Solar panel to 2 batteries...

[bcarroll]

This is a total newb question but...
I just purchased a 100W solar suitcase to use on my 2 12V batteries.
I know enough about electricity to know I don't know what I'm doing and don't want to do anything wrong.
I have looked on line and it says I can hook it up but it says to do so on the "lead" battery....which one is the lead batter?
Do I just pick one and that's the lead battery?
Do I hook up the negative to one battery and the positive on the other?
Please help my ignorance...

[westend]

bcarroll wrote:

BFL13 wrote:
The diagram above and talk of the "lead battery" is for the "un-balanced " (ie wrong) way to do it. The other guys have it right about putting the pos on one and the neg on the other for a "balanced" set.

Ok, good. Thanks! Now I just have to hope the aligator clips will span 2 batteries.

Pull the clip wires apart until they reach.

[2oldman]

Maybe it means the battery has lead in it.

[bcarroll]

BFL13 wrote:
The diagram above and talk of the "lead battery" is for the "un-balanced " (ie wrong) way to do it. The other guys have it right about putting the pos on one and the neg on the other for a "balanced" set.

Ok, good. Thanks! Now I just have to hope the aligator clips will span 2 batteries.

[BFL13]

The diagram above and talk of the "lead battery" is for the "un-balanced " (ie wrong) way to do it. The other guys have it right about putting the pos on one and the neg on the other for a "balanced" set.

[bcarroll]

RoyB wrote:
With the smaller SOLAR PANELS I would think only in the term of getting my batteries topped off. A typical 100WATT SOLAR PANEL will only give you around 5AMPS OF DC current when in high sun. Two Panels will make this 10AMPS of DC CURRENT.

This is great if your trailer is sitting in the sun for several hours and will slowly bring up your batteries to full charge over time.

All batteries have the same charge rate depending on the DC VOLTAGE and amount of available DC CURRENT for them to use.

A typical 12VDC deep cycle battery will want to see around 14.4VDC with around 17-20AMPS OF DC CURRENT available to use if you want to bring this battery up from its 50% charge state to its 90% charge state. This will take around three hours of charge time for me with my setup. If you have multiple batteries in the setup then you will want to have 17-20AMPS OF DC CURRENT available for each battery. i.e. your two batteries will want to see a total of 34-40AMPS DC current if you expect them to be charged in THREE HOURS TIME doing the 50% to 90% charge rate.

As you can see the two 100WATT Solar Panels will not do this for you in the three hour window. It will take much longer to get them charged back up. Then you will fall into the high sun going away after 6-7 hours depending where you live. Of course after dark you will not get any charge coming from the solar panels.

Just passing all this along to get you thinking what you will be doing with your two 100WATT SOLAR PANELS. If you never drop your two batteries down much with using them the two 100WATT PANELS will bring them back up real nice...

I would experiment with your solar setup sitting at home for a couple of days so you will know what to expect using the things you want to have on running off the batteries. Most of us just have the trailer lights and the home entertainment items going between 6PM and 11PM.

The idea with batteries is to never drop them below the 50% charge state or around 12.0VDC without re-charging right away. Going below the 12.0VDC charge level will start doing damage to your battery. Your batteries will last a long time following this simple rule...

Just some of my thoughts here. I have been living off my 255AH battery banks for several years camping off the power grid. I am just now starting to think SOLAR PANELS to supplement my 2KW Generator charging of the batteries.

Roy Ken

Thanks for the input! I plan to simply top off my batteries during the day.
The Solar suitcase I have is 100w total(2 50w panels).
I don't want to be limited to Full hook up sites, and since I have electric awning, electric stablizer jacks, and electric hitch jack, I want to have enough juice in the batteries to hook up and go home after 3-4 days of camping.
I don't plan on using a lot of electricity(lights(about half are LED), cpap, detectors, water pump).
This was my first step into solar to see how it will work.

[time2roll]

If the batteries are in parallel connect the Solar + to the positive of one battery and Solar - to the negative of the other battery.

[RoyB]

With the smaller SOLAR PANELS I would think only in the term of getting my batteries topped off. A typical 100WATT SOLAR PANEL will only give you around 5AMPS OF DC current when in high sun. Two Panels will make this 10AMPS of DC CURRENT.

This is great if your trailer is sitting in the sun for several hours and will slowly bring up your batteries to full charge over time.

All batteries have the same charge rate depending on the DC VOLTAGE and amount of available DC CURRENT for them to use.

A typical 12VDC deep cycle battery will want to see around 14.4VDC with around 17-20AMPS OF DC CURRENT available to use if you want to bring this battery up from its 50% charge state to its 90% charge state. This will take around three hours of charge time for me with my setup. If you have multiple batteries in the setup then you will want to have 17-20AMPS OF DC CURRENT available for each battery. i.e. your two batteries will want to see a total of 34-40AMPS DC current if you expect them to be charged in THREE HOURS TIME doing the 50% to 90% charge rate.

