12VDC Deep Cycle Charging with DC powered system question

[shape sweeney]

I hope some folks in this group have the expertise to help me on this
question.

I am an RV'er that likes to dry camp, and I carry (4) 115AH 12VDC
batteries. I am an artist and I use some power, OK?

Up until now, I have always charged my batteries with an AC 2/12/24 Amp
digital smart charger hooked up to my generator. My generator supplies
(2) AC 120V outlets with an average 10-13 Amps each. I have found this
setup to be pathetic in terms of performance, and am looking to set up a
more effecient system.

I will be adding solar panels soon also. But my main question is this:

Technically, all generators make DC power. They have an inverter built
in to convert to AC, since most everything uses AC. Then, my
smart-charger converts back to DC to charge the batteries. Isn't this
inefficient? Wouldn't I be better off with a DC powered smart-charger
that I could hook directly to my generators alternator, or to my 130A
truck alternator? But I need something smart, because I don't want to
ruin my batteries by overcharging.

Would the Solar charge controllers work for my application? I know that
are some DC smart chargers available for sailboats. Is that what I
should be looking for?

Thank you.
Shape Sweeney
http://www.shapesweeney.com

 

[developer]

I hope some folks in this group have the expertise to help me on this
question.

I am an RV'er that likes to dry camp, and I carry (4) 115AH 12VDC
batteries. I am an artist and I use some power, OK?

Up until now, I have always charged my batteries with an AC 2/12/24 Amp
digital smart charger hooked up to my generator. My generator supplies
(2) AC 120V outlets with an average 10-13 Amps each. I have found this
setup to be pathetic in terms of performance, and am looking to set up a
more effecient system.

I will be adding solar panels soon also. But my main question is this:

Technically, all generators make DC power. They have an inverter built
in to convert to AC, since most everything uses AC. Then, my
smart-charger converts back to DC to charge the batteries. Isn't this
inefficient? Wouldn't I be better off with a DC powered smart-charger
that I could hook directly to my generators alternator, or to my 130A
truck alternator? But I need something smart, because I don't want to
ruin my batteries by overcharging.

Would the Solar charge controllers work for my application? I know that
are some DC smart chargers available for sailboats. Is that what I
should be looking for?

Thank you.
Shape Sweeney
http://www.shapesweeney.com

take a look at http://www.web7days.com/led/

 

[Robert Morein]

I hope some folks in this group have the expertise to help me on this
question.

I am an RV'er that likes to dry camp, and I carry (4) 115AH 12VDC
batteries. I am an artist and I use some power, OK?

Up until now, I have always charged my batteries with an AC 2/12/24 Amp
digital smart charger hooked up to my generator. My generator supplies
(2) AC 120V outlets with an average 10-13 Amps each. I have found this
setup to be pathetic in terms of performance, and am looking to set up a
more effecient system.

I will be adding solar panels soon also. But my main question is this:

Technically, all generators make DC power. They have an inverter built
in to convert to AC, since most everything uses AC. Then, my
smart-charger converts back to DC to charge the batteries. Isn't this
inefficient? Wouldn't I be better off with a DC powered smart-charger
that I could hook directly to my generators alternator, or to my 130A
truck alternator? But I need something smart, because I don't want to
ruin my batteries by overcharging.

Would the Solar charge controllers work for my application? I know that
are some DC smart chargers available for sailboats. Is that what I
should be looking for?

Many of the solar chargers cut off charge by shunting the panel input, ie.,
putting a short circuit across them.
This would be a disaster for a generator.
Some do not.
The Outback MX-60 is a candidate for this, but the Outback people have
informed me that spikes, such as those generated by alternator brushes,
could throw the tracking algorithm off. On the other hand, if your generator
has a starter battery across it at all times, the capacity of the battery
would filter some of the noise.

These are just thoughts. I don't have a positive answer to your question.

 

[Jack Daynes]

I hope some folks in this group have the expertise to help me on this
question.

I am an RV'er that likes to dry camp, and I carry (4) 115AH 12VDC
batteries. I am an artist and I use some power, OK?

Up until now, I have always charged my batteries with an AC 2/12/24 Amp
digital smart charger hooked up to my generator. My generator supplies
(2) AC 120V outlets with an average 10-13 Amps each. I have found this
setup to be pathetic in terms of performance, and am looking to set up a
more effecient system.

I will be adding solar panels soon also. But my main question is this:

Technically, all generators make DC power. They have an inverter built
in to convert to AC, since most everything uses AC.

=================================
Not usually true. Though we like to call them
'generators', they are usually 'alternators' and
manufacture AC directly.
=================================

Then, my
smart-charger converts back to DC to charge the batteries. Isn't this
inefficient? Wouldn't I be better off with a DC powered smart-charger
that I could hook directly to my generators alternator, or to my 130A
truck alternator? But I need something smart, because I don't want to
ruin my batteries by overcharging.

