How much can 1 battery run

[snake91876]

I just bought cc boat with a 1990 johnson gt150 on it. It has a livewell pump,
baitwell pump, and bilge pump, lights. I want to add a stereo, vhf radio and a garmin gps unit and lowrance fishfinder unit. With all that said i only have one battery. What would be the best way to run everything. Will everything run on that one and then just have a spare starting battery. I will be going offshore so i want to have my electronics right. Any input will be much appreciated.

 

[achris]

Re: How much can 1 battery run

Let's do some numbers

Livewell pump - 2.5 to 3 amps
Baitwell pump - about the same
Bilge pump - same again
Nav lights (Red, Green, White) - 1.5 to 2 amps.
Some deck lights? - 4 amps

So far we have about 14 amps, assuming you run them all together (bilge pump shouldn't be running too often, or you have other problems to think about )

VHF radio - in receive mode, about 0.5 amp
Garmin GPS - We'll be generous and let it have 0.75 amp (usually GPSs run about 0.2-0.5 amp)
Lowrance Echo sounder - (don't know the model; colour, B&W, LCD CRT, paper) let's again be generous - 2 amps

That gives us another total of 3 and a bit.

Stereo - Ah, the crystal ball is being called! NO IDEA!! What's the maximum output? Someone here a little while ago was trying to entertain boaters in New Zealand, from Florida!!! with a 400w unit. To me, that's just crazy (not to mention damned inconsiderate). That puppy sucked 30Amps! So, if you're a considerate and conservative soul, like my good self, you'll have something in the order of 8 watts.... Plenty loud enough... I can't have the volume full up on mine, hurts my delicate ears
So let's assume you have a unit that sucks 3 amps....

Grand total of about 20 amps.... But you probably won't have them all running at the same time, maybe... I hope.

Average boat battery usually about 70Ah, so you'll get about 3 hours with that lot going full on...

Personally, I like two ginormous batteries and a proper switching set up... Can't get out and push... You could however pull the lid of your white thing and pull start it... something I can't do....

If you're settling down for the night just switch one battery off, that way you know you have a good one to come home on.

HTH

Chris.........
(Have you checked that you can actually start your engine with the emergency rope if you need to?)

 

[Silvertip]

Re: How much can 1 battery run

If you are going offshore, you need a dual battery switch and as large a deep cycle "house" battery as you have room for. If you don't understand the concept of a dual battery switch then perhaps a VSR (voltage sensing relay) is a better choice. It is automatic but unless it has a COMBINE feature you cannot start the engine from the house battery. The house battery by the way would power all accessories leaving the starting battery strictly for engine starting and instrument duties.