Charging underway with 3 battery setup?

[davenrino]

My Brother has a fishing boat with a 150 Mercury OB. He currently has 2 12v group 24 AGM start/house batteries wired through a battery selector and charged from the OB, plus a group 31 dedicated stereo AGM that only charges on shore power. He would like to charge the stereo battery underway also. Would it be best to use a DC-DC charger or maybe an isolator with one input and 3 outputs (banks)?

[smac999]

Using an isolator doesn’t really work with outboards.

Why is he running a seperate stereo battery? Just make the house bank bigger.

Otherwise a dc to dc charger or acr will work.

[Uncle Bob]

Originally Posted by davenrino

My Brother has a fishing boat with a 150 Mercury OB. He currently has 2 12v group 24 AGM start/house batteries wired through a battery selector and charged from the OB, plus a group 31 dedicated stereo AGM that only charges on shore power. He would like to charge the stereo battery underway also. Would it be best to use a DC-DC charger or maybe an isolator with one input and 3 outputs (banks)?

Given the question I would simply go DC to DC charger.

[YANDINA]

The Combiner 100 was designed for this kind of application. No voltage drop, up to 100 amps charge, isolated when the outboard is not running and unlimited warranty.

[davenrino]

Originally Posted by smac999

Using an isolator doesn’t really work with outboards.


Why is that? I would think 60A alternator in an OB would be basically the same as an inboard.



Why is he running a seperate stereo battery? Just make the house bank bigger.


Tend to agree.


Otherwise a dc to dc charger or acr will work.

Thanks for the reply

[Ballsnall]

Just a a voltage sensing relay, cheap, effective and reliable.

[d design]

Why three banks?

[davenrino]

Originally Posted by YANDINA

The Combiner 100 was designed for this kind of application. No voltage drop, up to 100 amps charge, isolated when the outboard is not running and unlimited warranty.

Thanks. I like this idea.

[davenrino]

Originally Posted by Uncle Bob

Given the question I would simply go DC to DC charger.

Thanks

[smac999]

Originally Posted by davenrino

Why is that? I would think 60A alternator in an OB would be basically the same as an inboard.

Because it requires running a new cable from the alternator to the isolator. So new wire down the rigging tube, through the stern. Etc. hard on outboard. Easy on inboard.

[davenrino]

Originally Posted by smac999

Because it requires running a new cable from the alternator to the isolator. So new wire down the rigging tube, through the stern. Etc. hard on outboard. Easy on inboard.

Thanks

[OnePapillon]

Why not leave well enough alone. Guaranteed your brother's boat is on the hard or tied up most times. Surely he is not going to run the battery down playing music in one outing?

[davenrino]

Originally Posted by OnePapillon

Why not leave well enough alone. Guaranteed your brother's boat is on the hard or tied up most times. Surely he is not going to run the battery down playing music in one outing?

Actually, his fishing trips usually go a week or more away from charging and not always trolling. The 700w amp also draws some juice.

[davenrino]

Originally Posted by YANDINA

The Combiner 100 was designed for this kind of application. No voltage drop, up to 100 amps charge, isolated when the outboard is not running and unlimited warranty.

ORDERED!

[davenrino]

Thanks for the replies. Decided on a single start battery and 2 battery house bank connected by Combiner 100 and start power selected from battery switch.