Battery Amp Hours for dummies?

[jvwfd51]

I would like to separate my battery banks and have an Engine battery bank...and an House Battery bank to run all the electronics, inverter, etc.

My question is how do I determine how long I can run all of my electronics before the House Batteries will need recharging. Let me use an example. Say with all of my electronics and accessories on, I get a draw of 50amps. I have a deep cycle battery with a rating of....lets say....200 amp hours. How long can I draw that amount of juice?

And another question that comes to mind is if I was to add a second 200 amp hour deep cycle in parllel, will that change anything?

Obviously I am looking to get the most time I can for those long days on anchor in a cove relaxing. But on the other side of that...i don't want to buy an 8D battery if it will be overkill. I guess you could call it a little battery tutorial. Any help understanding would be awsome.

Thanks

 

[Barnacle_Bill]

Re: Battery Amp Hours for dummies?

Using your figures 200 divided by 50 = 4. Divide 4 by 2 (becuase a deep cycle battery is worthless when 50% depleted) = 2 hours of use. Adding another battery of the same type in parallel would double that. Always recharge immediately after every use to prolong the life of the battery.

 

[Silvertip]

Re: Battery Amp Hours for dummies?

The next question however, is how do you plan to recharge all those batteries? You won't get the job done with a 15 minute run back to the dock or ramp.

 

[Moody Blue]

Re: Battery Amp Hours for dummies?

200 AH
200 amps for 1 hour (200 x 1 = 200)
20 amps for 10 hours (20 x 10 = 200)
2 amps for 100 hours (2 x 100 = 200)

Those would be ideal theoretical numbers. Reality as pointed out by bhile would result in less useable time.

 

[flargin]

Re: Battery Amp Hours for dummies?

To silvertip's comments

200 AH @ 50% discharged = approximatly 12.5 hours @ 20 Amp charging (20% loss)