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Adding Batteries

Posted: November 4th, 2017, 10:18 pm
by ataylor233
I Have a 1986 Carver 3207 and i would love to add about 2 more batteries so that i can run an inverter. My question is is there a specific battery set up for the house bank? Should i just add an additional 2 batteries to maybe battery 2 on the switch in parallel ? Should i some how try and separate the house bank and started batteries? i'm kind of lost here because I want to add 2 100 ah batteries .

i'm looking at at possibly a 1000 watt inverter which maybe over kill i may be running a 32 inch smart TV and a 19 inch in the aft cabin so the kids can watch TV while underway . over all i would like a inverter charger so i can use it for all outlets.
I also want to sometimes run the fridge on 12 volt .

Re: Adding Batteries

Posted: November 5th, 2017, 9:51 am
by bud37
In my opinion this will depend on how much you want to spend.........again IMO the ideal setup would be a separate dedicated house bank of all the same size batteries and dedicated bank of start batteries for each engine. The house bank would power all the 12volt equipment on your boat when the engines are off.
If you add those two batteries you mentioned to an already existing bank then try to have all the batteries in that bank the same size or you may encounter charging problems.As for the amount of amp hour required, add up all your equipment amp draws and size battery bank accordingly.......for example you have 200 amp/hour draw then to keep your battery draw down to 50% or greater you would require a 400 amp/hr bank......remember the charger in all this......simply, if you have a 20amp charger then it would take 10 hours to put back the 200 you took out with no other interference.I hope this helps a bit.
Is your fridge not 110/12 volts?

Re: Adding Batteries

Posted: November 5th, 2017, 10:04 am
by ataylor233
That helps greatly I will likely separate the 2 banks and run 4 6 volt golf cart batteries for a 12 volt 400+ ah bank just have to get ready to spend the cash... Should be fun

Re: Adding Batteries

Posted: November 5th, 2017, 10:30 am
by bud37
Oh let me add...when you calculate your amp draws, remember to also use the amount of time they are running....eg your fridge at 8amps may only run for 30 minutes an hour, so that would be a 4 amp/hr draw based on 50% fridge on per hour, and so on...... :beergood:

Re: Adding Batteries

Posted: November 6th, 2017, 7:06 am
by Viper
If you're powering up the entire boat by hooking the inverter up to the main panel, you should go with a marine unit. Also keep in mind that very few inverters are designed to be mounted in a gasoline engine compartment, so for safety, don't install one in there unless it specifically states it's ignition protected. Use marine rated hardware for the hook up as these draw a lot of amperage and can be dangerous if improper wiring practices and hardware are used.

Re: Adding Batteries

Posted: November 6th, 2017, 7:32 am
by ataylor233
Viper wrote:Source of the post If you're powering up the entire boat by hooking the inverter up to the main panel, you should go with a marine unit. Also keep in mind that very few inverters are designed to be mounted in a gasoline engine compartment, so for safety, don't install one in there unless it specifically states it's ignition protected. Use marine rated hardware for the hook up as these draw a lot of amperage and can be dangerous if improper wiring practices and hardware are used.



Yes I know thank you for the information I was planning for the aft cabin closet under the stairs.

Re: Adding Batteries

Posted: November 6th, 2017, 11:38 am
by g36
You cannot simply hook up to the panel. Depending on the inverter you need to know if the neutral will also be hot and whether your ground is floating or not in the inverter. You need to see how your neutral bus and gnd are setup in your boat too. I do run my inverter with golf cart house bank and it can work great but make sure you understand the whole picture

Re: Adding Batteries

Posted: November 6th, 2017, 11:48 am
by ataylor233
g36 wrote:Source of the post You cannot simply hook up to the panel. Depending on the inverter you need to know if the neutral will also be hot and whether your ground is floating or not in the inverter. You need to see how your neutral bus and gnd are setup in your boat too. I do run my inverter with golf cart house bank and it can work great but make sure you understand the whole picture


Great advice I've been researching and researching I hope to find someone with more experience with the matter before making any real moves. I've seen allot of golf cart batteries for great prices.

Re: Adding Batteries

Posted: November 6th, 2017, 1:32 pm
by km1125
Great advice in this thread. If you get a chance, see if your library carry's Nigel Calder's Boatowners Mechanical and Electrical Manual It has a LOT of good information on house banks, inverters and A.C. wiring. Also addresses grounding and bonding.

Also consider airflow in your inverter location. As an inverter or charger, it is not 100% efficient. While running, you can expect it to be 80-90% efficient, but that means with a 1000W output, you could have up to 200W being absorbed in the inverter. That is the equivalent heating as a 200W incandescent bulb. If put in a small space with no ventilation, that space will QUICKLY heat up much hotter than you would prefer!!

If you're interested, I have a West Marine/Heart Interface 1500W inverter/charger. I mainly use it just for the charger, but I would part with it and give you a good deal on it.

Re: Adding Batteries

Posted: November 6th, 2017, 2:02 pm
by ataylor233
km1125 wrote:Source of the post Great advice in this thread. If you get a chance, see if your library carry's Nigel Calder's Boatowners Mechanical and Electrical Manual It has a LOT of good information on house banks, inverters and A.C. wiring. Also addresses grounding and bonding.

Also consider airflow in your inverter location. As an inverter or charger, it is not 100% efficient. While running, you can expect it to be 80-90% efficient, but that means with a 1000W output, you could have up to 200W being absorbed in the inverter. That is the equivalent heating as a 200W incandescent bulb. If put in a small space with no ventilation, that space will QUICKLY heat up much hotter than you would prefer!!

If you're interested, I have a West Marine/Heart Interface 1500W inverter/charger. I mainly use it just for the charger, but I would part with it and give you a good deal on it.



how much for the inverter and im going to look for the book now.