Subject: generator 2 of 7



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(3540)   Sun 21 Jul 91 23:24                             
By: Don Kulha
To: All

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Voltage Regulation
Voltage regulation only is OK for batteries that are very shallowly 
cycled.  In shallow cycle service the battery refills almost 
immediately 
since it has only had a small amount of its energy removed.  In deep 
cycle service the batteries have had about 80% of their energy 
removed 
before recharging.  If deep cycle batteries are recharged from a 
source that is voltage regulated, they will be charged at the total 
output current of the source as it struggles to bring the batteries 
immediately to the set voltage limit.  If the charging source has 
say 55 amperes available, then it will charge the batteries at this 
55 amp. rate.  If the battery is a 100 ampere-hour battery, then 
the C/10 rate for this battery is 10 amperes.  The 55 amperes from 
the source would recharge the 100 ampere-hour battery at a rate over 
five times faster than it should be charged.  This will result in 
premature battery failure, higher operating costs, and much lower 
system efficiency.

Constant Current
Constant current charging means that the batteries are recharged 
at a fixed amperage rate until they are full.  The voltage of the 
batteries is left unregulated until the batteries are full.  The 
rate of charge is usually between C/10 and C/20.  Constant current 
charging assures that the batteries are not charged too rapidly.  
Rates of charge greater than C/10 produce heat which can warp the 
heavier plates of the deep cycle batteries. Too rapid recharging 
wastes energy in heat, and gradually ruins the batteries.

Solar Cells and Wind Machines
It is easy not to put up enough wind or solar to do the job.  Wind 
and solar sources are currently expensive enough that the tendency 
is not to buy enough power to adequately run the system and recharge 
the batteries.  If you are running stand alone wind or solar sources 
be sure that they can deliver at least a C/20 rate to your 
batteries.  
Wind and solar systems also need a motorized backup to provide 
constant, 
on demand, power for equalizing charges.

Motorized Powerplants
The motorized plant is reliable, high in power, and relatively cheap 
to purchase.  The motorized source has the distinct advantages of 
delivering large amounts of power when you need it.  This is very 
different from wind and solar systems, where you have to take it 
when you can get it.  Its major disadvantage is that it requires 
fuel.  Motorized sources do not usually suffer from being 
undersized.  
If the power source is capable of delivering between C/20 and C/10 
rates of charge to the batteries, then the system is happy.

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