in a cold climate in his sig. I assume he has two batteries, at least one amp, general family use which includes a mix of use underway and floating.
Two batteries is more than a trickle charger should be expected to handle, especially if batteries are put away less than charged which is very likely since people often pull then sit. Motoring back to the dock on most WI lakes is likely not sufficient to recharge.
Assumed $250 minimum is more than enough to support a $100 investment to protect and extend life in a cold climate like WI.
$125 is also a low battery assumption. Optima is very popular with a 31 agm closer to $200 each.
On the other end of the spectrum, 5 Kinetik 2400's on my boat could set a person back $1500 with different charging requirements yet.