Battery + Alternator Question.
 

Done tons of searching but still have a few questions. Finally have my stereo equipment now just working on the battery setup.

Amps jl-900/5 Arc 600.2 = 1700 watts Rms. (not huge by any means)
Motor: Black Scropian 5.7 with I believe 65 amp alt., no luck finding upgrade so far.


Going to use: Two deep cycle batteries probably around 160 ah's Total.

Question: Dont do a lot of sitting and listening to music so my question is will my alternator keep up to the stereo demand while running both batteries in pararell with no isolation. (starting + 2nd batt wired together as one.)

May get perko switch if its better but most likely an onboard charger. Will I need a dual charger with the 2 batteries wired with no isolation or just a single as it acts as one big battery. Now how about if I install a perko switch? From reading it seems like perko to off postion and 2 bank charger to each battery when charging?

Sorry im very new to this and what ive learned this far is from searching, so please be patient.

I had 230 amp-hrs with my first boat with the same engine. My system was a little bit more powerfull, and I could play music, pretty loud for 5 hrs straight.

I would isolate the two battery banks (starting and radio batts) especially if they are different model or even age. I guess you can use a relay type isolator, or diode type. A perko switch is fine but relies on you, so if you forget in the wrong position you might get issues starting or else.

I tried to get a bigger alt just to be on the safe side, but could not find a delco 7si going over 70amps. I even tried to get it tweeked at a local shop and no of his suppliers could get him parts to upgrade it.

Thanks for the reply. Did a bit more reading and will go with the promariner 20 amp dual charger and perko type switch.

Right now I have a group 24 75Ah deepcycle/starting battery in the factory location. (Can not fit a bigger battery) Can I pair this with a group 27 same type isolated with perko switch and still run in "all" while running the boat and charge both batteries being different sizes. Gets very confusing reading different posts and getting different opinions.

I'm not an expert, but I would say yes, you can do it.

Pairing up batteries is an issue when engine is off with no isolator and no charger, since weaker battery will discharge the other one.

Also, I was advised not to pair up different kinds (ie 6v Vs 12v, AGM vs flooded and so forth...) and this at all times.

I like the relay isolator, it's trouble free. When you turn off the engine, your starting baterry is isolated automatically. No need to access the perko every time to change position.