Trojan Boat Forum

Hello all!

I've started to make this diagram to understand the electrical system of my boat. I have very little electrical experience so I wanted to make sure I do get this right . This is the proposed plan, in reality there are some things that I must change. (Currently I have my bilge pumps connected directly to the battery, I recently learned that I must connect them to the battery switch with the house battery, not the battery itself ) So please review my diagram to see if there is anything else i should modify/change. I also plan on buying an isolator so that I can charge both batteries while the engine is on. I still have to figure out how to set that up...

If you guys have any electrical diagrams that you have made before, please post them below!!

Thank you!

Leo, you can get a complete electrical diagram for your boat by writing to Don at Beacon Marine. He will need the VIN # from your boat. I ordered a set for my boat several years ago, and it has saved me countless hours trying to figure out how things were when my boat left the factory.

As for observations, you need to add your connection from the alternator to charge the batteries. You likely want some sort of isolation between the starting and house battery. You want to make sure your bilges ,and all circuits for that matter, are connected off the main DC panel and behind a fuse. You would not want to connect anything directly off the battery switch selector switch as if the circuit load became to high (stalled motor or short in this case) the wiring could catch on fire.

...Why would you want the battery chargers to charge the batteries while an engine is running? That's the job of an alternator. And with out ac voltage away from the slip, it wouldn't do you any good anyway. Spend your energy elsewhere on your projects.

Leo,
Here's the original wiring diagram for my F-26. it might give you an idea
Matt

Just taking a quick look I think you need to re-think your charging plan. You have the 110 V battery charger for you start battery and a solar charger for you house battery. I don't think that will be enough to keep up with the house bank. There are a large selection of chargers on the market today that can handle multiple banks of batteries. Also you should think about maybe a 20 amp charger, not 10, it's a little light for the load. Keep in mind to that the house and start batteries should be keep separate and only paralleled to provide more power to start the engine, not to provide more power to the house.

It's best to separate out the negatives and positives at their source in a diagram even if they are in the same cable as I suspect is what's going on in your diagram with respect to the charger, otherwise it looks like they are both connected together which is a no no. Personally I have never liked the use of battery selector switches on boats. They leave too much room for error and are the number one cause for dead starting batteries when trying to leave an anchorage. Keep the house battery and starting battery banks completely isolated, and use only "ON, OFF" battery switches to turn the circuits off when not needed. An "Emergency Start" solenoid joining the two banks together through a momentary toggle switch at the helm can be used if the start battery ever fails to start the engine. Yes you can use a battery isolator to charge the two banks while under way and maintain bank isolation but there is a charging down side to these unless you spend some extra cash and buy a unit that makes up for the voltage drop inherent to the diodes. In your diagram, you show several wires going to the battery terminals, you should minimize the wiring going to the batteries and connect to common bus bars or the battery side of the switch instead, ie; positive charge wires can go to the battery side of the switch rather than the battery terminal. Regardless of the switch position, the battery will charge. Your bilge pumps should hook up to the DC distribution panel but if that is not practical, again the back of the switch or bus bar is okay as long as the circuit is fused.

summer storm wrote:Just taking a quick look I think you need to re-think your charging plan. You have the 110 V battery charger for you start battery and a solar charger for you house battery. I don't think that will be enough to keep up with the house bank. There are a large selection of chargers on the market today that can handle multiple banks of batteries. Also you should think about maybe a 20 amp charger, not 10, it's a little light for the load. Keep in mind to that the house and start batteries should be keep separate and only paralleled to provide more power to start the engine, not to provide more power to the house.

Doug, he does have a two bank charger. Though I do agree that 10 amps is light, it really depends on the type of boating. Unless you require quicker charge/recovery times, ten amps is fine if you'll simply be tied up at your dock most of the time. At the dock, I'd be happy if it just put out 2 amps during the week if that's all it took to bring them back up by the weekend. I spend a lot of time on the hook so higher output is good for me as I want to charge as fast/much as I can when I run my generator for other stuff. One should also consider that cheaper chargers divide their max output evenly to each bank, so a cheaper 2 bank 10 amp charger would give you 5 amps max per bank whereas a more expensive charger will supply full output capability to just one bank if it needs to which is typically the case with the house bank.