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24 volts DC 40 amp voltage stabilizer

  • Thread starter RamRod Sword of Baal
  • Start date
R

RamRod Sword of Baal

Jan 1, 1970
0
I have a particular set up for powering my computers. We are on mains power
(Australia 240 volts 50 cycles) but I have a system for running the
computers, it has 4 x 6 volt T105 batteries (24 volt ) and a 2500 watt
inverter.

There are as many as 9 computers can be put on line, but in actual fact
normally it would only be 2 or possibly 3, depending what is happening in
the house. I cannot see where we would ever have as many as 5 running at one
time.

The system allows for running a TV and fridge in case of a power failure.

The power for the batteries comes from a simple 40 amp 24 volt charger, it
is a transformer and rectifier. It is a solidly built unit that I had made
for the job.

I also had a 25 amp electronic charger but it has failed and needs repair or
replacement.

These large chargers are quite expensive here in Australia, for instance a
24 volt 25 amp charger can run up above $1000.00.

The inverter is a sinewave job and cost $2500.00 so any idea of throwing
away what I have and replacing it is not on.



Now comes the problem. The battery charger being only a simple battery
charger need the battery voltage to drop quite a bit before you can get a
large current out of it. I want to maintain around 27 volts in the batteries
and have the charger put in what ever the inverter is dragging out, so if
the inverter is using say 20 amps, I need to put in 20 amps, plus a small
maintenace charge for the batteries and maintain the 27 volts in the
batteries, so I am not constantly draining and recharging the batteries thus
reducing their life.

I have seen one of these devices in the past, but unfortunately lost the
link.

It is an electronic 'box of tricks' rated around 40 amps that you can put is
a DC voltage and get out a constant dc voltage.

As I can increase the DC voltage from my current simple battery charger to
up over 40 volts if I so desire, I am looking at buying something that would
give me a constant or near constant 27 volts, and rated at 40 amps output to
maintain the batteries at full charge. Of course the 'box of tricks' needs
to modulate the current to maintain the 27 volts in the system between 0 and
40 amps

I understand it might not be able to hold it at exactly 27 volts, but it
would want it to be somewhere near that number.

At the moment I seem to be having the problem of either pulling power out of
the batteries or over charging them, depending on what setting I use on the
battery charger.

Has anyone seen such a thing (DC Voltage stabilizer), and knows where I can
get one, or has a circuit diagram for something like this?

I have not been able to find anything using Google.
 
R

RamRod Sword of Baal

Jan 1, 1970
0
RamRod Sword of Baal said:
I have a particular set up for powering my computers. We are on mains
power (Australia 240 volts 50 cycles) but I have a system for running the
computers, it has 4 x 6 volt T105 batteries (24 volt ) and a 2500 watt
inverter.

There are as many as 9 computers can be put on line, but in actual fact
normally it would only be 2 or possibly 3, depending what is happening in
the house. I cannot see where we would ever have as many as 5 running at
one time.

The system allows for running a TV and fridge in case of a power failure.

The power for the batteries comes from a simple 40 amp 24 volt charger, it
is a transformer and rectifier. It is a solidly built unit that I had made
for the job.

I also had a 25 amp electronic charger but it has failed and needs repair
or replacement.

These large chargers are quite expensive here in Australia, for instance a
24 volt 25 amp charger can run up above $1000.00.

The inverter is a sinewave job and cost $2500.00 so any idea of throwing
away what I have and replacing it is not on.



Now comes the problem. The battery charger being only a simple battery
charger need the battery voltage to drop quite a bit before you can get a
large current out of it. I want to maintain around 27 volts in the
batteries and have the charger put in what ever the inverter is dragging
out, so if the inverter is using say 20 amps, I need to put in 20 amps,
plus a small maintenace charge for the batteries and maintain the 27 volts
in the batteries, so I am not constantly draining and recharging the
batteries thus reducing their life.

I have seen one of these devices in the past, but unfortunately lost the
link.

It is an electronic 'box of tricks' rated around 40 amps that you can put
is a DC voltage and get out a constant dc voltage.

As I can increase the DC voltage from my current simple battery charger to
up over 40 volts if I so desire, I am looking at buying something that
would give me a constant or near constant 27 volts, and rated at 40 amps
output to maintain the batteries at full charge. Of course the 'box of
tricks' needs to modulate the current to maintain the 27 volts in the
system between 0 and 40 amps

I understand it might not be able to hold it at exactly 27 volts, but it
would want it to be somewhere near that number.

At the moment I seem to be having the problem of either pulling power out
of the batteries or over charging them, depending on what setting I use on
the battery charger.

Has anyone seen such a thing (DC Voltage stabilizer), and knows where I
can get one, or has a circuit diagram for something like this?

I have not been able to find anything using Google.


I should have made the point that I want to use the DC power from my current
simple battery charger to feed into a DC to DC voltage stabilizer.
 
V

Vaughn Simon

Jan 1, 1970
0
RamRod Sword of Baal said:
Has anyone seen such a thing (DC Voltage stabilizer), and knows where I can
get one, or has a circuit diagram for something like this?

I have not been able to find anything using Google.

Perhaps you don't need a stabilizer at all. The problem is that you are
trying to use that "dumb" power supply to do two jobs at once. Perhaps you need
to use that "dumb" power supply for the heavy work while you use a much smaller
"smart" charger to keep your batteries topped off.

First of all, let me ask you this: If you didn't have the batteries at all,
would you still trust that power supply enough to run your computers directly
from it? If no, then stop reading

If yes, then you can get along fine with a diode isolator (battery backup
module) which will allow your power supply to normally power your computers, and
will resort to the batteries only when the power supply dips below the battery
voltage. (This model won't work for you, but here is a manual for one.
http://tinyurl.com/69z2mn
All you really need is two diodes, build it yourself.) You could maintain the
charge of the battery with a small, but high quality 24-volt battery charger
like this: http://batterytender.com/product_info.php?products_id=9
 
B

Bruce in alaska

Jan 1, 1970
0
RamRod Sword of Baal said:
Has anyone seen such a thing (DC Voltage stabilizer), and knows where I can
get one, or has a circuit diagram for something like this?

I have not been able to find anything using Google.

What I use is a Regulated DC Power Supply, as a Battery Charger.
I set the Output Voltage of the Regulator, to what I figure should
be Float Voltage, for the battery type, Minus .3 Vdc. I have a
pair of L16HD's, in series, that supply the 12 Vdc Buss that runs my
Radioroom/Office. Using a Regulated Dc Power Supply with the Output
Voltage set at 13.3 Vdc, and capable of supplying 40 amps. My Base
Load is usually in the neighborhood of 7 Amps, and jumps to Max of
50 amps, when one of the Transmitters is operating. The Battery
Bank will support the load thru ANY Communication Session, and will then
be recharged back to float, within a few hours after heavy use, all
while maintaining a Buss Voltage, above 12.3 Vdc. Since I generate
ALL my own power, and the genset only runs 10 hours a day, and the
Regulated Power Supply, is not powered unless the Genset is online,
this keeps my Radioroom/Office running 24/7/365, and the Battery
Bank fully charged, and back at Float Voltage, at least twice a day.

The only difference between your cheap Battery Charger, and my Regulated
DC Power Supply, is the Voltage Regulation Circuits my unit has, after
the Rectifier.
 
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