Connecting my 2 Batteries to 1 Solar Panel

[Dan G[_2_]]

I would like to connect my 2 8AH batteries to one Solar panel for charging while the glider is in its trailer. I will use a controller and I have 2 separate sockets in the glider-one per battery.

I thought to simply split the wires coming out of the controller to the two batteries/sockets but I came across this:
http://www.morningstarcorp.com/en/support/library/ALL.APP.Isolated_banks_1_controller.01.EN.pdf,

Any suggestions?
Dan G

[Eric Greenwell[_4_]]

On 12/31/2012 6:49 PM, Dan G wrote:
> I would like to connect my 2 8AH batteries to one Solar panel for
> charging while the glider is in its trailer. I will use a controller
> and I have 2 separate sockets in the glider-one per battery.
>
> I thought to simply split the wires coming out of the controller to
> the two batteries/sockets but I came across this:
> http://www.morningstarcorp.com/en/support/library/ALL.APP.Isolated_banks_1_controller.01.EN.pdf,
>
> Any suggestions?

It looks like it would work adequately for your 8 AH batteries. If not,
I suggest you use the technique they reference: two controllers, one for
each battery, but fed by a single PV panel:

http://www.morningstarcorp.com/en/support/library/ALL.APP.Isolated_Batteries.01.EN.pdf

It's the technique I use in my trailer to charge the glider battery and
auxiliary battery in the front of the trailer. Seems to work well. The
advantage is the batteries will charge more quickly, and to the proper
voltage. Even so, it might not make much difference in the amount of
charge each one gets.

Alternatively, you could get a dual output controller, one output for
each battery.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)

[Dan G[_2_]]

Eric,
What diode would you use for the 2 contollers/1 pV option you use ?
My Solar panel is rated at 20W od 1.3A max.
Dan G
On Monday, December 31, 2012 9:49:58 PM UTC-5, Dan G wrote:
> I would like to connect my 2 8AH batteries to one Solar panel for charging while the glider is in its trailer. I will use a controller and I have 2 separate sockets in the glider-one per battery.
>
>
>
> I thought to simply split the wires coming out of the controller to the two batteries/sockets but I came across this:
>
> http://www.morningstarcorp.com/en/support/library/ALL.APP.Isolated_banks_1_controller.01.EN.pdf,
>
>
>
> Any suggestions?
>
> Dan G

[Eric Greenwell[_4_]]

On 12/31/2012 7:31 PM, Dan G wrote:
> Eric,
> What diode would you use for the 2 contollers/1 pV option you use ?
> My Solar panel is rated at 20W od 1.3A max.
> Dan G

I'd just go to Radio Shack and get ones rated at 2 amps or more forward
current. They will all have enough voltage rating.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)

[Darryl Ramm]

On Monday, December 31, 2012 8:18:40 PM UTC-8, Eric Greenwell wrote:
> On 12/31/2012 7:31 PM, Dan G wrote:
>
> > Eric,
>
> > What diode would you use for the 2 contollers/1 pV option you use ?
>
> > My Solar panel is rated at 20W od 1.3A max.
>
> > Dan G
>
>
>
> I'd just go to Radio Shack and get ones rated at 2 amps or more forward
>
> current. They will all have enough voltage rating.
>
>
>
> --
>
> Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
>
> email me)

There is a slight benefit in using a Schottky diode in this application for their lower forward voltage drop. For the one controller sceanario this is more important as it affects the charge set point of the controller. But it also helps the other scenario as well. e.g. http://www.amazon.com/30pcs-1N5822-SCHOTTKY-Barrier-Rectifier/dp/B007AU0GJI. I would not go to too lower diode forward current rating due to current derating (maybe 50%?) at temperatures they might happen in a charger environment/hot trailer.

I hope there is not a too high expectation about how fast a "20W" panel will charge these two batteries. Solar insolation on a flat non-tracking panel gets pretty low.

Darryl

[RAS56]

I took the easy way out and ordered one of these:

http://www.amazon.com/gp/product/B002LC72W4/ref=oh_details_o05_s00_i00

40 bucks.

It has worked great with my 10 watt panel, is programmable and tells me the charge status of each battery.

ZAP

[Eric Greenwell[_4_]]

On 1/1/2013 6:26 PM, RAS56 wrote:
> I took the easy way out and ordered one of these:
>
> http://www.amazon.com/gp/product/B002LC72W4/ref=oh_details_o05_s00_i00
>
> 40 bucks.
>
> It has worked great with my 10 watt panel, is programmable and tells
> me the charge status of each battery.

This kind of controller would be a good choice for the OP, where both
batteries are in the glider. I used separate controllers for my
application, one in the glider for the glider battery, and the other at
the front of the trailer, where my auxiliary battery is kept. That keeps
the controllers in the temperature zone as the battery, and keeps the
wires to battery much shorter.

