best way to use 2 batteries with switch

[MolarBoater]

Maybe think about getting more powerful batteries? Had constant problems with WalMart regular style batteries till went with the two big "Yellow" heavy duty higher amp etc batteries.

[PAX]

Originally Posted by Fishin' DC's

Initially, I would rotate between Batt1 on one trip and switch to Batt2 on the next trip. That worked until I started using the stereo more. My GPS/Sounder started flickering out due to power loss on one trip. My dealer said that maybe it was drawing too much power and to leave it on ALL, which I have done from then until now.

My thought, which is in no means based on anything remotely electrically sound, was that the power use would be pulled from both batteries equally, therefore leaving good reserves in both batteries instead of depleting one altogether and then switching over to the second. I have had no problems at all, so far, in leaving it on ALL. But, I haven't used the stereo as much (nervous of the power drain).

I experienced something very similar yesterday except that I have not installed any electronics yet on the boat. My stereo started to flicker, went to a different station and it appeared to be OK except that next thing I know I can't start the engine. Now I am confused though. I have a dealer intalled two battery set-up with the 1-2-ALL switch. If switch is on #1 am I charging battery #1 when running or battery #2? I would thing that I am both using #1 and charging #1.

Thanks,

[ILLOGICAL GGC]

switch 1 charges and drains battery 1 with engine off. switch 2 charges battery 2 and drains battery 2 when on. both switch position charges both batteries and allows both to drain from the load while the engine is off. too much drain in both position would deplete both batteries to not be able to crank the motor. that is why i plan to put either the combiner or a isolater like osprey
GGC

[Genelie]

Wow, so many good responces. Soooo peace of mind, I have 2 battery set up with a switchable battery switch. both are deep cycle. I run everything off the main, and use the 2nd for back up. I turn My battery swich off, when not in use. Some electronics are still on, due to direct wire to the battery. ( manufactery recomds that on some electronics.) I have only come across one dead battery, that was before I turned off the switch when not in use., other than that all is good, I too fish for lobster at night that requires the use of my floods, lights, still never need to use the 2nd battery. Well hope you firgure out what you need.