M
mike
- Jan 1, 1970
- 0
What's proper battery charge voltage??
I've been asked to design a shunt regulator for
a wind/solar powered system on a mountaintop at 5000 feet.
It's a 12V Sealed Lead-Acid battery system that is cooking
the batteries when the wind is high.
The wind generator has internal limiting, but it still lets
the batteries go over 15V.
The brute force solution is a shunt regulator that
holds down the volts and keeps the wind generator
from over-revving in high winds.
What's a good way to shunt 14.4V at 40 amps?
By the time it's derated for reliability, including for altitude, I need
over a KW worth of resistors.
My initial thought was to cut some resistors out of
sheet metal and blow a fan on them.
But maybe it's better to use nichrome and let it radiate
most of the heat. Pros? Cons?
It didn't take long to realize that I don't understand
the difference between fast charge and float charge.
I'd always used the rule of thumb that I could fast charge
lead acid batteries at 14.4V, but should use 13.6V for
continuous float charge. Given a particular chemical state,
state of charge, the battery shouldn't care, within limits,
whether it's been fast or slow charged???
Sounds like the right thing to do is measure the energy out
of the battery and replace it (+ some efficiency percentage)
at 14.4V then switch the charger to 13.6V.
That make sense? Increase battery life? Overkill?
mike
--
Bunch of stuff For Sale and Wanted at the link below.
laptops and parts Test Equipment
Honda CB-125S
TEK Sampling Sweep Plugin and RM564
Tek 2465 $800, ham radio, 30pS pulser
Tektronix Concept Books, spot welding head...
http://www.geocities.com/SiliconValley/Monitor/4710/
I've been asked to design a shunt regulator for
a wind/solar powered system on a mountaintop at 5000 feet.
It's a 12V Sealed Lead-Acid battery system that is cooking
the batteries when the wind is high.
The wind generator has internal limiting, but it still lets
the batteries go over 15V.
The brute force solution is a shunt regulator that
holds down the volts and keeps the wind generator
from over-revving in high winds.
What's a good way to shunt 14.4V at 40 amps?
By the time it's derated for reliability, including for altitude, I need
over a KW worth of resistors.
My initial thought was to cut some resistors out of
sheet metal and blow a fan on them.
But maybe it's better to use nichrome and let it radiate
most of the heat. Pros? Cons?
It didn't take long to realize that I don't understand
the difference between fast charge and float charge.
I'd always used the rule of thumb that I could fast charge
lead acid batteries at 14.4V, but should use 13.6V for
continuous float charge. Given a particular chemical state,
state of charge, the battery shouldn't care, within limits,
whether it's been fast or slow charged???
Sounds like the right thing to do is measure the energy out
of the battery and replace it (+ some efficiency percentage)
at 14.4V then switch the charger to 13.6V.
That make sense? Increase battery life? Overkill?
mike
--
Bunch of stuff For Sale and Wanted at the link below.
laptops and parts Test Equipment
Honda CB-125S
TEK Sampling Sweep Plugin and RM564
Tek 2465 $800, ham radio, 30pS pulser
Tektronix Concept Books, spot welding head...
http://www.geocities.com/SiliconValley/Monitor/4710/