GW 330 Express Battery Switch

[JoleGW33]

So Ive been reading about battery switches, got two switches on my boat (4 batteries, 2 starting and 2 house/acc), and how they are wired.

Based on the wiring diagrams of my 2003 GW 330 Express, the selector only "selects" between the two starting batteries, that is either batter 1, or battery or both, but the switch never interferes with the house/accessory batteries, these go through a separate main breaker.

So to my understanding, the house/accessory batteries are never connected to the starting batteries so if I deplete them (which I wont, or at least try not to) I wont have trouble starting my engines?

Here is the wiring diagram:

 

[HMBJack]

"So to my understanding, the house/accessory batteries are never connected to the starting batteries so if I deplete them (which I wont, or at least try not to) I wont have trouble starting my engines?"

In my opinion, yes, you will have trouble starting your engines.

My story:
On a overnight tuna trip a couple years ago, I shut down my engines at about 8 or 9pm and spent the night, 60 miles offshore. During the night, I had my AIS transponder on, occasional use of Radar during watch, plotter was on all night as was Nav. lights and fridge. In the morning at say 4:30am - my engines would not start! Ugh! I simply switched the battery switches to BOTH and they cranked right up.

The root cause in my case was the Fridge. It's the biggest consumer of electricity of the things I had "on". Next time, I will shut the fridge down for the night or simply run the generator all night (a bit noisy though for the guys trying to sleep). On another occasion, I left my boat at the yard for 2 days with no shore power and the fridge was left on. Same thing. Engine would not start. Again, I switched to BOTH and the F250's started right up.

So, on your 330, I'm thinking your house loads will reduce your ability to do an engine start. Easy to flip OFF your Fridge and easy to switch to BOTH on your battery switch (and of course promptly putting them back to 1 and 2 once started).

Other than the above, you could look into a house battery isolator. They work well but I have not installed one on my boat (no need to with the generator on board).

 

[wspitler]

On my 2007 330, the starboard battery switch provides power to the "house" load and starboard engine. I run a pair of group 31 deep cycles as bank #2 and a pair of starting batteries as bank #1. At night I use #2 bank as house batteries. We run the refrigerator and electronics all night with no issues. At night the starboard switch is selected to #2 and port switch is selected to #1. The #1 bank sits all night not connected to anything but the port engine, so it is ready for starting port engine if the #2 bank is dead due to refrigerator etc. If the # 2 bank is weak in the morning due to powering things all night, start port with #1 bank and then shift starboard to #1 bank and start starboard engine. I hesitate to use 1+2 since it reduces your redundancy and very weak batteries can drain the good ones if left connected together. I also have replaced all my night time lights, including anchor light with LEDs. Two good deep cycle batteries should run the refrigerator for several days. We usually only run the generator for AC power to run A/C, if its hot or to cook at night or for breakfast in the morning. Of course if the generator is on we charge the batteries.

 

[HMBJack]

Thank you Bill for sharing this.

I will give it a try on my next overnight.

Funny but like you - I own a 330 Express + a Scout Center Console (a 20' Sportfish) with a Yamaha 150.

 

[everwhom]

Interesting question. I checked my manual (or at least the one posted on the Grady Site for my year -- 2003) and it has the same diagram as yours. The diagram definitely shows 3 battery banks: 1 port motor starting battery, 1 starboard motor starting battery, and 1 house bank (2 batteries). However, that is now how my boat is actually wired. For one thing, my Guest Charge Pro charger (original I believe) can only charge 2 banks. And the wiring for the batteries itself (also original I believe) has 2 banks of 2 batteries, with each banks wired in parallel.

So it would appear that Grady changed the battery setup from 3 banks to 2, but didn't update the wiring diagram in the manual.

 

[JoleGW33]

Interesting, thanks to all for the replies, I will keep investigating!

I guess I will just run the gen a few hours a day when I have my fridge on to be safe.

BTW hows the drone inside the cabin while running your generator? I feel like mine is quite noisy, FP 4.2kw diesel.