I've read that lawnmower batteries are a good choice for powering side imaging units on small boats. I've used the Cabela's small 12v, but I want something with more longevity. 

My questions are:

1) will this power my Garmin 73sv?

2) how do I attach my unit to the terminals?

3) any videos?

I have thought about the same thing and I was just looking at the rechargeable 12 volt at Cabela's last week wondering how long it would work on a side view unit. How much run time do you get with it?

Thanks,

Kevin

12v is 12v................it will work just fine, and probably give longer life than the smaller 12v batteries used to power ice fishing/portable sonar units. You can clip the ends off you wires and re-crimp new ends on that will fit the terminals on the lawn mower/atv battery........pretty simple and easy.

12vdc is 12vdc, but be concerned with amp hour ratings. I would say that a lawnmower battery is built to start a mower then be recharged by the mowers alternator. It is not good to completely discharge this type of battery then recharge. A better choice would be a battery designed to be deeply discharged then fully recharged many times, like a power chair battery. I use two such batteries to power 2 HDS units at boat shows for 3 days with no problems.

4 minutes ago, eddallen said:

12vdc is 12vdc, but be concerned with amp hour ratings. I would say that a lawnmower battery is built to start a mower then be recharged by the mowers alternator. It is not good to completely discharge this type of battery then recharge. A better choice would be a battery designed to be deeply discharged then fully recharged many times, like a power chair battery. I use two such batteries to power 2 HDS units at boat shows for 3 days with no problems.

Power chair battery, that's a great idea! Which one do you use? Can you send some kind of link?

I picked mine up at Batteries+