Cabin lights without shore power

[Vern]

I have a 2004 H260, stock in all electrical respects except I just upgraded to a Group 27 battery, which I assume is a single battery. I'm unable to get back to the compartment due to my size, unfortunately.

Without shore power, in my slip at the marina and with a full charge on my battery, how long should I be able to light two cabin lights without endangering the battery charge for starting my motor? I have checked the archives but I couldn't get the search words to match my question.

I don't know the battery manufacturer and the specs for the batteries listed on-line all seem to be different.

 

[Don S/V ILLusion]

there are all kinds of Gr 27 batteries and cabin lights

Obviously, it depends on how much current your lights draw, how long you have them on and what the capacity of your battery is. All Gr27 batteries are not created equally either. In other words, all you can hope to get with little info is a wide range of answers. More important, if it is the wrong type Gr27 starting battery rather than a depp cycle one, you have to also consider discharging it more than 5% can significantly shorten the battery life.

What is the current draw of the lights?
What type battery is it?
What is thge battery capacity?
How long do you expect to run the lights?

I'm sure lots of people will be happy to give you a good guess but any answer you get without this info is meaningless.

 

[Vern]

Don - Thanks for the reply

Initially, my question was given the worst case scenario, what is the best guess for how long I'd be safe running the lights.

After your reply, I think I'll dig up the bill for the work order and find out about the exact battery they installed. The marina I'm at knows how I use the boat and it's top-notch in the service department (in all departments, for that matter).

I will pay particular attention to the deep cycle aspect. Living my entire life in the frigid north country, I must admit I had no knowledge of deep cycle. In the "old days", we used to have to crank the car engines endlessly trying to get them started. We used to drain the battery down to within 5% of it's power rather than just down by 5%.

Thanks again.

 

[Don S/V ILLusion]

Vern

If I were to base an answer on only the cabin lights in my boat whioh burn around 1 amp and if I left them on for 6 hours, that's obviously 12 amps for two lights. If you have a typical auto 12V Gr27 start battery with a cap of somewhere around 90 amps, you have just used 13% - insert whatever numbers you think appropriate for your own calc.

That won't have much effect on the battery life if you do it infrequently and recharge it fully afterward.

If it's a deep cycle 90 amp battery, do the calc for the number of nights you anticipate going without recharging but consider that deep cycles should not be discharged below 50% capacity.

 

[Donalex]

Ampere Hours

Vern,
Electrical power consumption is measured in 'ampere hours' (Ah). This means the current (Amps) multiplied by the time (hours).
So two lights each drawing 1 amp means a total of 2 amps. Run for 10 hours will use 20Ah.
If your battery capacity is 90 Ah and you only run it down to 50% this means you have 45Ah available for your lights.
Thus 22.5 hours of usage at 2 amps gives 45 amp hours. So you should get 22.5 hours of lights before your battery is 50% discharged.
At 50% discharge your battery should still have plenty of energy left to start your engine.
It is best not to discharge more than 50% because this will shorten the battery life.

You are probably aware that most boats fit two batteries, one for the 'house' and the other just to start the engine. If you choose to go this route then the engine start battery can be really quite small.
The smart idea is to wire the switches so you can use either or both batteries to start the engine.

 

[George]

Battery

Vern:

The battery location for the H260 is the absolutely worse place to have a battery. It's on the wrong side and hard to service. Why not consider relocating it and adding an additional battery and charger?

I added a battery to my 2003 H260 and have plenty of power for a week of cabin power and have never had a problem with the starter battery.

Go to this link for more info: http://h260.com/electric/electric.html

 

[JungleJetJock]

mine

On my H260, being that is on a lake and has an outboard with a pull start option, I only have one battery. My boat never gets plugged in because I have a solar panel on the back. I have also replaced ALL of my lights but 1 light with LEDs. With the standard day we have in Texas I can leave all of my lights on continuously for probably about a week before I would have to plug in or start the motor to re-charge, although I don't know why I would (and this doesn't include using the stereo). The LEDs are great for power consumption but they are slightly dimmer than regular lights and, even though advertised as warm white, are a much cooler white than incandescent bulbs. They put out about the same color white as a florescent light. They use about 10% the Amps of what a normal bulb uses and will last practically forever before they burn out. With a solar panel added, even a relatively small one, your battery will get topped off without ever having to worry about plugging in.