Re: [A/S] batteries (again) was boondocking in the snow

[William Jacobs <bjacobs1@xxxxxxxxxxx>]

><I have always based my battery purchases on CCA's.
 
CCA is cold cranking amps.  This is a measurer of the internal 
resistance of the battery.  It is not a measure of the capacity of the 
battery.  It just tells how fast you can get the power out of the 
battery.  You can get 650 amps out of the battery for maybe 30 seconds.  
There is an induster test.
What we want is 10 amps forever.  Capacity of a battery is a function of 
how well we can turn lead and sulphuric acid in to water and another 
kind of lead.
    +                            -      
 PbO2 + 2 H2SO4+Pb  Discharge->  PbSO4 + 2H2O
                                        <- Charge
This is a related to how much active material is available. It deals 
with Faradays, moles, and coulmbs.   The more the better.
Notice that there is no O or H by it self.  Gassing is not suppose to happen
Discharging makes water.  Charging makes sulphuric acid.  This way, the 
specific gravity of the solution goes up when we charge.
In order to get a larger capacity we need to get more active 
ingredient.  All things being equal, the more a battery weighs the more 
capacity it will havb.  Get the biggest, heaviest battery you can put in 
the space.   A 6 volt golf cart battery weighs about 2 times as much as 
a deep cycle and has about 2 times the energy.
I use a standard car battery,  I use a #27 or a #24 if it will fit.  
They are not as well suited to RV life as a deep cycle but I never have 
deep cycles last more than 3 or 4 years and a car battery is guaranteed 
for 6 or 7 years.   I give up a little capacity for a longer service 
life.  The current draw om my RV is about 10 amp at max which is about 
60% of the draw of the truck headlights.  In freezing weather, you want 
active material.  I get one night of furnance out of the car battery. 
bill
25 ft Trade Wind in WV