Is it OK to connect the Stern light to Crank Battery?

[Splash]

Just completed hooking up the Nav and stern lights on my boat.

When fishing at night and I am stationary, I understand I must have the stern light on at all times.

Is it OK to have this stern light connected to the crank battery without fear of flattening this battery?

Say, I fish for 4-5 hours at night with stern light on...


Splash

[Scalem]

Splash, while I am tempted to say it will be fine, for peace of mind I would leave the crank battery specifically for the motor and nothing else. There are a few variables that need to be considered. What quality are your batteries, and is the crank battery fully charged before you head out for a night fish? Are your lights L.E.D or globe? ( L.E.D use stuff all)

If you have not already, install a battery isolation switch and run 2 batteries, preferably marine batteries. Failing that, and if budget is a problem, any 12 volt battery will run your lights, grab something from battery allsorts or supercheap.

Scalem

[Moonlighter]

Assuming it is a LED light, you could run it for 4-5 days and still be OK! They draw so little power. So 4-5 hours will be fine. Although, i do agree that the seafest thing is ro run them off a separate battery, especially if you already run a dual battery system.

But on my last boat, i only had one battery, it was a good Supercharge Allrounder, and with LED lights I could easily run all night at anchor with no issues. Along with a cabin light and AMFM radio.

You refer to it as a "stern light". Actually, that is a misleading description.

The regs, assuming that where you live follows the COLREGS like here in Qld, require an "allround" white light to be displayed whilst at anchor at night.

Must be visible from all directions, 360 degrees. So it must be higher than anything else on the boat and be unobstructed. Can be challenging to do this on an open boat, usuually requires a fairly long light pole.

The old "stern light" concept, where a light is fixed to the transom facing rearwards, can be used as an alternative to the white allround, but only in combination with a second light that covers the remaining 180 degrees facing forward. Either way, a white light must be clearly visible and fully cover 360 degrees.

And, at anchor, the red/green nav lights are turned off. This way, other vessels know you are stationary.

A further comment. Many people think that the white allround light is only displayed at anchor. Wrong. It must also be displayed, along with the red and gren nav lights, whilst underway.

And, "underway" includes drifting. It is also a requirement that the white allround be located at least 1 meter higher than the nav lights.

All this is covered in the COLREGS. If any doubt, read them again.

[Splash]

Great response fellas - always good to be part of this forum and have enlightened views from the educated masses on all things boat and fishing!

I bought a telescopic "all-round" LED white light and it is pretty damn tall when fully extended.

I think I will buy a second 12V battery and park it beside the crank battery so that I can also affix all of my other stuff on it (sounders, etc..) - which are currently hooked up to the crank battery.

What is a good amp hour rating for this second 12V battery I should acquire to accommodate multiple devices, lights, etc?

Splash

[Moonlighter]

Splash, if you are going to change to a dual battery system, you might as well do it the best way.

And that is, without doubt, by installing a dual battery management system incorporating a VSR (voltage sensitive relay). They are quite simple and are very similar to the dual battery systems installed in many 4x4's these days.

The concept of this system is to have 1 battery dedicated as a starting battery only, and the other battery runs everything else on board, and is referred to as the "house" battery.

The 2 batteries are kept separate from each other by this system, but can be joined in an emergency (ie start battery fails) simply by switching one switch.

The system gives priority to charging the start battery, and when its full, automatically changes to charge the house battery. Simple and reliable.

This way, you run all your lights etc off the house battery, and it can never run down your starting battery.

Most people simply use a second battery same as their start battery. But you could also use one with a bit more reservae capacity such as the Supercharge Allrounders that I metioned earlier. The smallest one of them would be easily sufficient for most people in smaller boats like yours.

You can buy a ready to install system, complete with switches and VSR and east to connect. Mine is a BEP system, in fact this one:

http://www.chsmith.com.au/Products/B...with-DVSR.html

[Splash]

Many thanks Moonlighter.

Lots to read up on...

Splash

[Dignity]

Splash see if you cant put the second battery on the other side of the hull, you will find the extra weight of it sitting next to the current battery could put a lean on your boat and make it just that little bit more difficult in steerage.