The auxiliary battery used with a DC/DC charger to charge the glider
battery when the glider is tied down away from the trailer.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)

[Dan G[_2_]]

Thanks for the advice.
Now-if I connect these two batteries in oarallel- do I still need the two separate systems or I can charge them as one 8 x 2=16 AH battery ?
Dan G
On Monday, December 31, 2012 9:49:58 PM UTC-5, Dan G wrote:
> I would like to connect my 2 8AH batteries to one Solar panel for charging while the glider is in its trailer. I will use a controller and I have 2 separate sockets in the glider-one per battery. I thought to simply split the wires coming out of the controller to the two batteries/sockets but I came across this: http://www.morningstarcorp.com/en/support/library/ALL.APP.Isolated_banks_1_controller.01.EN.pdf, Any suggestions? Dan G

[[email protected]]

On Wednesday, January 2, 2013 7:28:54 AM UTC-8, Dan G wrote:
> Thanks for the advice.
>
> Now-if I connect these two batteries in oarallel- do I still need the two separate systems or I can charge them as one 8 x 2=16 AH battery ?
>
> Dan G
>
> On Monday, December 31, 2012 9:49:58 PM UTC-5, Dan G wrote:
>
> > I would like to connect my 2 8AH batteries to one Solar panel for charging while the glider is in its trailer. I will use a controller and I have 2 separate sockets in the glider-one per battery. I thought to simply split the wires coming out of the controller to the two batteries/sockets but I came across this: http://www.morningstarcorp.com/en/support/library/ALL.APP..Isolated_banks_1_controller.01.EN.pdf, Any suggestions? Dan G


Dan,

The circuit you presented already is a parallel circuit in regards the batteries. Looking at it, I'm assuming the diodes are there to prevent damage to the batteries & the controller if one of them is hooked up reverse. In that case, I'd use two diodes.

Regards,

Chris C.

[Dan G[_2_]]

On Wednesday, January 2, 2013 10:42:22 AM UTC-5, wrote:
> On Wednesday, January 2, 2013 7:28:54 AM UTC-8, Dan G wrote: > Thanks for the advice. > > Now-if I connect these two batteries in oarallel- do I still need the two separate systems or I can charge them as one 8 x 2=16 AH battery ? > >
OOPS I neant using one controller for 2 batteries connected in parellel.
Dan
Dan G > > On Monday, December 31, 2012 9:49:58 PM UTC-5, Dan G wrote: > > > I would like to connect my 2 8AH batteries to one Solar panel for charging while the glider is in its trailer. I will use a controller and I have 2 separate sockets in the glider-one per battery. I thought to simply split the wires coming out of the controller to the two batteries/sockets but I came across this: http://www.morningstarcorp.com/en/support/library/ALL.APP.Isolated_banks_1_controller.01.EN.pdf, Any suggestions? Dan G Dan, The circuit you presented already is a parallel circuit in regards the batteries. Looking at it, I'm assuming the diodes are there to prevent damage to the batteries & the controller if one of them is hooked up reverse. In that case, I'd use two diodes. Regards, Chris C.

[JS]

ZAP:
The HQRP looks great. I wonder if three conductor cable (for example, commonly available cable reels) can be used with this. Do you know if the charger read 0 Ohms measured between the two battery negative terminals?
Jim

On Tuesday, January 1, 2013 6:26:13 PM UTC-8, RAS56 wrote:
> I took the easy way out and ordered one of these:
>
> http://www.amazon.com/gp/product/B002LC72W4/ref=oh_details_o05_s00_i00
>
> ZAP

[Scott[_7_]]

On 1-2-2013 15:42, wrote:

> Dan,
>
> The circuit you presented already is a parallel circuit in regards the batteries. Looking at it, I'm assuming the diodes are there to prevent damage to the batteries& the controller if one of them is hooked up reverse. In that case, I'd use two diodes.
>
> Regards,
>
> Chris C.

I didn't look at the circuit, but diodes are usually installed in series
between the panel and the battery to keep them from discharging through
the panel at night when it's dark and they aren't charging.

Scott

[[email protected]]

Scott,

First off, I'm a student pilot so I do not post on this forum much because I try to stay silent and learn from you all. That being said, I do have some knowledge with electronics. My initial assumption was that the diodes will act as an rectifier to prevent reverse polarity connections with the batteries. However, the solar cells could become a "load" at night and the situation you present did happen if there were not diodes there to prevent that. However, I have to believe the controller's internal circuits would prevent that from happening. So, I'll admit, my knowledge of the controller is limited. Anyone have some input on this?

Chris,

[RAS56]

Jim,

I am unsure of the question you are asking me...But all I use is a couple of lengths of 2 conductor cable to each battery. If you can be a little more detailed for this non-electrical engineer type, I am glad to do a little research for you.

Rob
ZAP

[JS]

Rob metered his charge controller and discovered that the negative terminals on the HQRP Duo Charge Controller are common.
A three conductor cable can be used for two batteries.
Jim