Use a normal car battery for solar panel?

[newhaul]

Mostly the price and footprint is smaller and individual weight.
Here's a link to all you asked for about batteries.
What Is A "Deep Cycle" Battery? Photo Gallery by Compass Marine How To at pbase.com

[Nicks]

Originally Posted by newhaul

Mostly the price and footprint is smaller and individual weight.
Here's a link to all you asked for about batteries.
What Is A "Deep Cycle" Battery? Photo Gallery by Compass Marine How To at pbase.com

Ah yes, wow. I just see that it's almost half the price! That's amazing. I will definitely look further into that!

And making 2 6v's into a 12v is just connecting positive to positive and negative to negative and then only pull loads from one battery?

[skipmac]

Originally Posted by Nicks

What exactly is the advantage of running 2 of those in series, compared to just having a 220amp 12v battery? I seem to be missing that

Several

1. Most large 12V batteries, regardless of the name, are not true deep cycles batteries IE don't gave the very thick, heavy lead plates and other features.

2. A 12V 220 amp hour battery weigh around 80-100 lbs. Two 6V 220 amp hour batteries half that each. Lot easier to move around and if you drop one it won't go straight through the bottom of the boat and sink you. Plus my back isn't what it used to be and hauling 100 lbs up and down the companionway ladder just isn't fun.

[Nicks]

And making 2 6v's into a 12v is just connecting positive to positive and negative to negative and then only pull loads from one battery?

Woops, that was wrong.

Connect + to - and use + on one and - from the other battery.

[skipmac]

Originally Posted by Nicks

And making 2 6v's into a 12v is just connecting positive to positive and negative to negative and then only pull loads from one battery?

NO!!!

That is parallel connection. You want series connection.

Boat ground to negative terminal on one battery. That battery positive to the negative of the second battery. The second battery positive to the boat's positive connection.

Series connection, voltage adds so 6V + 6V = 12V BUT capacity in amp hours stays the same. 220 amp hour at 6V + 220 amp hour at 6V = 220 amp hour at 12V

Parallel, voltage stays the same but the amp hours add up. So 12V 220 amp hour + 12V 220 amp hour = 12V 440 amp hour.

[Nicks]

Originally Posted by skipmac

NO!!!

That is parallel connection. You want series connection.

Boat ground to negative terminal on one battery. That battery positive to the negative of the second battery. The second battery positive to the boat's positive connection.

Series connection, voltage adds so 6V + 6V = 12V BUT capacity in amp hours stays the same. 220 amp hour at 6V + 220 amp hour at 6V = 220 amp hour at 12V

Parallel, voltage stays the same but the amp hours add up. So 12V 220 amp hour + 12V 220 amp hour = 12V 440 amp hour.

Haha yeah I thought of that right after I posted Got a bit confused as I also just looked at solar panels which I needed to wire in a parallel connection

[denverd0n]

I used to live near (and shop in) a supermarket called Pac-n-Sav. So I use that to remember the difference between parallel and serial.

Parallel Adds Current - n - Serial Adds Voltage

...Pac-n-Sav!