Adding a small 500 Skar amp , boat only has 1 cranking battery. Adding second battery and switch , what type of battery to run stereo ? deep cycle ? crank etc ?

Thank you.

In most cases a deep cycle, but can go better
Which small amp?

A deep cycle battery is going to take the cycling better. For a switch you can use a high amp relay to separate the batteries when you shut the boat off. When you turn the key the batteries combine for charging. Ideally you'll switch the control wire in such a way to allow you to self jump start yourself and prevent batteries from being connected.

How about an add a battery kit with an automatic charging relay (ACR) too ?

with 4 of the 6.5 speakers they offer.



Going in a Cobalt 20 i picked up for this summer since my 31 will not be ready this spring.

The amp requires 8 awg wire and 60 amp fuse. If its not cranked up it will draw less juice.
Might need 2 deep cycle bats and agree an ACR is the way to go for recharge along with built in charger to complete it when on trailer. If you want a bat you can drain down to 10% without hurting and can handle all it would take would go with Lithium-Ion. The Li bat cost a much more and weight is much less

Your boat most likely comes with a 65 amp ALT

One deep cycle Interstate Group 31 is what I use. I have 2 Alpine PDX amps with a combined 1100 watts and it will last 4+ hrs at 3/4 volume.
I control the charging via my battery switches.

I have 4 gauge wire for power +/-. Wil put a fuse as well at battery ..





Thank y'all .

Im going to use 200 amp constant duty relay between the primary battery and the stereo battery with a on-off-momentary that will allow me to have the relay connect when the engine is running, no connection when engin is off and the momentary to allow me to jump the batteries together incase the starting battery is dead.

Install a basic Cole Hersee relay, and trigger it with your key switch. Dirt simple, inexpensive, and idiot proof. I have sold, and/or installed
hundreds of these over the years, and the plain just work. If you are worried about corrosion, they make a plasticized version too.

https://www.partdeal.com/wiring-elec...EaAs_xEALw_wcB

Steve