1 House battery

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starfish
Posts: 30
Joined: Tue Feb 05, 2019 2:21 pm

1 House battery

Post by starfish »

Hello Forum,

my 2005 350 has (2) 4d house batteries, I just found that one is fried and needs to be replaced.
my question to all is can my 1 house battery sustain overnight systems that include: anchor light, inside fans, ridge, water pump etc? Or am I just asking for troubles?

New battery will be arriving on Friday, so I can always postpone my current plans.

thanks
Ed
Ed Kleinstuber
s/v Starfish
C350 #333
wolfe10
Posts: 587
Joined: Mon Dec 11, 2006 2:58 pm
Location: Ft Myers Florida

Re: 1 House battery

Post by wolfe10 »

If that one battery is in good condition, is fully charged and you are conservative with your use of power, yes one can hold you overnight.

Old, with diminished capacity, not fully charged or you use a lot of power-- you may not be able to start the engine in the morning.

Running on one battery overnight is actually what many of us do as a common practice-- run on battery #1 on odd evenings and #2 battery on even evenings. That way we insure that one battery is good to start the engine and we rotate which battery is discharged.

Discharging down to 12.2 VDC (as measured under no load) is OK. I would probably check it around midnight and if below about 12.4 VDC would run the engine at 1,200 RPM or so for long enough that amps going into the battery had dropped off to below 10 amps. If below 12.4 VDC at midnight, worse case is set the alarm for 3 AM and recharge again.
Brett Wolfe
C350 #180
"Vindaloo"
Ft Myers FL
KenKrawford
Posts: 614
Joined: Wed Nov 02, 2005 8:54 pm
Location: Atlanta, GA

Re: 1 House battery

Post by KenKrawford »

Your refrigerator is almost certainly the main power consumer of all the things you mentioned. As Brett advised, if your voltage is below 12.4, consider charging via the engine AND shutting off the fridge til morning. You may be able to coast until morning. Be sure ALL electronics are off when cranking the engine the next morning.
My battery philosophy is somewhat different. Discharging lead acid batteries below 50% of their capacity will greatly reduce their lifespan. I have 4 golf cart batteries wired together to form a 420 amp hour bank. I also have a group 27 battery that is used only for starting if the house bank drops too low. I've never depleted the house bank so much that I had to use the starting battery.
It's highly recommended to do an energy audit and make a rough estimate of how many amp hours you consume in a 24 hr period. If you don't know the amperage draw of a device just divide the wattage by 12.6. Multiply that value by the number of hours the device runs in a 24 hr period. There are also meters that will measure how many amps you have consumed and how many you have replaced via solar, charger, alternator, etc.
Ken Krawford
Message Board Moderator
C350 # 351
Lake Lanier, GA
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