Once boat is near finished-let's talk the electrics

[OrangeQuest]

There is not a "TOPIC" area for this and a lot of talk inside builder's threads have been talking about this. It would be nice if there was a fast and easy way to find subjects about wiring and electrical without cluttering up builder threads about it. Electrical should be in a subject by itself-IMHO

Charging banks of batteries and good practices:

My boat has 6 x 12v batteries and 4 x onboard smart chargers - works just fine!
Go figure!

You went into detail how your system is hooked up and if I remember correctly, the outboard does not charge all 6 of those batteries. And, if I remember correctly again, you know how long you can troll before the trolling batteries need to be charged, shore powered charged? You are going to have to go into detail again. I am sure there are other gray-haired builders that don't remember the details either.

My OB has a 50 amp alternator (46 amps @ 1000 rpm).
The OB is connected to a 120 amp hr wet cell START battery.
I have a 240v AC - 12v DC smart charger connected to this battery.
I also have a 12v-12v DC smart charger between the START battery and the HOUSE batteries (2 x 120 amp hr AGMs in parallel).
I have a 12v DC - 32v DC smart charger between the HOUSE batteries and my TROLLING motor batteries (3 x 120 amp hr AGMs in series), with a master switch in between so that I can disconnect that circuit when the TROLLING motor batteries are being charged from mains power.
I have a 240v AC - 32v DC smart charger connected to the TROLLING motor batteries.

When on the shore I connect the two AC chargers to the mains power to keep everything charged and maintained on trickle charge.
When on the water the alternator charges the START battery, once that is fully charged the smart charger kicks in and charges the HOUSE batteries.
When they are fully charged the smart charger kicks in to charge the TROLLING motor batteries.

To date this system has worked well! We spend 80-90% of our time on the trolling motor with 3 x sounders/chartplotters running, and can fish for at least 3 days without needing additional charge. If things are getting a little low, I also carry a small gas powered generator/inverter with which I can top things up. At this stage I don't have solar top up!

Someone in another thread mentioned Sterling chargers. Just be wary - I have had three Sterling chargers fail on me, one while under warranty and two while not. I am now using Promariner mains chargers but I see Sterling have new model DC-DC chargers out.

I don't use voltage sensitive relays (VSRs) as I have seen or hear of 3 now that have burnt! Fire on a boat scares the hell out of me!

With 6 x batteries on board, I dream of lithium but the big $$$ involved in a change over keeps me at bay, at least until my AGMs pack it in!

[OrangeQuest]

You went into detail how your system is hooked up and if I remember correctly, the outboard does not charge all 6 of those batteries. And, if I remember correctly again, you know how long you can troll before the trolling batteries need to be charged, shore powered charged? You are going to have to go into detail again. I am sure there are other gray-haired builders that don't remember the details either.

My OB has a 50 amp alternator (46 amps @ 1000 rpm).
The OB is connected to a 120 amp hr wet cell START battery.
I have a 240v AC - 12v DC smart charger connected to this battery.
I also have a 12v-12v DC smart charger between the START battery and the HOUSE batteries (2 x 120 amp hr AGMs in parallel).
I have a 12v DC - 32v DC smart charger between the HOUSE batteries and my TROLLING motor batteries (3 x 120 amp hr AGMs in series), with a master switch in between so that I can disconnect that circuit when the TROLLING motor batteries are being charged from mains power.
I have a 240v AC - 32v DC smart charger connected to the TROLLING motor batteries.

When on the shore I connect the two AC chargers to the mains power to keep everything charged and maintained on trickle charge.
When on the water the alternator charges the START battery, once that is fully charged the smart charger kicks in and charges the HOUSE batteries.
When they are fully charged the smart charger kicks in to charge the TROLLING motor batteries.

To date this system has worked well! We spend 80-90% of our time on the trolling motor with 3 x sounders/chartplotters running, and can fish for at least 3 days without needing additional charge. If things are getting a little low, I also carry a small gas powered generator/inverter with which I can top things up. At this stage I don't have solar top up!

Someone in another thread mentioned Sterling chargers. Just be wary - I have had three Sterling chargers fail on me, one while under warranty and two while not. I am now using Promariner mains chargers but I see Sterling have new model DC-DC chargers out.

I don't use voltage sensitive relays (VSRs) as I have seen or hear of 3 now that have burnt! Fire on a boat scares the hell out of me!

With 6 x batteries on board, I dream of lithium but the big $$$ involved in a change over keeps me at bay, at least until my AGMs pack it in!

Your C ratng for charging your batteries is typ 10% of AH rating or 24 amps.

The dc-dc charger in your system is rated for how many amps?

If you used half of the current available from your alternators; you'd be using about 24 amps. This is ideal.

For my boat, my alternators are 32 amps, my current C rating is 9 amps and the house is 24v. My dc-dc charger is 15amps at 24v or 30 amps at 12v. This means a low battery on the house will pull 100% of alternator output. And until I make the battery bank the right size, I would be charging above the 9 amp C rating. My bank is undersized due to a battery shortage. I bought two and planned to add two and now can't get the same ones, so have to buy four new ones $$$.

Your system sounds like it would tax the alternators much less, but still plenty.

What dc-dc charger are you using between the start and the house?