# Using marine battery

8 Posts
Nov 1, 2014 11:28 am
Using marine battery

Hello guys,
I am trying to restart my system and cant afford to by the batteries that I need new now. Bought two used Rolls 6V 450AH from another guy who upgraded his system had to give them back. Whenever the fridge starts up my system shuts down, the batteries could not stand up to the surge. Bought a marine battery thinking that 675 CCA would do the trick, it did not. What am I doing wrong here? For now just want to deliver power to some appliances when the sun shines until i can put enough money together to build a decent system. Have three panels 270w each, charge controller XW-MPPT60-150 and a noname Chinese inverter . Took me six years to get this far bought one at a time, electricity cost in Jamaica is too high have to get of the grid somehow.

47 Posts
Nov 18, 2014 12:38 pm
Re: Using marine battery

CCA have nothing to do with sizing an off-grid battery, that is the cold crank amps to start an engine.You need to select based on amp hours (ah).

With the 2 Concorde batteries you had, I assume you wired them in series to get 12V 450ah.

You need to know what loads you are powering to determine the size of the battery bank needed. How much power does it draw, and for how many hours a day.From that, you can figure out what you need for batteries.You can use the loads calculator to help.http://www.altestore.com/store/calculators/load_calculator/ , then go to the off-grid calculator to use that number to size the batteries

Let's also figure out how much power you are making with your panels.270W x 3 = 810W x 6 sun hours x.67 inefficiencies = 3256wh made a day. 3256Wh /12V=271 amp hours. 271ah x 2 = 542 ah 12V battery bank to hold the power you make.

Hope that helps.

Amy
altE Store
Solar Queen

« Last Edit: Dec 1, 2014 10:38 am by Amy Beaudet »

8 Posts
Nov 19, 2014 05:05 pm
Re: Using marine battery

They where in series, but they were no good. What I am trying to satisfy is the start up need of my refrigerator. Whenever it starts up the battery drops below 10v and the inverter shuts down (low voltage protection). I thought the CCA of the marine battery would take care of that. instead of waiting to buy the right batteries, I would  used the system until then. Not thinking about storage now, just when the sun is up I can run a few things and the savings go towards buying the right batteries. I designed the system that it switch between the grid and the solar system automatically when the battery is below 11.5v for 2 minutes switch to grid and switch back to solar when at 13v.

47 Posts
Nov 24, 2014 10:36 am
Re: Using marine battery

The problem remains that the battery is too small for the load. CCA has nothing to do with it. When there is a surge, the inverter pulls the power from the battery, and if the battery amp hours is too small, there's not enough power in the battery to support the surge, and the inverter pulls the voltage down. Can you check the battery and see if it lists the amp hours on it?

My only other guess is that the cheap inverter can't handle the surge of the fridge, do you know what the power spec of the inverter are?

8 Posts
Nov 24, 2014 08:53 pm
Re: Using marine battery

its not written on the battery, but here is whats on it 600 CCA, 160 min RC and a search on the internet tells me it is 60AH
The inverter 2000W surge 4000W
« Last Edit: Nov 24, 2014 08:56 pm by A. Hayles »

47 Posts
Dec 1, 2014 11:06 am
Re: Using marine battery

60ah is waaaaaay too small. If you figure the surge of a fridge when the compressor turns on can be around 600W or more, that's trying to pull about 50 amps from the battery (600W/12V=50A). It just can't handle that kind of draw. I understand trying to save money with a small battery, but it just can't handle the kind of power you are tying to pull out of it.

You are also trying to put too much in at once with the 270Wx3=810W of solar. If you figure 810W x 6 sun hours x.67 losses = 3256 watt hours generated in a day.  You can't use more than half the capacity of your battery, so you have 30ah x 12V=360 watt hours capacity in that battery.

8 Posts
Dec 1, 2014 11:07 pm
Re: Using marine battery

I am not looking to store and use. I want the battery to do what they say these type of battery was designed for, to deliver a burst of power in seconds, the way I set the system up, the battery does nothing after that, well take back some charge (like starting a car). When the fridge is running it consumes 150w to 160w. At times the array produce 200w plus by 10am at mid day 600w to 700w.  I just have to keep fighting with it until I get it right. I know that at the end of the day to get the best out off the array is to get decent batteries. but that's not now. Thanks for the advise.

1 Posts
Dec 3, 2014 03:45 pm
Re: Using marine battery

What you need to realize is that in this application... the CCA has nothing at all to do with it. Your inverter is what is making the surge , and the battery bank behind it can't give the inverter enough power all at once. Not because of the CCA that's not how an inverter works. You don't have enough total battery storage to let the inverter handle the load.

47 Posts
Dec 3, 2014 04:30 pm
Re: Using marine battery

Thanks for the backup Jason.

You say you want to use the battery the way it was intended, but you are not.It was not designed to power an inverter with a huge surge. Don't throw good money after bad trying to do what they are not able to do, get a bigger battery bank, and it will work.

8 Posts
Dec 4, 2014 12:25 am
Re: Using marine battery

I have tested it before with an ordinary car battery, and it worked. That battery was a year old. so I thought a marine battery would be better. I know I need a good battery bank. That is why I am attempting to cut my bill help me save more to achieve that goal in a shorter time. If I get to save 2kw per day, at the end of the year I can buy 4 gulf cart batteries with the savings alone. That's why I am determined to having the system up and running.
Any way burrowed a 2 farad cap from a friend last night put it close to the inverter , will have more time on the weekend to see if it really helps.

1 Posts
Jan 4, 2015 12:43 am
Re: Using marine battery

I have a similar situation as you.  How are you using the capacitor?  As a start or run?

Disclaimer and Disclosure

The Alternative Energy Store, Inc reserves the right, within its sole discretion, to refuse or delete any posting or portion thereof, or terminate or block the access to this forum.

The opinions and statements posted on this forum are the opinions and statements of the person posting same, and do not constitute the opinion or act of the Alternative Energy Store, Inc (AltE). The Alternative Energy Store, Inc does not endorse or subscribe to any particular posting. No posting shall be construed as the act or opinion of the Alternative Energy Store, Inc.

## Share

Click on an icon to share! If you don't see the method you want, hover over the orange "+".