how many amps for onboard charger?

[cuzner]

I,ve decided to keep my boat in a marina this coming season. Figured I,d also add an onboard charger so I could cut down on clutter, and run as much as possible on 12v.Seen a good deal on a 10amp, 2 bank charger.any one know if this will be enough for cabin lights,stereo and occasional tv.Any input appreciated.<br /><br /> Jim

 

[Boatist]

Re: how many amps for onboard charger?

I seen many 13 inch picture tube CRT that draw 6 amps. A 100 watt light draws 8.3 amps. The stereo depends on the wattage. Bottom line running a couple of lights and even a small TV the charger will not keep up. However if you run the lights and a TV for a couple of hours and leave the charger connected after every thing is off it will catch up.<br /><br />I might try and find a deal on a little higher amp charger. Make sure it is a type that can remain connect with out battery damage. Most On Board chargers are fully automatic and can remain connected with out any damage.

 

[ThomWV]

Re: how many amps for onboard charger?

You haven't given anywhere near enough information to make a comment.<br /><br />Forget about what it is you want to power with a charger, concentrate on what the capacity of your batterys is. Find out what their storage capacity is (how many amp hours they can store) and then look for a charger that can put out about 10% of that total. So if you have two Group 27 batterys, which typically have a storage capacity of about 100 amp hours, their total is 200 amp hours and a battery charger who's total output (all legs added together) is about 20 amps would be about right. You could go as low as 5% but at that rate you will loose some battery life (very little).<br /><br />With the use you indicate you need to look for one thing on a charger as well. When you see the amperage that the thing puts out in the sales literature look for this too. Look for something that says that the charger is rated for its output level at "continous duty". What that means is that the charger can act as a power supply as much as dealing with the batterys.<br /><br />The thing with most cheap battery chargers is that they are just fine for charging a battery but if you have equipment running while its charging then it becomes a power supply. That means it has to run long periods of time, usually at its highest power output. That's something the cheap ones really weren't made for.<br /><br />Thom