If i have a boat with two batteries should i start it with 1,2,or both. when is the proper time to switch?

Question

between them and for what reasons

Answer 1

Given that both batteries are fully charged, Start with Number one.  When you stop for lunch or something switch over to number two.  Never switch while the engine is running as that can damage the switch (or so the switch manufacturer says).

If you are going to run the boat for over an hour you can use both as both batteries will charge.

I used to have a dedicated starting battery as number one and the second battery was used for on-board power.  After a overnight trip I would run back home on two batteries to charge the house battery.

Caring for your batteries will make the difference between a good time boating to an expensive tow.

Answer 2

Turn to both and use it as both charge equal> Don't switch when running or alt damage could incur>

Answer 3

Try with one battery first .if that battery is not charged enough to do the job the try the second battery ,if that fails to the switch to both batteries . If it stars your half way home, run your engine on both batteries so they will charge.This way you will find out witch battery is taking a charge or not.

Answer 4

Is the 2nd battery a deep cycle "house" battery, to run your devices?

Is your engine's alternator output enough to charge both batteries?

Is it a "make before break" switch (as opposed to "break before make")?

If the answer to all of these questions is "yes", then crank the engine with #1 (assuming that's the cranking batt), then switch to "both" to charge both batteries.

I'd need to know more about the boat's wiring to tell you where the switch should be with the engine off and accessories on.

Answer 5

I have a similiar boat with the same setup.  Normally, I start with just one batttery but use both if hard starting.  I set mine up so that number one goes to the engine for starting and number two goes for all the accessory stuff.  This way I can drain number two dead and still have starting power on number one to recharge number two and get home.