You have to sign up (free) to use it, and sometimes the response is more complicated than the question, but the guys on this site can answer just
about anything solar.Paulina - 11-2-2007 at 09:14 PM
Soulpatch,
All for free? Did you write a thank you note?
Lucky guy.
P<*)))><BajaWarrior - 11-2-2007 at 09:43 PM
What would be their use?
You don't want to mix the 6v. with the 12v.
As far as the 29/31's, they would all be equal as the weakest battery linked in series together.Mexray - 11-2-2007 at 09:51 PM
The GP29 and 31's are close enough in 'cell size' that you can probably hook them together in one battery bank...being that they are 3 years old helps
to reinforce that thought!
The 6D's you refer to have a much larger 'cell size' and would not perform very well if hooked with the others into one big battery
bank....discharging and charging would be uneven, probably resulting in the smaller cell sized batteries being charged before the 6D's, causing the
charging system to shut down and resulting in the 6D's never getting fully charged.
You might make the 6D's into a second battery bank, and then switch between the two during use, charging, etc.
I guess 'Size' does matter....Paulina - 11-2-2007 at 11:05 PM
"Talk about high end camping..."
How long of an extension cord are we going to need?
Ja ja ja
Don't worry, we won't be leaving it plugged in while we're away and I won't be stealing your beer. Just cooling my own.
P<*)))><DENNIS - 11-2-2007 at 11:10 PM
Yeah, but, it's ONLY 118 cans.Paulina - 11-2-2007 at 11:19 PM
That's why I won't be stealing any of his, duh!
That is unless you come down.
P<*)))><Bob and Susan - 11-3-2007 at 06:42 AM
speaking of "size"....
a bigger battery with 225ah life
would be much better than a smaller battery with 225ah
there is more space inside between the plates and
MORE "juice" inside to do the "magic"
just another interesting fact...
What do you mean by "bigger"?
Dave - 11-3-2007 at 08:06 AM
Quote:
Originally posted by Bob and Susan
speaking of "size"....
a bigger battery with 225ah life
would be much better than a smaller battery with 225ah
Larger footprint? More cells? Heavier?
Weight is he determining factor. Quality battery-1lb=1.2AhRoberto - 11-3-2007 at 08:18 AM
Soulpatch, I would say the critical factor is "age" of the batteries. One of the "rules" of battery banks is that you buy all the batteries at the
same time, and replace them together. That's because the older batteries affect the newer ones in terms of discharge rate, etc.
Of course, I doubt that there are that many battery purists in Baja, plus how heavily are you going to use these puppies?
The fact that they have slightly different ratings is less important. In short, my opinion is go for it.aha baja - 11-3-2007 at 09:42 AM
Another factor for battery life is to "cycle" the power in and out of the batteries. Insalling a low amp 12 vdc "dusk to dawn" in parallel on the
output demand side of your battery bank will actually extend the life. By how much is up depends on conditions such as tempuature,humidity, current in
to the array. I have 4, T-103 lead/acid 6vdc batteries in a serial-parallel configurationthat I've had for only 3 years and they are t-ts up. I have
issues with electolite levels due to extreme temperature conditions and not able to top off on a regular basis. I will be replacing them with 4-12vdc
deep cycle gel cell type (Optima)They will give 2x or more storage capacity. More $ but should last 10yr or more.Bob and Susan - 11-3-2007 at 10:36 AM
if you overcharge gel batteries you'll have a problem
that's why we didn't go with them
i REALLY like the no acid idea though
dave
my batteries are 225ah and weigh 275lbs
that's 1.22 per amp
just like you said4baja - 11-5-2007 at 07:21 PM
frank dont use optima batteries. use 6 volt acid if you can they will last way longer as long as you refill them on a regular basis. see you down
there soon. call me this week if you can .aha baja - 11-5-2007 at 09:34 PM
YEA, WHATEVERaha baja - 11-5-2007 at 09:36 PM
L.A.wiltonh - 11-5-2007 at 10:55 PM
I have 3 batteries of different types that I charge off one solar panel bank. My idea was to charge one battery until it was full and then have a
charge controller move it over to the second bank and so one.
I looked around for a commercial one and could not find any that met my needs.
This was about 2 years ago. The common term that describes these controllers is "dump mode controller". What this means is the solar panel charges
one battery or battery bank until it is full and then it dumps the power into something else. That can be another battery or often people dump into a
12V element on a water heater.
My solution was to design and build my own. The concepts are simple but it took me some testing before I got it working correctly. You might check
and see if there are more commercial options available today.
In my case, the inverter is connected to one battery and I run DC loads off the second battery. The third one is a spare which is in battery box so
it can be moved around. We used to jump start vehicles that have battery problems or run an inverter at a remote location.
Watching the controller, I notice that with my normal usage, the controller switches around noon to the second battery. That ones gets less usage
while camping so about 1pm or 2pm it will have switched over to the third battery.
Once that one is full the controller shuts off.
WiltonBob and Susan - 11-6-2007 at 06:41 AM
i've heard about controlers "dumping" the extra energy but how does it do that?
i figure some electrical "thingy" inside
and...
how did you get the controler to switch back and forth automaticly from battery to battery??
or from bank to bank????
[Edited on 11-6-2007 by Bob and Susan]wiltonh - 11-6-2007 at 08:44 AM
The way my controller works, is it monitors the voltage on the first battery. Once that reaches full charge (You choose the voltage by a zener diode)
it closes a relay which connects the solar panels to the second battery. The same process is done until all the other batteries are full. Each one
has a different zener diode so they can have different full charge voltages.
Once the last battery is full, the controller closes the final relay and could then dump the power into a water heater or any other load that you
choose.
In my case, I wait for the solar panels to go dark and then switch back to the first battery. If you were using a heavy load during the day then this
model might not work well. In my case I put a push button switch on the controller which sets the controller back to the first battery. If I need
to draw a lot of power from the first battery during the day, I push the switch just after I start drawing the power. This sets the solar panel to
charge the battery that is being used for the heavy load.
Wiltonwiltonh - 11-6-2007 at 01:18 PM
Probably the easiest way to help you out is to post a link to the electrical drawing. This may be a second new language for you but it might be worth
learning. Before I do that you need to understand a few more things. I add a colored LED and a resistor to each relay so that I know which battery
is charging. In my case this almost doubles the part count for the controller.
The real active components are as follows:
1. One blocking diode that is large enough to handle your full panel current.
2. One 12 VDC relay for each battery you wish to charge.
3. A small diode to put in reverse across its coil to keep the back emf from blowing things up.
4. One zener diode. I am using 6.2 volts because the 12 volt relays I am using click in at 8.2 volts. (calculations shown on the web page)
5. Another blocking diode for each battery.
I like to use Schottky diodes because you loose less voltage across them for the blocking diodes.
This drawing was done before I added the push button switch that takes you back to the first battery. I added that in the coil circuit of the first
relay so that when you push it the relay opens back up.
I did not show the water heater connection on this drawing but it would connect to the hot contact of the third relay when that battery was at full
charge.
.