I understand that the basic mercruiser charging system. I have 2 55amp alt. (twin 502). The batteries are connected through a battery switch (1,2,both). When both alt are running, I assume that the total amperage being introduced to the charging system is 110amp. Or, dose the regulators keep only 55amps being placed in to the batteries for charging?


I am in the process of installing 6000watt stereo. 4 1500watt battery bank. I do realize that these alt. are not going to be able to keep up with this, but i will be using it to assist in charging it when needed. I also have 50amp charger and geny. I was not able to find much for HO marine alternators.

I am thinking of installing another battery switch, connect 0awg cable to alt and run to this switch which would be used to charge the stereo battery bank.

I am interested in other ideas.

You should definately use a second battery switch. I would just run 1 Odyssey Group 31 off #2 on each switch and use them only for the stereo. With a Gen and charger, that should be enough.

Keep in mind the if the total amp rating of an Alternator is 55 amps, that rating is at a specified peak rpm. Meaning, about 2k or more. The amp rating at idle (750rpm) would probably be around a mere 20-25 amps. Poor quality product would be less. Don't forget the DC voltage produced either. That is a big factor on how the charging system is performing and the specific charging characteristics. Your battery type and size has particular charging needs. Make sure your charging system matches your battery needs.

I might have 2 280 amp alternators for the 496 "if" they won't work on the 500efi I'm willing to sell if not Ohio Generator builds High Output alternators

I've been to Ohio Gen site, but did not see anything on marine. Good to know that this is available.

Still wondering if I am running 2 55amp alt, does this give me a total of 110amp when switched to both, or is regulated to only produce 55amps?

I have been looking at the 1400 Kinetik batteries. 4 of them would give me 6000watt reserve. Price right now is 150.00ea. I have not found another AGM battery that totals 6000watts for 600.00.

I'm running 2 of the 2400 watt Kinetics great battery, but heavy they weigh 80lbs a piece. They convert your alternators and NO your 55amp won't keep up. You'll figure this out the first time your out.

I am not to worry about the alt keeping up actually. I usually run 15min to the our spot for the day. Spend all day partying and maybe and afternoon cruise 15-30min.

I have the Geny and 50amp charger that I will run. Don't know how long it will keep up.

If you were to run your system at 75%, about how long will it run before she drops into the 12V range? Assuming you are running around 4000-5000rms.

You can change to DELCO frame alt. and they can be built to over 180amp each,(i think) I still run the 55 amp and 3200 watts and mine has never dipped when they are running!!

never..