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Connecting batteries in parallel - some questions:

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Jim

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Dec 27, 2009, 3:10:29 PM12/27/09
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I have just begun experimenting with a Kyocera 50 watt and have a 65
watt panel ordered, using the smaller panels mainly because they
can be easily handled, and I can buy one when I get some
extra cash. Each panel has a Morningstar SunGuard
controller, good for 4.5 amps or up to an 80 watt panel.

According to the Morningstar website, as money becomes
available, I can just keep adding the panels and controllers
to the same battery bank with no interaction, and the
controllers will act in unison to charge the batteries as
if it was one larger controller. Is this the case or is it
just advertising baloney? I'd like to find out for sure
before buying a 3rd panel and controller.

About the battery "bank". Are there any rules about adding
additional batteries in parallel? It seems to me that if
you keep adding them in parallel, they should be somewhat
matched, that is, same brand and model, keeping capacities
of each unit about the same. Is this correct, or can you do
like they did in that TV show "The Colony" where they got
all kinds of odd size/condition batteries and wired them in parallel
for their "bank"?

I now have a new "Energizer 27DC" deep cycle, and an
older "Energizer 73DT" available to play with, and they
are physically different sized and probably electrically
different. The Energizer 27 DC is available at the local
Sam's club and is the largest one they carried that I could
lift without too much problem, and is supposedly for "Deep
Cycle" use.

Anyway, should I just keep buying the "Energizer 27DC"
when funds become available and adding them in parallel, or
can you just add any size 12v battery as long as it's new and
in good shape? I want to keep things to manageable weights
and sizes so I can eventually move everything to another
location when things get nasty....

I guess what I'm lookig for is a good tutorial on how to
build up a battery "bank" using the smaller batteries.
Sam's Club also carries some larger 6V batteries probably for
golf carts, but they are pretty heavy for one person to
be throwing around. Should I go with them in series-parallel
or can I stick with the Energizer 27DC to build up a bank?
Trojans are not available locally without paying big shipping costs.

I'll be using the bank only during emergencies for powering ham radio
equipment,
12v Solsum lamps and some other 12V linear flourescents,
some computer equipment and perhaps some small kitchen appliances
running off an inverter. Also a 12V fan or two, (as what I went
through after Katrina I never want to go through again).
We also have a Honda (converted to NG) generator thanks to FEMA
for backup as long as the natural gas/gasoline/propane lasts, but
if we have to leave for parts unknown we can't count on fuel
availability for the Honda.

(FYI: I have found that not all inverters are equal if you are
running radio equipment. The el-cheapo inverters you buy in auto
parts stores put out huge amounts of hash all over the radio
spectrum, making sensitive reception impossible. I found this out
when attempting to use a 500 watt inverter while operating my
mobile HF station, it destroyed reception. When I buy another
inverter i will bring a portable shortwave receiver and give
it the reception test). Anyone know a good clean inverter?

ghio

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Dec 27, 2009, 7:55:38 PM12/27/09
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Regulators - Buy one (1) that will handle all the panels that you
intend to purchase.

Batteries - Should all be of the same capacity and age. Buy a set that
will meet your needs for the system you intend to build.

Inverters - Buy one (1) true sine wave inverter that is of a size that
will meet the total load expected from your system.

Lights - Consider LED lighting. There are some very good products
available on the market.

El-cheapo - For an emergency power back up, ROTFLMAO.

cl...@snyder.on.ca

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Dec 27, 2009, 11:46:30 PM12/27/09
to

The general rule is only parallel connect cells of the same size,make,
and age. Sometimes you can get away with mixing brands or capacities
or ages - other times it "bites you".
Most definitely you have the best chance of getting maximum life and
performance out of a matched set - but even better is to buy big
enough and series connect - ie - buy big 6 volts and use 2 in series
rather than small 12 volts (physically the same size) in parallel.

z

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Dec 28, 2009, 2:08:35 PM12/28/09
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Jim <nos...@nospam.com> wrote in news:73cfj5d214e976uqjbfjcm4b5srh9mfh55@
4ax.com:

> I have just begun experimenting with a Kyocera 50 watt and have a 65
> watt panel ordered, using the smaller panels mainly because they
> can be easily handled, and I can buy one when I get some
> extra cash. Each panel has a Morningstar SunGuard
> controller, good for 4.5 amps or up to an 80 watt panel.
>
> According to the Morningstar website, as money becomes
> available, I can just keep adding the panels and controllers
> to the same battery bank with no interaction, and the
> controllers will act in unison to charge the batteries as
> if it was one larger controller. Is this the case or is it
> just advertising baloney? I'd like to find out for sure
> before buying a 3rd panel and controller.

I don't know about the morninstar ones. I don't think they'd lie to you
about that, though. Morningstar is pretty respected company I think.

