House Battery Upgrade - Where to put 'em??
Hi all! We're getting ready to upgrade our house battery setup (adding a nice pure sine inverter, etc). We're in a 2003 Fleetwood Flair 33R. It has the stock pair of 6V batteries. They're doing fin...
Forum Discussion
travelingbard wrote:This would be the correct size of inverter.
Looking at the 3000 watt inverter models...
About the AC math: a conventional 13.5K BTU air conditioner may draw up to 25 amps of current at 120V when starting from lock rotor position. It probably operates at close to 15 amps when running. That is 15 amps at 120V. You can interpolate that to 12V through the inverter by a factor of 10X, allowing for inverter loss and wiring. You're looking at 150 A of draw from your batteries. A 6 fold GC2 6V bank would have a capacity of (3x225AH)=675AH at the 20hr rating. Traditionally, batteries are only allowed to be drawn to 50% of capacity, in the above example, 337 AH. After allowing for the Peukert effect of the large draw and the lock rotor draw, you may get 2 hrs. of run time from that bank but real life use tells me it would be less because the inverter will shutdown when you approach 11 or 11.5 volts DC. The above considers no duty cycle but a continuous run time. It also assumes a 12V battery system. That may or may not be typical use in your location.
If you need off-grid power from batteries to run an AC unit, you should be looking at LIthium technology, IMO. There is a Forum member that does accomplish what you envision but they limit the use of the AC to a few hours a day.
To your original question--put the batteries where it's convenient to service them and as close as possible to the 12V distribution panel, the converter, and inverter. GC2 6V's weigh 70 lbs. A sliding tray would be a great thing to have.
