G
George Ghio
- Jan 1, 1970
- 0
What do I do about charging? Well not a lot really. You see, when you
correctly size a system for your load, being honest about the numbers,
you end up with a system that works as planned. I seldom need to run the
battery charger.
My philosophy on battery charging.
Yes it is important that you not let them remain at a low state of
charge for long periods, on the other hand they do not need to reach
100% charge every single day either. I will run the little generator to
charge my batteries if they drop to around 12 Volts (but like the fine
print says "Conditions Apply")
1) Condition: Batteries read 12 volts (or less) at four o'clock in the
afternoon.
2) Condition: I know the sun won't be out tomorrow.
3) Condition: I need to use the computer for several hours that night.
4) Condition: There will be three hours of Red Dwarf on TV that night.
It takes at least two of these conditions to warrant the running of the
generator. And even then it comes down to gut feeling.
And when it comes to charging the batteries I am not trying to bring
them up to 100%. I am doing what I call ''Maintenance Charging'' which
is to say that I only require that they be in the top twenty per cent of
their capacity.
Yes I know it sounds like it's too easy, but the thing is that when
I started with solar power there was almost no information other than
guess work and trial and error. My life with solar power is pretty easy
these days because of what I learned from two or three disastrous years
in the beginning.
So let's say it's 4:00pm and I check the battery voltage on the reg. The
voltage reads 12V. The weather forecast is for rain for the next two
days and I have a rather lengthy paper due and expect to be on the
computer for 5 or 6 hours.
So I make a decision. I will run the battery charger. The charger is a
35Amp alternator on a petrol motor. The regulator for this rig is a
large ceramic rheostat salvaged from a very old spot welder.
The battery charger actually puts out 30 Amps and 16-17 volts at max
engine rpm. The tank holds enough fuel to run for approx. 3.5 hours when
filled to the top.
Usually around three hours of runtime will bring my batteries up to 15
volts. On some occasions I will turn the rheo down and wait for the
batteries to come back up to 15V. I may do this a couple of times, this
is of course dependent on what the voltage was at 4:00pm and what I know
about the voltage and the temp. for the last several days.
The numbers? Well, they mostly look after themselves. After nearly
twenty years of doing this sort of thing I really don't look at the
numbers any more. The reg likes to tell me that the batteries are at
100% charge. I sometimes think that it is not very honest for a little
black box.
Probably the most important thing to remember is that all the readings
are taken from a running system. As such the readings are not a true and
correct voltage reading. I do not rest the batteries, nor do I take into
account any voltage drop associated with what may be running at the time.
When the batteries read fifteen volts and I shut off the charger, I know
that if there is no load from this point on, the batteries will read
12.7 volts in the morning. What a surprise 12.7 volts is just what a
fully charged 12 volt battery should be.
Do I recommend this for everyone with a solar power system? NO!
Absolutely not.
Unless you are prepared to watch the voltage while charging you would be
best advised to use an automatic charger.
When I next run the charger I will make note of what the regulator is
telling me and relate it in this group. Don't hold your breath. I have
no control of the weather. At the moment we are in a cycle of cold
frosty mornings and cool to cold sunny days. Ideal weather for
photovoltaics.
Wayne says that I don't run my charger enough.
"Truth is the inquiring minds food, but is often bitter to the taste.
Most people prefer the savoury lie"
An example
Sunday, June 11, 2006. Voltage readings from my regulator. Overcast day
with periods of sun. Note voltage readings for 11 and 12AM as sun breaks
through.
10AM - 12.3V
11AM - 13 - 13.5V
12AM - 13.7 - 13.9V
1PM - 12.9V
2PM - 14V
3PM - 12.9V
4PM - 12.7V
This is the truth of my system. Wayne finds it bitter so he creates a
savoury lie that makes him feel good.
But as can be seen, 4:00PM and the batteries are at 12.7V. Yes, this
reading is not the true and correct voltage of the batteries. But, after
nearly twenty years of life with batteries I know that this is high
enough not to place my batteries in stress.
By far, most of the people who post here prefer the savoury lie and
there are many who are willing to support the lies because they also
want to feel good about what they are doing. Irregardless of the fact
that they only want to hear what makes them feel good, even if it is not
the truth.
Merlin keeps posting about his dead battery in the hopes that people
will tell him what he wants to hear, i.e. "You poor thing, don't worry
if you keep charging the battery it will magically revive." It may, but
I sure wouldn't hold my breath.
The truth is, Merlin has been flogging that battery for around two
months now and there has been no miraculous resurrection.
Parallel batteries are not a good choice.
Parallel batteries of different types, capacities and age are a dead loss.
More than two parallel strings of batteries are such a dead loss that
you can smell the rot from several hundred metres away.
Now we come to today, 12 June 2006.
It is now 4:00PM and the reg reads 12V. I'm not surprised as it has been
a fairly overcast day. Tomorrow looks to be the same forecast so tonight
I will run the battery charger generator.
5:30PM - Reg reads 12V so I start the gen set.
5:31PM - 12.5V
6:00PM - 13.4V
6:30PM - 13.5V
7:00PM - 13.6V
7:30PM - 14V
8:00PM - 14.5V
8:30PM - 15.1V
Generator out put;
30 Amps @ 16Volts
Works for me. On very rare occasions my battery set might reach 70% max
DOD. But not often. My daily DoD is around 12% (1.2kWh/day).
My system was designed for the Peak Sun Hours of the 22 June. I like to
keep my batteries charged. But, if required, my system will run with no
input at all for an honest five days of autonomy, without some mystical
reduced load.