You can run more than one controler -- like I have one 10 amp controller
for some of my solar panels, and another 35 amp that takes my hydro + 2
other large panels. So if you split your panels each into a different
controller that can take the amps then you'd be OK.

>
> About the battery "bank". Are there any rules about adding
> additional batteries in parallel? It seems to me that if
> you keep adding them in parallel, they should be somewhat
> matched, that is, same brand and model, keeping capacities
> of each unit about the same. Is this correct, or can you do
> like they did in that TV show "The Colony" where they got
> all kinds of odd size/condition batteries and wired them in parallel
> for their "bank"?
>
> I now have a new "Energizer 27DC" deep cycle, and an
> older "Energizer 73DT" available to play with, and they
> are physically different sized and probably electrically
> different. The Energizer 27 DC is available at the local
> Sam's club and is the largest one they carried that I could
> lift without too much problem, and is supposedly for "Deep
> Cycle" use.
>
> Anyway, should I just keep buying the "Energizer 27DC"
> when funds become available and adding them in parallel, or
> can you just add any size 12v battery as long as it's new and
> in good shape? I want to keep things to manageable weights
> and sizes so I can eventually move everything to another
> location when things get nasty....
>

As I understand it, the weakest, oldest battery in the bank will
determine the efficiency of all the other batteries. That's why everyone
says 'buy the same kind, same age all at once'. Like clare & ghio said.
So when you add another battery you can add some capacity but the rest of
the bank will only charge to the capacity of the worst battery in the
bank.


>
> (FYI: I have found that not all inverters are equal if you are
> running radio equipment. The el-cheapo inverters you buy in auto
> parts stores put out huge amounts of hash all over the radio
> spectrum, making sensitive reception impossible. I found this out
> when attempting to use a 500 watt inverter while operating my
> mobile HF station, it destroyed reception. When I buy another
> inverter i will bring a portable shortwave receiver and give
> it the reception test). Anyone know a good clean inverter?

I had the same problem with the cheap inverters that can be reduced by
getting an RF filter, but once I had the $$ I got a xantrex 1000 watt
true sine and haven't been disapointed. It's got a remote panel so you
can see what your loads are and it goes into sleep mode etc when you are
not using it. No RF interference and nice clean power. Found one on
fleabay for 200 bucks .. most of the time they are a lot more though.

Best of luck

-zachary

>
>
>

Jim

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Dec 28, 2009, 10:32:34 PM12/28/09
to
I found this site that recommends NOT to use parallel batteries:

http://www.rpc.com.au/products/batteries/deepcycle_faq.html


I am thinking I'll get the same Energizer deep cycle and place
them in parallel, as they will all be same and new, and I can
just lift them without too much trouble. The 6V batteries were
too heavy for this old geezer and had no handles on them. Am
awaiting the second panel.

Thanks for all the suggestions.

Jim

Josepi

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Dec 28, 2009, 10:39:55 PM12/28/09
to
Some tricks are to keep the lead lengths the same to a common star point,
same size conductors, and generally make the charging/discahrging currents
split equally.


"Jim" <nos...@nospam.com> wrote in message
news:nmtij5tbd654sn78c...@4ax.com...

Daniel who wants to know

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Jan 1, 2010, 5:37:27 PM1/1/10
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"Josepi" <J...@invaliid.con> wrote in message
news:aSe_m.96063$Zu5....@newsfe24.iad...

> Some tricks are to keep the lead lengths the same to a common star point,
> same size conductors, and generally make the charging/discahrging currents
> split equally.
>
>


Correct. Always use a star point connection or a "cross connection" (not
sure of the proper terms). Never a straight connection.

See:
Cross:
http://www.class-c-motorhome-info-made-simple.com/images/Batteries_In_Parallel.jpg
Straight:
http://i.ehow.com/images/GlobalPhoto/Articles/4448303/parallel-battery2_Full.jpg


ghio

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Jan 1, 2010, 7:00:29 PM1/1/10
to
On Jan 2, 9:37 am, "Daniel who wants to know" <m...@here.edu> wrote:
> "Josepi" <J...@invaliid.con> wrote in message
>
> news:aSe_m.96063$Zu5....@newsfe24.iad...
>
> > Some tricks are to keep the lead lengths the same to a common star point,
> > same size conductors, and generally make the charging/discahrging currents
> > split equally.
>
> Correct. Always use a star point connection or a "cross connection" (not
> sure of the proper terms).  Never a straight connection.
>
> See:
> Cross:http://www.class-c-motorhome-info-made-simple.com/images/Batteries_In...
> Straight:http://i.ehow.com/images/GlobalPhoto/Articles/4448303/parallel-batter...

Both links show the second best option, parallel batteries should be
avoided where ever possible. Use batteries of the correct Ah rating
rather than parallel batteries. Six- 2volt, 600Ah batteries in series
is preferred over six 12volt, 100Ah batteries in parallel.

Josepi

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Jan 1, 2010, 8:00:21 PM1/1/10
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Most would call that a "daisy chain" connection. Straight is not
descriptive.