Would the Solar charge controllers work for my application? I know that
are some DC smart chargers available for sailboats. Is that what I
should be looking for?

=================================
I can see no reason that Solar panels won't charge
your batteries. As long as it has a 'regulator' to
control the charging parameters that your battery
requires.
=================================

Thank you.
Shape Sweeney
http://www.shapesweeney.com

=================================
Be sure to check the charging parameters required
for the batteries they are using. Lead-Antimony
and Lead-Calcium chemistries each have
dramatically different requirements. THe SPGR will
have some influence as well.

Good Luck,
--
-- Jack --
=================================
Everything you see is temporary.
=================================
Clean Up Return Address To Reply
=================================
Poway, California (San Diego Co.)
N 32° 57' W 117° 04'
At 508' Elevation
=================================

 

[wmbjk]

I hope some folks in this group have the expertise to help me on this
question.

I am an RV'er that likes to dry camp, and I carry (4) 115AH 12VDC
batteries. I am an artist and I use some power, OK?

Up until now, I have always charged my batteries with an AC 2/12/24 Amp
digital smart charger hooked up to my generator. My generator supplies
(2) AC 120V outlets with an average 10-13 Amps each. I have found this
setup to be pathetic in terms of performance, and am looking to set up a
more effecient system.

I will be adding solar panels soon also. But my main question is this:

Technically, all generators make DC power. They have an inverter built
in to convert to AC, since most everything uses AC. Then, my
smart-charger converts back to DC to charge the batteries. Isn't this
inefficient? Wouldn't I be better off with a DC powered smart-charger
that I could hook directly to my generators alternator, or to my 130A
truck alternator? But I need something smart, because I don't want to
ruin my batteries by overcharging.

Would the Solar charge controllers work for my application? I know that
are some DC smart chargers available for sailboats. Is that what I
should be looking for?

Thank you.
Shape Sweeney
http://www.shapesweeney.com

Nice work on the carvings.

Your present setup isn't so bad. Check the fuel consumption numbers
here to compare http://www.frenergy.net/gdc/ a purpose-built machine.
Click on the 100-12 model, and ignore the "efficiency" fluff. If you
like the basic concept, but don't like the price, then this might
interest you http://theepicenter.com/tow02077.html

Using your truck's alternator isn't going to be a more efficient
alternative if you have to run the vehicle engine in place for
charging. But if there's enough driving time to do the charging, then
maybe.... you need some consumption and driving time numbers etc. to
even consider the idea. Don't forget that the truck's alternator
actually makes AC, and a rectifier changes that to DC for charging.
http://members.1stconnect.com/anozira/SiteTops/energy/Alternator/alternator.htm

If there might be a new generator in your future, then you could
consider something like this
http://www.smallenginewarehouse.com/product.asp?PN=HHG-EU2000 Nice AC
features like low engine RPM when your AC loads are low, and a small
12V output as well. Somebody will know whether you'd need an external
charge controller to go with it. You'd want to evaluate whether your
normal generator run time (for AC loads) would be sufficient for
simultaneous DC charging, or whether you might still use the external
charger. For help with that, you might describe your loads and habits.

If you were starting from scratch, my preference would be the Honda
EU, and a combination inverter/charger, like this
http://store.solar-electric.com/dr1512.html Add solar panels as budget
allows to reduce or eliminate generator run time.

Wayne

 

[JM]

quoting:

I hope some folks in this group have the expertise to help me on this
question.

I am an RV'er that likes to dry camp, and I carry (4) 115AH 12VDC
batteries. I am an artist and I use some power, OK?

Up until now, I have always charged my batteries with an AC 2/12/24 Amp
digital smart charger hooked up to my generator. My generator supplies
(2) AC 120V outlets with an average 10-13 Amps each. I have found this
setup to be pathetic in terms of performance, and am looking to set up a
more effecient system.

I will be adding solar panels soon also. But my main question is this:

Technically, all generators make DC power. They have an inverter built
in to convert to AC, since most everything uses AC. Then, my
smart-charger converts back to DC to charge the batteries. Isn't this
inefficient? Wouldn't I be better off with a DC powered smart-charger
that I could hook directly to my generators alternator, or to my 130A
truck alternator? But I need something smart, because I don't want to
ruin my batteries by overcharging.

Actually, it's the other way around. Generators produce AC, althouth usually
considered "dirty power", but it's AC. Vehicle alternators initally produce
AC, but have a set of diodes that recify the AC into DC.

Would the Solar charge controllers work for my application? I know that
are some DC smart chargers available for sailboats. Is that what I
should be looking for?

