Thomas Wentworth wrote:
I get so confused when it comes to electric power, especially battery
output. How many AMPs can a battery put out before the battery is
dead? Say, a 12 volt battery. Could you put this as .. "if you have
on a light for xxx hours the battery is gone".

I know AMPs are the flow of power and volts is the possible amount ..
measure of flow and time . and light bulb.

Why am I asking? I was looking at this boat on a web site and the
owner had added a bank of small batteries. About half the size of
the marine ones I'm use to. The batteries were tied together so they
became on big battery in power possibility.

Now,, if he had 6 batteries and each one is an 8 volt .. does this
mean he has 8x6 = 48 volts of possible power? And how does this work
out to amps. ?

batteries are heavy. how many do you carry. wouldn't a bunch be bad
for the boat??

also.. solar power.. how much power does one of those things give
you?

thanks,

The voltage has absolutely nothing to do with it. A 12-volt battery has a
stated capacity in amp/hours, and will last until exhausted when a 12-volt
load is applied. How big a load? You tell us!

If a battery's stated capacity is say, 100A/H, then a 5-amp bulb would in
theory burn for 100/5=20 hours, but in practice this is simply a guide,
since the bulb would go dim once the battery's voltage dropped below the
12-volts output, and in fact the bulb might still be showing some faint
light after 30 hours or more.

For the six batteries you mention to give 48 volts they would have to be
wired in series, i.e. each one positive to negative, whereas in parallel
(positive to positive and negative to negative) they would give you 12
volts, but the capacity would be the sum of the six batterys' capacities.

Space and layout permitting, It is better to have as big a battery as the
boat will permit for house use, and a starter battery appropriate to the
size of the engine installed, banks of batteries are fine until one packs
in, then you have to find the culprit and remove it from the bank. Auto
batteries are often used as the starter battery, whereas a slow discharge
battery is better for the house requirements. The 2 batteries can be wired
for charging purposes by a splitting diode or similar arrangement which
allows them both to be charged together, but discharged separately.

Amps = volume and volts = pressure, think of a hosepipe.