As you can see the two 100WATT Solar Panels will not do this for you in the three hour window. It will take much longer to get them charged back up. Then you will fall into the high sun going away after 6-7 hours depending where you live. Of course after dark you will not get any charge coming from the solar panels.

Just passing all this along to get you thinking what you will be doing with your two 100WATT SOLAR PANELS. If you never drop your two batteries down much with using them the two 100WATT PANELS will bring them back up real nice...

I would experiment with your solar setup sitting at home for a couple of days so you will know what to expect using the things you want to have on running off the batteries. Most of us just have the trailer lights and the home entertainment items going between 6PM and 11PM.

The idea with batteries is to never drop them below the 50% charge state or around 12.0VDC without re-charging right away. Going below the 12.0VDC charge level will start doing damage to your battery. Your batteries will last a long time following this simple rule...

Just some of my thoughts here. I have been living off my 255AH battery banks for several years camping off the power grid. I am just now starting to think SOLAR PANELS to supplement my 2KW Generator charging of the batteries.

Roy Ken

[bcarroll]

NinerBikes wrote:

bcarroll wrote:

Dakota98 wrote:
Connect in parallel as show.

Top battery is "lead"

Maybe I don't have my batteries hooked up correctly... I have the negative from the trailer going to one battery, and the positive from the trailer going to the second battery... of course neg to neg and pos to pos from one battery to the other.

Your batteries are hooked up correctly, and you should hook up the clamps from your solar panels at the exact same locations as the trailer terminals are hooked up on the batteries. Duplicate it and you will be fine. Positive red goes on one battery terminal of the first battery, and the negative black goes to the second battery and it's negative terminal.

Thank you! when it comes to electrical stuff, I need a lot of hand holding for my own confidence.
I take it I could have the trailer to going to one battery, and then I would only need to hook the panels up to one battery...?

[bcarroll]

robatthelake wrote:
What You have is a fine way to introduce yourself to Solar ,many of Us began with less.
If You have 2 x 12 Volt Batteries they are connected to each other in Parralell ...Positive to Positive and Negative to Negative. The Lead Battery is the one that has the Positive feed attached to the Fuse Panel!

If You have 2 x 6 Volt Batteries they are connected to each other in Series! Positive on One to the Negative on the Other. This results in One Large 12 Volt Battery. In this case the Lead Battery would be the One whose Positive Terminal is connected to the Fuse Panel.

In either case be sure that The Wire from the Solar array is connected + Positive to +. And the Legative is connected to the - Negative or Ground to the Frame!

May I suggest that You Google Search " The 12 Volt Side of Life"

Thanks for the feedback... I do have + to + and - to - between the batteries (I did get that much from the 12v side of life when I got my second battery), but to hook up the portable solar panels to the battery is where I'm in the dark at.
For all I know it doesn't matter and I'm making a bigger issue of it than it is. 🙂

[NinerBikes]

bcarroll wrote:

Dakota98 wrote:
Connect in parallel as show.

Top battery is "lead"

Maybe I don't have my batteries hooked up correctly... I have the negative from the trailer going to one battery, and the positive from the trailer going to the second battery... of course neg to neg and pos to pos from one battery to the other.

Your batteries are hooked up correctly, and you should hook up the clamps from your solar panels at the exact same locations as the trailer terminals are hooked up on the batteries. Duplicate it and you will be fine. Positive red goes on one battery terminal of the first battery, and the negative black goes to the second battery and it's negative terminal.

[bcarroll]

Dakota98 wrote:
Connect in parallel as show.

Top battery is "lead"

Maybe I don't have my batteries hooked up correctly... I have the negative from the trailer going to one battery, and the positive from the trailer going to the second battery... of course neg to neg and pos to pos from one battery to the other.

[robatthelake]

What You have is a fine way to introduce yourself to Solar ,many of Us began with less.
If You have 2 x 12 Volt Batteries they are connected to each other in Parralell ...Positive to Positive and Negative to Negative. The Lead Battery is the one that has the Positive feed attached to the Fuse Panel!

If You have 2 x 6 Volt Batteries they are connected to each other in Series! Positive on One to the Negative on the Other. This results in One Large 12 Volt Battery. In this case the Lead Battery would be the One whose Positive Terminal is connected to the Fuse Panel.

In either case be sure that The Wire from the Solar array is connected + Positive to +. And the Legative is connected to the - Negative or Ground to the Frame!

May I suggest that You Google Search " The 12 Volt Side of Life"

[Dakota98]

Connect in parallel as show.

Top battery is "lead"
For reference only, ignore the A/H, as shown. Yours will be different