Battery & Charger Help

[Spaniard]

I have a 30 footer cabin cruiser with no generator. At the moment, I have installed a Charles Marine charger Sp 2000 series (capable to charge three batteries at the same time) and two Optimas 55 AH connected to a A & B switcher.

Since I have the space, what I would like to do is buying a large deep cycle battery so i could connect it to an inverter and run all my electronic needs (stereo, lights, TV, and fridge) with no worries. Someone advice me to buy two 6volt golf cart batteries,as they normally have a larger capacity than the marine ones. But I would have to buy two of them in order to make them 12Volts.

My main concern is the Charles Marine Charger and the other two batteries, as I am not sure if the charger will be able to handle different capacity batteries (two at 55 AH and one 155AH, for example), and if it does if it would affect the other two I already have.

Thank you in advance for any suggestions...

 

[Silvertip]

Re: Battery & Charger Help

Battereis of different capacities is not a problem from a single output charger. Batteries of different technology is an issue since charging "profiles" may be different than lead-acid types. With lead-acid batteries the battery itself becomes the regulator, each takes what it needs.

 

[Spaniard]

Re: Battery & Charger Help

Thank you so much, Silvertip, for your response. Thus, if that is the case, would you have any recommendations as far as large capacity batteries that would match the type of the Optimas?

Also, I assume that buying an expensive power inverter would a safe assumption; however, does anyone know of a relative inexpensive ($300 - 400) inverter (1000 watts, at the very least) that is reliable?

Thank you in advance.

 

[Silvertip]

Re: Battery & Charger Help

With a total of three outputs on your charger, you would have one output to each of the three batteries so as long as all three batteries have the same charge profile (lead-acid) you don't have an issue in that regard. Since you plan to run an inverter the battery that powers it should be as large as you have room and budget for. Remember, to get 120 watts of 120 volts AC (about 1 amp) OUT of an inverter, you need to put 1200 watts of 12 volts DC (about 10 amps) INTO that inverter. There are losses in that conversion as well. Lastly, you don't need to spend that much money for a 1000 watt inverter.

Check right here on the iBoats store for Xantrex and Pro-Mariner. Only if you are looking for a true siine-wave inverter will you need to spend in excess of $300 - $400.

 

[bruceb58]

Re: Battery & Charger Help

Remember, to get 120 watts of 120 volts AC (about 1 amp) OUT of an inverter, you need to put 1200 watts of 12 volts DC (about 10 amps) INTO that inverter.

Silvertip...12V @ 10A is 120W..not 1200W.

The output power of an inverter is going to be equal to the input power of an inverter times the efficiency of the inverter. For example, a 95% efficient inverter will put out 95W of 110VAC with 100W 12V DC input.

 

[Spaniard]

Re: Battery & Charger Help

Thank you, Bruce, for the clarification. Believe it or not, I assumed it was a mistype from Silvertip, as he explained things easy enough for this Spaniard to understand... Let's see:
If I wanted to run my ice maker (3 amps @120volts) on a battery power ( I am realizing now that will not be very smart on my part) I would need enough 12volt power to run 360 watts which would be a constant of 30 amps @ 12volts. Am I correct? If so, I see that would be crazy, as I don't think I could get a 12 volt battery that will last more than 2 hours at that amperage.

I guess i better forget the ice maker and concentrate my efforts on the following 12 volts applications: TV (4 amps), Blender (12 amps), Fan ( I am not sure of the amps), and from time to time the Microwave (50 amps for 2 minutes or so, per time).

With all this, I still am looking for the right battery. I went to Battery Plus, but sales person (in both occasions) seemed to know less than I do, but he was very polite and doing his best. What size of battery should I get to use this applications from time to time, for an overnight? I know it needs to be AGM, to be the same than the Optimas (for the charges purposes).

 

[bruceb58]

Re: Battery & Charger Help

I probably would go with 2 6V Trojans for my house battery. You would have to get a different charger than what you are using to charge your Optimas. If you had not already bought them, I would have suggested getting lead acid instead of them.

 

[Silvertip]

Re: Battery & Charger Help

Silvertip...12V @ 10A is 120W..not 1200W.

The output power of an inverter is going to be equal to the input power of an inverter times the efficiency of the inverter. For example, a 95% efficient inverter will put out 95W of 110VAC with 100W 12V DC input.

Arrrrgh -- I did it again. This time I'll blame it on Vicodin and one finger typing. Had shoulder surgery.