Big Inverter + Batteries and the Air Conditioner

[gadgetman]

batteries should never be run down below 50 %. 12.65 to 12.7 is a full charged battery. Readings are taken with all loads off for 2 hrs. every .10 of a volt is 10% of your battery.


So 12.2 is you max draw at 50%  you should not go lower. Going under 50% drastically reduces your total charge cycles you can get from your batteries. Only using 30% is best.


If your batteries can get 1500 charge cycles and you keep going to 50% you may only get 300 cycles out of them.


Understand that 12.2 volts with loads on is not a 50% drain. Turn those loads off and you will see the voltage rise .10 to .25.

[eXodus]

thanks for the information. 12.2v is a nice idea but depends on the temperature.


Here in sunny Florida my batteries would be at 40% at 12.2v. My Batteries have fully charged about 12.9v - 13V



Yeah I'm weekend warrior with low use, I get about 3 days out of my batteries in warm weather (12.3v)
I normally drive every second day so there is charging. With my profile I'm gonna use up maybe 50 cycles a year or less.

[LJ-TJ]

So what are you guys using to read the charge in your batteries. Is there some kind of gauge you can install? Or to you just go out every few days with a hydrometer.

[DaveVA78Chieftain]

You can use a voltmeter

Or

You can use a fancy Bogart TriMetric http://www.ebay.com/sch/i.html?_nkw=%28Trimetric%2CTri-Metric%29&_sacat=0&_odkw=%28Trimeteric%2CTri-Metric%29&_osacat=0&_trksid=m194&ssPageName=STRK:MEFSRCHX:SRCH

Or

A poor mans version of the TriMetric: http://www.ebay.com/itm/DC-120V-150A-Volt-Amp-Combo-Meter-Battery-Charge-Discharge-Remaining-Capacity-/181152599371?pt=LH_DefaultDomain_0&hash=item2a2d894d4b

I have to install the Poor Mans option I purchased to see how it works out.  Myself, I like being able to constantly monitor the voltage and current.  The one I currently have requires you to select between current and voltage.

Dave

[eXodus]

I'm using a Voltmeter, from amazon:

http://www.amazon.com/3-2-30V-0-56inch-Digital-Voltmeter-Two-wire/dp/B00L8HK2H0/ref=sr_1_16?ie=UTF8&qid=1427454717&sr=8-16&keywords=voltmeter+install

I put's out the same values as my Fluke Multimeter.

Dave maybe this would be something for you:
the very poor mans version: http://www.amazon.com/beesclover-Digital-Ammeter-Voltmeter-BeesClover/dp/B00C7MJ5LE/ref=pd_sim_sbs_hi_2?ie=UTF8&refRID=1JT5XHN8TGMZGGVGWD0M

[eXodus]

I didn't intend so while working on other projects but I did it 


My Goldstar 5000 BTU window A/C (under 500w) mounted through the wall is running of my 1000w Bestek Inverter with two 6V 220Ah Golf Cart batteries.
[smg id=6984]


I did run it for 10min and the voltage doesn't even dropped. Probably would run down the batteries in 2 hours, but the compressor started cycling.
So could probably run this A/C while driving and cool the rear of my coach. But normally I just open the roof vents and let it be.