Good move on the solar. How big are your panels going to be and how much do
you use out of your batteries before you recharge? Generally, you want
enough power to top off your batteries before daylight runs out.

 

[shape sweeney]

Nice work on the carvings.

Your present setup isn't so bad. Check the fuel consumption numbers
here to compare http://www.frenergy.net/gdc/ a purpose-built machine.
Click on the 100-12 model, and ignore the "efficiency" fluff. If you
like the basic concept, but don't like the price, then this might
interest you http://theepicenter.com/tow02077.html

Using your truck's alternator isn't going to be a more efficient
alternative if you have to run the vehicle engine in place for
charging. But if there's enough driving time to do the charging, then
maybe.... you need some consumption and driving time numbers etc. to
even consider the idea. Don't forget that the truck's alternator
actually makes AC, and a rectifier changes that to DC for charging.
http://members.1stconnect.com/anozira/SiteTops/energy/Alternator/alternator.htm

If there might be a new generator in your future, then you could
consider something like this
http://www.smallenginewarehouse.com/product.asp?PN=HHG-EU2000 Nice AC
features like low engine RPM when your AC loads are low, and a small
12V output as well. Somebody will know whether you'd need an external
charge controller to go with it. You'd want to evaluate whether your
normal generator run time (for AC loads) would be sufficient for
simultaneous DC charging, or whether you might still use the external
charger. For help with that, you might describe your loads and habits.

If you were starting from scratch, my preference would be the Honda
EU, and a combination inverter/charger, like this
http://store.solar-electric.com/dr1512.html Add solar panels as budget
allows to reduce or eliminate generator run time.

Wayne

Thank you all for this great information. And thanks for the compliment!

I didn't go into any detail about my power requirements, but this is why
I an not your normal RV'er that is dry camping. I like to go to remote
areas with my wife and dogs to do my art work. The solitude and
inspiration are helpful.

To produce my art work, I use a multitude of power tools, including a
6HP compressor (I'm looking for a smaller one, this one won't even run
on my 3500w genny), an electric angle grinder, 1/8hp flex shaft carving
machine, drills, etc.

The flex-shaft I can run off my batteries for several hours. Most of
the other power tools must be used with the genny. I have been trying
to get sufficient battery power to run the other tools also, along with
the requirements of the trailer (tv, microwave, etc.), but I think I am
figuring out that is not going to work. My genny is just to loud.

So, I think that if I get one of those Honda EU2000's and a couple of
solar panels, I can probably get by with running the genny about 4 hours
daily and keep my battery banks charged simultaneously. Regardless of
how much juice you are making, it takes a long time to properly charge
deep cycle batteries if they are deeply discharged. I think the solar
panels will really help.

What do you guys think of my plan then?

 

[wmbjk]

So, I think that if I get one of those Honda EU2000's and a couple of
solar panels, I can probably get by with running the genny about 4 hours
daily and keep my battery banks charged simultaneously. Regardless of
how much juice you are making, it takes a long time to properly charge
deep cycle batteries if they are deeply discharged. I think the solar
panels will really help.

What do you guys think of my plan then?

Sounds good. I think the EU will make your off-grid time a lot more
pleasant. Whatever changes you make, please post your comments about
how they worked out.

Here's a cheap and accurate tool to help with your planning. Might
even be useful when shopping for a compressor.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=3240&item=5964010411&rd=1

Speaking of compressors,
http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=38898
It's a crummy model, but I've seen them last for years of occasional
use. Startup draw is going to be the limiting factor, so ideally you'd
want to try before buying. BTW, ignore those HP stickers on
compressors. If it plugs into a standard household receptacle, then
it's no more than 2HP. Go by the motor data plate numbers, or better
yet your own measurements if possible.

A system monitoring device might be overkill for your setup, but
having one would be nice. Here's an example
http://www.affordable-solar.com/471.html

Wayne

 

[Laurie]

"developer" [email protected] wrote in message

take a look at http://www.web7days.com/led/

Let's see: "Solar Panel size 210 X 210 cm", "10.00 Volts at > 1000 ma"
Thus, size = ~ 83 inches x 83 inches; output = 10 Watts.
Seems a bit impractical for backpacking, or anything else.
Nice way to get a plug in, tho'<G.

Laurie

 

[Bill Kaszeta / Photovoltaic Resources]

"developer" [email protected] wrote in message

Let's see: "Solar Panel size 210 X 210 cm", "10.00 Volts at > 1000 ma"
Thus, size = ~ 83 inches x 83 inches; output = 10 Watts.
Seems a bit impractical for backpacking, or anything else.
Nice way to get a plug in, tho'<G.

Laurie

And every thing else is giant size!

More likely 210 mm.


Bill Kaszeta
Photovoltaic Resources Int'l
Tempe Arizona USA
[email protected]