Breaker switch operation batt 2 only - please confirm

[UCF007Knight]

2019 Ranger z185 -
So I confirmed the + cable on my breaker for the cranking battery is on post 1 for battery one (cranking), trolling motor battery (24v) is post 2, and com post is hooked up to power poles, + to engine, Basically it’s connected per the diagram.

I had issues with running my fish finder and it draining my cranking battery (2 year old optima blue top 750 CCA AGM battery ) while the breaker is in the on/run position. I had to use the jump feature to crank the big motor. This has happened twice when running fish finders for more than a few hours. I know Ranger has this switch but I think nitro and another boat company uses the same one.

Question- when in batt 2 only position, can you still trim your big motor and run fish finders, power poles, (all the things ran to the cranking battery? I still can, but it doesn’t seem like there is a difference between on/run versus battery 2 only. I would assume when the breaker is set to batt 2 only, my power poles, fish finder, key to big motor, dash accessories and all would not work. Only the trolling motor. See the image of the breaker type.

How does the breaker work for you guys when in on/run versus battery 2 only? Thanks in advance.

[mactlman]

switch not a breaker. allows the TM batteries to be used to jump start and turns off everything not wired directly to battery via a breaker --should be off when done on the lake and on when fishing

need a bigger and better battery likely a 31 series agm

[UCF007Knight]

When yours is set to bat2 only. What electrical devices still run on your boat ? How is it different than on/run position ?

[champ223]

Everything’s works on battery 2. It’s just pulling power from one of your trolling motor batteries instead of your cranking battery. The battery you have for cranking only has a 55AH rating. While it’s fine for starting the engine it doesn’t have a big capacity for running your electronics all day. Had the same with mine more so when I had to run livewell and electronics all day. If I was making a longer run I would use the jump start then put it on batt 1 for the run and the engine would charge it back up but it’ll still wear down after awhile. A larger battery will help you significantly

[UCF007Knight]

Thanks to both of you !!! @champ … you saved me a lot of further effort troubleshooting. Also appreciate the tips on how you use it with Bat 1 only to charge while running.

Thanks.