Bitter truth or savoury lies. If you only want answers that make you
feel good - say so up front. But remember, "There is no substitute for a
properly sized and designed system. Whether you like it or not."
correctly size a system for your load, being honest about the numbers,
you end up with a system that works as planned. I seldom need to run the
battery charger.
My philosophy on battery charging.
Yes it is important that you not let them remain at a low state of
charge for long periods, on the other hand they do not need to reach
100% charge every single day either. I will run the little generator to
charge my batteries if they drop to around 12 Volts (but like the fine
print says "Conditions Apply")
1) Condition: Batteries read 12 volts (or less) at four o'clock in the
afternoon.
2) Condition: I know the sun won't be out tomorrow.
3) Condition: I need to use the computer for several hours that night.
4) Condition: There will be three hours of Red Dwarf on TV that night.
It takes at least two of these conditions to warrant the running of the
generator. And even then it comes down to gut feeling.
And when it comes to charging the batteries I am not trying to bring
them up to 100%. I am doing what I call ''Maintenance Charging'' which
is to say that I only require that they be in the top twenty per cent of
their capacity.
Yes I know it sounds like it's too easy, but the thing is that when
I started with solar power there was almost no information other than
guess work and trial and error. My life with solar power is pretty easy
these days because of what I learned from two or three disastrous years
in the beginning.
So let's say it's 4:00pm and I check the battery voltage on the reg. The
voltage reads 12V. The weather forecast is for rain for the next two
days and I have a rather lengthy paper due and expect to be on the
computer for 5 or 6 hours.
So I make a decision. I will run the battery charger. The charger is a
35Amp alternator on a petrol motor. The regulator for this rig is a
large ceramic rheostat salvaged from a very old spot welder.
The battery charger actually puts out 30 Amps and 16-17 volts at max
engine rpm. The tank holds enough fuel to run for approx. 3.5 hours when
filled to the top.
Usually around three hours of runtime will bring my batteries up to 15
volts. On some occasions I will turn the rheo down and wait for the
batteries to come back up to 15V. I may do this a couple of times, this
is of course dependent on what the voltage was at 4:00pm and what I know
about the voltage and the temp. for the last several days.
The numbers? Well, they mostly look after themselves. After nearly
twenty years of doing this sort of thing I really don't look at the
numbers any more. The reg likes to tell me that the batteries are at
100% charge. I sometimes think that it is not very honest for a little
black box.
Probably the most important thing to remember is that all the readings
are taken from a running system. As such the readings are not a true and
correct voltage reading. I do not rest the batteries, nor do I take into
account any voltage drop associated with what may be running at the time.
When the batteries read fifteen volts and I shut off the charger, I know
that if there is no load from this point on, the batteries will read
12.7 volts in the morning. What a surprise 12.7 volts is just what a
fully charged 12 volt battery should be.
Do I recommend this for everyone with a solar power system? NO!
Absolutely not.
Unless you are prepared to watch the voltage while charging you would be
best advised to use an automatic charger.
When I next run the charger I will make note of what the regulator is
telling me and relate it in this group. Don't hold your breath. I have
no control of the weather. At the moment we are in a cycle of cold
frosty mornings and cool to cold sunny days. Ideal weather for
photovoltaics.
Wayne says that I don't run my charger enough.
"Truth is the inquiring minds food, but is often bitter to the taste.
Most people prefer the savoury lie"
An example
Sunday, June 11, 2006. Voltage readings from my regulator. Overcast day
with periods of sun. Note voltage readings for 11 and 12AM as sun breaks
through.
10AM - 12.3V
11AM - 13 - 13.5V
12AM - 13.7 - 13.9V
1PM - 12.9V
2PM - 14V
3PM - 12.9V
4PM - 12.7V
This is the truth of my system. Wayne finds it bitter so he creates a
savoury lie that makes him feel good.
But as can be seen, 4:00PM and the batteries are at 12.7V. Yes, this
reading is not the true and correct voltage of the batteries. But, after
nearly twenty years of life with batteries I know that this is high
enough not to place my batteries in stress.
By far, most of the people who post here prefer the savoury lie and
there are many who are willing to support the lies because they also
want to feel good about what they are doing. Irregardless of the fact
that they only want to hear what makes them feel good, even if it is not
the truth.
Merlin keeps posting about his dead battery in the hopes that people
will tell him what he wants to hear, i.e. "You poor thing, don't worry
if you keep charging the battery it will magically revive." It may, but
I sure wouldn't hold my breath.
The truth is, Merlin has been flogging that battery for around two
months now and there has been no miraculous resurrection.
Parallel batteries are not a good choice.
Parallel batteries of different types, capacities and age are a dead loss.
More than two parallel strings of batteries are such a dead loss that
you can smell the rot from several hundred metres away.
Now we come to today, 12 June 2006.
It is now 4:00PM and the reg reads 12V. I'm not surprised as it has been
a fairly overcast day. Tomorrow looks to be the same forecast so tonight
I will run the battery charger generator.
5:30PM - Reg reads 12V so I start the gen set.
5:31PM - 12.5V
6:00PM - 13.4V
6:30PM - 13.5V
7:00PM - 13.6V
7:30PM - 14V
8:00PM - 14.5V
8:30PM - 15.1V
Generator out put;
30 Amps @ 16Volts
Works for me. On very rare occasions my battery set might reach 70% max
DOD. But not often. My daily DoD is around 12% (1.2kWh/day).
My system was designed for the Peak Sun Hours of the 22 June. I like to
keep my batteries charged. But, if required, my system will run with no
input at all for an honest five days of autonomy, without some mystical
reduced load.
Bitter truth or savoury lies. If you only want answers that make you
feel good - say so up front. But remember, "There is no substitute for a
properly sized and designed system. Whether you like it or not."