"Daniel who wants to know" <m...@here.edu> wrote in message
news:hhltf8$80g$1...@news.eternal-september.org...

sno

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Jan 1, 2010, 11:16:21 PM1/1/10
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I have often wondered when connecting batteries in parallel, if sharing
of the electrolyte between batteries (a tube between batteries...??)
would solve the unequal voltage problem.

Any thoughts on this would be appreciated...

thank you for listening to my thoughts.....sno

Daniel who wants to know

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Jan 2, 2010, 12:02:00 AM1/2/10
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"Josepi" <J...@invaliid.con> wrote in message
news:jUw%m.539$rH7...@newsfe19.iad...

> Most would call that a "daisy chain" connection. Straight is not
> descriptive.
>
>
Thank you for the help with the terminology I will make a note of it.


Josepi

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Jan 2, 2010, 11:39:12 AM1/2/10
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There are the plate chemistries to consider. I doubt this would equalize
thing. Probably make the unequal chemistries worse. Plates would get more
saturated and liquids would get weaker or vice versa.

"sno" <s...@opelc.com> wrote in message
news:4b3ec883$0$65833$892e...@auth.newsreader.octanews.com...

sno

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Jan 2, 2010, 12:02:04 PM1/2/10
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I was thinking using the same manufacturer/same type battery, sharing
the electrolyte would keep the specific gravity of both batteries the
same. The plate chemistry would be the same and the electrolyte.

Isn't the specific gravity directly related to charge...?? As long as
the specific gravity is the same, the charges would be the same.

--
Correct Scientific Terminology:
Hypothesis - a guess as to why or how something occurs
Theory - a hypothesis that has been checked by enough experiments
to be generally assumed to be true.
Law - a hypothesis that has been checked by enough experiments
in enough different ways that it is assumed to be truer then a theory.
Note: nothing is proven in science, things are assumed to be true.

Josepi

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Jan 2, 2010, 12:55:33 PM1/2/10
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Think about the chemistry that happens when it accepts a charge. The plates
have to have something done to them as well as the electrolytes.

I think swapping electrolytes would leave the plates "yearning" fo whatever
chemistry is owing when they recharge.

Sulphated plates can be rejuvenated quick successfully according to Ghio,
here. I have no experience with this process but I should find out soon. I
have a relatively new bank that is in bad shape from depending on the charge
with PV solely and deep discharging too often.


"sno" <s...@opelc.com> wrote in message

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ghio

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Jan 3, 2010, 3:22:56 PM1/3/10
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If sharing electrolyte you would have a single cell not a battery.

Jim

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Jan 9, 2010, 6:22:47 AM1/9/10
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It seems to me that electrically they are identical. Am I wrong here?

vaughn

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Jan 9, 2010, 9:49:01 AM1/9/10
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"Jim" <nos...@nospam.com> wrote in message
news:ulpgk5hsbr7scaqbq...@4ax.com...

> It seems to me that electrically they are identical. Am I wrong here?
>
Post top or bottom as you wish. But since we can't read your mind, at least
give us a bit of context so we know what "they" you are thinking about. Then
perhaps we can give you a meaningful answer.

Vaughn


Daniel who wants to know

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Jan 10, 2010, 9:40:30 PM1/10/10
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"Jim" <nos...@nospam.com> wrote in message
news:ulpgk5hsbr7scaqbq...@4ax.com...

> It seems to me that electrically they are identical. Am I wrong here?
>
>
>
Yes and no, all 3 schemes are electrically identical in that the batteries
are in parallel but only star or "cross" as I call it allows for an equal
length and thus resistance path through the cabling to each battery. When
connected as a string the battery closest to the source or load will hog
almost all of the current due to the resistance of the cabling between each
battery. When star connected with equal lengths (and gauges) of cable the
current will be shared equally, similarly with "cross" if you draw a line
from the main positive to the main negative through each battery 1 at a time
you will see that the cabling length is equal no matter which you go
through.


Jim

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Jan 11, 2010, 8:48:45 PM1/11/10
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Thanks Daniel, that's the way I will wire it, Cross.
I plan to pick up another identical deep cycle in the
next few days, install the seconc panel now sitting in the garage
awaiting warmer weather, and add on panels/batteries as the finances
permit. It would probably pay to have extra jumpers made
up at this time, all identical for future use. Thanks
again for the information.

Jim

Josepi

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Jan 13, 2010, 12:16:06 PM1/13/10
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Not when you consider micro-ohmic values for large currents.

Ignore the trolling responses that are off-topic. It runs amuck here...LOL


"Jim" <nos...@nospam.com> wrote in message

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Josepi

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Jan 13, 2010, 12:17:00 PM1/13/10
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Think of every connection as a small resistor and every inch of wire as a
resistor and then do the math.


"Jim" <nos...@nospam.com> wrote in message

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